300 ppm CO2 ASAP

The website "300 ppm CO2 ASAP" is an alphabetically organized compendium of the views of climate scientists , biologists and other science-informed climate activists advocating the return of atmospheric carbon dioxide (CO2) to about 300 parts per million (ppm) as soon as possible (ASAP) from the present dangerous and damaging 400 ppm CO2.

300.org exists to inform people about the Climate Emergency and the need to reduce atmospheric carbon dioxide (CO₂ ) concentration to a safe and sustainable level of about 300 ppm.

The fundamental position of 300.org is that “There must be a safe and sustainable existence for all peoples and all species on our warming-threatened Planet and this requires a rapid reduction of atmospheric carbon dioxide concentration to about 300 parts per million”. [1].

300.org urges the World to reduce atmospheric carbon dioxide concentration (CO₂) to about 300 parts per million by volume (ppm). In urging a target of an atmospheric CO₂ concentration of 300 ppm, 300.org is informed by the advice of top world climate scientists as set out below.

The World is acutely threatened by man-made global warming due to profligate greenhouse gas (GHG) pollution. The atmospheric CO₂ concentration is currently 387 ppm and increasing at about 2 ppm annually. CO₂ is a major GHG but other GHGs include methane (CH₄) and nitrous oxide (N₂O). The current atmospheric GHG concentration in units of CO₂-equivalent (CO₂-e) and including methane and nitrogen oxides is is about 475 ppm. The average global surface temperature is now about 0.8^oC above that in 1900. [2].

The post-1900 temperature increase of 0.8^oC has already been associated with very damaging climatic disruption, specifically increased sea levels; increased energy of tropical hurricanes; ocean warming; increased melting of glaciers; increased sea ice melting in the Arctic and Antarctic; methane release from the Arctic Ocean and tundra; increased extent of forest fires; island submergence; increased drought; increased floods; coral die off; mass species extinction at 100-1,000 times the rate indicated by the fossil record; hundreds of thousands of climate refugees; increased damage to forests; spread of insect vector-borne disease; and increased human avoidable mortality (avoidable death, excess mortality, excess death). [3, 4, 5]

The consequences of man-made global warming for ecosystems and species survival are already dire at an average global surface temperature that is currently about 0.8^oC above that in 1900. Many scientists now doubt that we can avoid further damaging temperature increases to over 2 ^oC above that in 1900. Thus a poll by the UK Guardian of scientists attending the March 2009 Copenhagen Climate Change Conference found that 90% of respondents did not believe that current political efforts would keep warming to less than 2 ^oC above that in 1900.

According to top UK climate scientist Dr James Lovelock FRS fewer than 1 billion people (evidently mostly European) will survive the century due to First World profligacy and unaddressed man-made climate change. [7].

This dire estimate of Dr James Lovelock of fewer than 1 billion survivors this century from unaddressed, man-made global warming translates to about 10 billion deaths (mostly of non-Europeans and including 3 billion Muslims, 2 billion Indians) in an already-commenced Climate Holocaust and Climate Genocide. [8].

300.org agrees with the Climate Emergency perceptions and goals of the Melbourne-based Yarra Valley Climate Action Group and specifically with what needs to be done. [9].

1. Change of societal philosophy to one of scientific risk management and biological sustainability with complete cessation of species extinctions and zero tolerance for lying.

2. Urgent reduction of atmospheric CO₂ to a safe level of about 300 ppm as recommended by leading climate and biological scientists.

3. Rapid switch to the best non-carbon and renewable energy (solar, wind, geothermal, wave, tide and hydro options that are currently roughly the same market price as coal burning-based power) and to energy efficiency, public transport, needs-based production, re-afforestation and return of carbon as biochar to soils coupled with correspondingly rapid cessation of fossil fuel burning, deforestation, methanogenic livestock production and population growth.

Inspired by the position of Dr Hansen (head, NASA GISS) that “CO₂ will need to be reduced from its current 385 ppm to at most 350 ppm” [10] the world-wide 350.org organization has the position of urging a return of the atmospheric CO₂ concentration to 350 ppm or less ("rounding down" gives "300 ppm CO2"). [11].

The Australian national Climate Action Summit in Canberra (January 2009) involved over 140 community action groups and endorsed a key aim for stabilisation at 300 ppm CO₂ in the atmosphere and strong international agreement in line with what science and global justice demands. [12].

The name 300.org reflects support for the implicit 350.org goal of less than 350 ppm CO₂ (although, as detailed below, a goal of "350 ppm" is clearly inadequate according to leading scientists) and the goal of about 300 ppm CO₂ of the 2009 Australian Climate Action Summit [12], the Australian Climate Emergency Network [13] and the Yarra Valley Climate Action Group [14].

Just as we turn to top medical specialists for advice on life-threatening disease, so we turn to the opinions of top scientists and in particular top biological and climate scientists for Climate Change risk assessment and Climate Emergency facts and requisite actions.For a detailed and documented climate change course see "2011 climate change course" [15]. Other key websites documenting expert opinion include

[1]. Dr Gideon Polya, “How to save the Planet. Accountability, Badge & Credo (ABC Protocol) on MWC News, 14 May 2009: http://mwcnews.net/content/view/30564/42/ ) .

[2]. Dr Andrew Glikson, “The threat to life posed by atmospheric CO2-e over 450 ppm”, submission #34 to the Australian Senate Standing Committee on Economics Inquiry into the Carbon Pollution Reduction Scheme (CPRS), 2009: http://www.aph.gov.au/senate/committee/economics_ctte/cprs_09/submissions/sub34_web.pdf ; see also http://www.aph.gov.au/senate/committee/economics_ctte/cprs_09/submissions/sublist.htm .

[3]. Dr James Hansen (2007), Huge sea level rises are coming – unless we act now”, New Scientist, 2614, 26 July 2007: http://www.newscientist.com/article/mg19526141.600-huge-sea-level-rises-are-coming--unless-we-act-now.html?page=1 .

[4]. Dr John Holdren (2008), “The Science of Climatic Disruption” (power point lecture): http://www.usclimateaction.org/userfiles/JohnHoldren.pdf .

[5]. Dr Gideon Polya (2009), “Global warming, climate emergency” U3A course notes: http://sites.google.com/site/yarravalleyclimateactiongroup/global-warming--global-emergency-course .

[6] David Adam, “World will not meet 2C warming target, climate change experts agree” “, Guardian, 14 April 2009: http://www.guardian.co.uk/environment/2009/apr/14/global-warming-target-2c .

[7]. Gaia Vince (2009), “One last chance to save mankind“, New Scientist, 23 January 2009: http://www.newscientist.com/article/mg20126921.500-one-last-chance-to-save-mankind.html?full=true .

[8]. Dr Gideon Polya, “First World Climate Genocide – global warming to kill 2 billion Indians this century “, Sulekha, 2009: http://gideon.sulekha.com/blog/post/2009/01/first-world-climate-genocide-global-warming-to-kill.htm .

[9]. Yarra Valley Climate Action Group, “Climate Emergency facts and required actions”: http://sites.google.com/site/yarravalleyclimateactiongroup/climate-emergency-facts-and-required-actions .

[10] J. Hansen et al, “Target atmospheric CO2 – where should humanity aim?” : http://arxiv.org/abs/0804.1126 ,

[11]. 350.org: http://www.350.org/mission .

[12]. Greenlivingpedia, “Australian climate Action Summit 2009”: http://www.greenlivingpedia.org/Australian_climate_action_summit_2009 .

[13]. Climate Emergency Network: http://www.climateemergencynetwork.org/ .

[14]. Yarra Valley Climate Action Group: http://sites.google.com/site/yarravalleyclimateactiongroup/Home .

[15]. "2011 climate change course": https://sites.google.com/site/300orgsite/2011-climate-change-course .

[16]. 300.org: https://sites.google.com/site/300orgsite/300-org .

[17]. “300.org – return atmosphere to 300 ppm”; https://sites.google.com/site/300orgsite/300-org---return-atmosphere-co2-to-300-ppm .

[18]. “2001 climate change course”: https://sites.google.com/site/300orgsite/2011-climate-change-course .

[19]. “Carbon Debt Carbon Credit”: https://sites.google.com/site/carbondebtcarboncredit/

[20]. “Cut carbon emissions 80% by 2020”: https://sites.google.com/site/cutcarbonemissions80by2020/

[21]. “Biofuel Genocide”: https://sites.google.com/site/biofuelgenocide/

[22]. "Climate Genocide": https://sites.google.com/site/climategenocide/

[23]. "100% renewable energy by 2020”: https://sites.google.com/site/100renewableenergyby2020/

[24]. “Divest from fossil fuels”: https://sites.google.com/site/300orgsite/divest-from-fossil-fuels

[25]. "Climate Justice & Intergenerational Equity": https://sites.google.com/site/300orgsite/climate-justice

[26]. "Stop Climate Crime": https://sites.google.com/site/300orgsite/stop-climate-crime .

[27]. "300 ppm CO2 ASAP": https://sites.google.com/site/300orgsite/300-ppm-co2-asap .

[28]. "Gas is not clean energy”: https://sites.google.com/site/gasisnotcleanenergy/ .

Below are quotations from leading climate scientists, biological scientists and science-informed climate change activists supporting the need to return to an atmospheric CO₂ concentration in the range 300-350 ppm i.e. after “rounding down” and applying the “precautionary principle” of the lower safe limit, an atmospheric CO₂ concentration of about 300 ppm (the upper limit for the last 800,000 years except for the last half century or so).

(A) INDIVIDUALS

ALLEY, Richard. Dr Richard Alley, a glaciologist at Pennsylvania State University, University Park, Pennsylvania, USA, on the reported slow-motion collapse of the West Antarctic ice sheet (2014): “Very crudely, we are now committed to global sea level rise equivalent to a permanent [2012] Hurricane Sandy storm surge… The possibility that we have already committed to 3 or more meters of sea level rise from West Antarctica will be disquieting to many people, even if the rise waits centuries before arriving.” [45].

[Editor’s note: Core samples indicate that seawater has filled the West Antarctic basins within the past 750,000 years. The atmospheric CO2 has been between 180 and 280 ppm for the last 800,000 years but has increased since the start of the Industrial revolution and is now about 400 ppm and increasing at a record 2.5 ppm per year and energy-linked CO2 pollution is remorselessly increasing (see “300.org – return atmosphere CO2 to 300 ppm”, 300.org: http://sites.google.com/site/300orgsite/300-org---return-atmosphere-co2-to-300-ppm ; US EIA, “Energy-related carbon dioxide emissions”, Table A10: http://www.eia.gov/forecasts/ieo/emissions.cfm ; US National Oceanic and Atmospheric Administration (NOAA) Mauna Loa Observatory, “Trends in Atmospheric Carbon Dioxide”: http://www.esrl.noaa.gov/gmd/ccgg/trends/ ].

[1]. Dr Richard Alley quoted in Thomas Sumner, “West Antarctic ice sheet is collapsing”, Science Now, 12 May 2014: http://news.sciencemag.org/climate/2014/05/west-antarctic-ice-sheet-collapsing .

BROOK, Barrie. Professor Barry Brook (Sir Hubert Wilkins chair of climate change and director of climate science at the University of Adelaide's Environment Institute ): “If the planet is like an oven, it's still possible to turn down the temperature. The number is 300 and the methods will be extraordinary. In 2007, a climate awareness campaign was launched by well-known environmental author Bill McKibben. It was coined 350.org, with the slogan "350 is the most important number on the planet". The figure refers to a target concentration of carbon dioxide (CO2) in the Earth's atmosphere, in parts per million (ppm). This number was drawn from a recent study by a team of climate scientists, led by NASA's Dr James Hansen ... But there is another, more surprising, problem with 350. It's the wrong number. While 350 ppm should give us a reasonable shot at avoiding more than two degrees of warming, that's hardly a safe future to be aiming for. We need only to look at the impacts at less than one degree to know we're already committed to some tough adaptation problems … A target of 300 to 325 ppm CO2 - the levels of the 1950s - is necessary if we wish to cut additional warming and start to roll back the already damaging impacts. As such, 350 is not a target, it's a signpost to a goal. So we're aiming at 350 but the real goal is 300 and we're already at 385”. [1, 2].

[1]. Professor Barry Brook, “Six degrees of separation”, Sydney Morning Herald, 23 March 2009: http://www.smh.com.au/environment/earth-hour/six-degrees--of-separation-for-the-planet-20090324-984c.html .

[2]. Professor Barry Brook, “BraveNewClimate.com: http://bravenewclimate.com/ .

COSTANZA, Robert. Statement by the World's top climate scientists including Professors Robert Costanza, Paul Crutzen (Netherlands Nobel Laureate), James Hansen (US), Hans Joachim Schellnhuber (Germany), in the top scientific journal Nature that atmospheric CO2 must NOT exceed 350 ppm (September 2009):"Our proposed climate boundary is based on two critical thresholds that separate qualitatively different climate-system states. It has two parameters: atmospheric concentration of carbon dioxide and radiative forcing (the rate of energy change per unit area of the globe as measured at the top of the atmosphere). We propose that human changes to atmospheric CO₂ concentrations should not exceed 350 parts per million by volume, and that radiative forcing should not exceed 1 watt per square metre above pre-industrial levels. Transgressing these boundaries will increase the risk of irreversible climate change, such as the loss of major ice sheets, accelerated sea-level rise and abrupt shifts in forest and agricultural systems. Current CO₂ concentration stands at 387 p.p.m.v. and the change in radiative forcing is 1.5 W m^-2 . " [1].

[1]. Johan Rockström, Will Steffen, Kevin Noone, Åsa Persson, F. Stuart Chapin, III, Eric F. Lambin, Timothy M. Lenton, Marten Scheffer, Carl Folke, Hans Joachim Schellnhuber, Björn Nykvist, Cynthia A. de Wit, Terry Hughes, Sander van der Leeuw, Henning Rodhe, Sverker Sörlin, Peter K. Snyder, Robert Costanza, Uno Svedin, Malin Falkenmark, Louise Karlberg, Robert W. Corell, Victoria J. Fabry, James Hansen, Brian Walker, Diana Liverman, Katherine Richardson, Paul Crutzen & Jonathan A. Foley, “A safe operating space for humanity”, Nature, 461, 472-475, 2009: http://www.nature.com/nature/journal/v461/n7263/full/461472a.html .

CRUTZEN, Paul. Statement by the World's top climate scientists including Professors Paul Crutzen (Netherlands Nobel Laureate), James Hansen (US), Hans Joachim Schellnhuber (Germany), in the top scientific journal Nature that atmospheric CO2 must NOT exceed 350 ppm (September 2009): "Our proposed climate boundary is based on two critical thresholds that separate qualitatively different climate-system states. It has two parameters: atmospheric concentration of carbon dioxide and radiative forcing (the rate of energy change per unit area of the globe as measured at the top of the atmosphere). We propose that human changes to atmospheric CO₂ concentrations should not exceed 350 parts per million by volume, and that radiative forcing should not exceed 1 watt per square metre above pre-industrial levels. Transgressing these boundaries will increase the risk of irreversible climate change, such as the loss of major ice sheets, accelerated sea-level rise and abrupt shifts in forest and agricultural systems. Current CO₂ concentration stands at 387 p.p.m.v. and the change in radiative forcing is 1.5 W m^-2 . " [1].

[1]. Johan Rockström, Will Steffen, Kevin Noone, Åsa Persson, F. Stuart Chapin, III, Eric F. Lambin, Timothy M. Lenton, Marten Scheffer, Carl Folke, Hans Joachim Schellnhuber, Björn Nykvist, Cynthia A. de Wit, Terry Hughes, Sander van der Leeuw, Henning Rodhe, Sverker Sörlin, Peter K. Snyder, Robert Costanza, Uno Svedin, Malin Falkenmark, Louise Karlberg, Robert W. Corell, Victoria J. Fabry, James Hansen, Brian Walker, Diana Liverman, Katherine Richardson, Paul Crutzen & Jonathan A. Foley, “A safe operating space for humanity”, Nature, 461, 472-475, 2009: http://www.nature.com/nature/journal/v461/n7263/full/461472a.html .

FANKHAUSER, Samuel. Samuel Fankhauser (economist and climate change specialist at the Grantham Research Institute on Climate Change and the Environment, London School of Economics; member of the UK Committee on Climate Change, a government watchdog that monitors UK climate change policy; former Deputy Chief Economist at the European Bank for Reconstruction and Development (EBRD); served on the 1995, 2001 and 2007 assessments of the Intergovernmental Panel on Climate Change (IPCC)) (2009), was reported by IPS thus: “A future global climate change treaty must limit the concentration of carbon dioxide in the atmosphere to 350 parts per million (ppm), and not 450 ppm, the currently proposed level, Samuel Fankhauser told a meeting of pro-environment legislators from the eight most industrialised countries and emerging economies here. But they felt the goal was not feasible. A British economist and researcher on climate change, Fankhauser said the limit he is urging is the only way to avoid the irreversible bleaching of coral in coastal areas, with all that this implies for people's livelihoods and the environment.”.

Dr Fankhauser was directly quoted thus : “"Action against climate change might cost up to three percent of the world's GDP during the next 40 years," Fankhauser told IPS. "But this price is still cheaper than doing nothing about it…The global climate change sector is already booming. Revenues generated by measures against climate change have surpassed 500 billion dollars in 2008, and could be worth some two trillion dollars by 2020…[500 million people] live within 100 kilometres of reef ecosystems, and benefit from these services…Another important service provided by coral reefs and healthy seashore ecosystems is climate regulation and coastal protection, through carbon sequestration, waste treatment, and protection against hurricanes and the like.” [1].

[1]. Julio Godoy, “Climate change target too ambitious, say lawmakers”, IPS, 26 October 2009: http://www.ipsnews.net/news.asp?idnews=49010 .

GLIKSON, Andrew. Dr Andrew Glikson (an Earth and paleo-climate research scientist at Australian National University, Canberra, Australia) (2009): “For some time now, climate scientists warned that melting of subpolar permafrost and warming of the Arctic Sea (up to 4 degrees C during 2005–2008 relative to the 1951–1980) are likely to result in the dissociation of methane hydrates and the release of this powerful greenhouse gas into the atmosphere (methane: 62 times the infrared warming effect of CO₂ over 20 years and 21 times over 100 years) … The amount of carbon stored in Arctic sediments and permafrost is estimated as 500–2500 Gigaton Carbon (GtC), as compared with the world’s total fossil fuel reserves estimated as 5000 GtC. Compare with the 700 GtC of the atmosphere, which regulate CO₂ levels in the range of 180–300 parts per million and land temperatures in a range of about – 50 to + 50 degrees C, which allowed the evolution of warm blooded mammals. The continuing use of the atmosphere as an open sewer for industrial pollution has already added some 305 GtC to the atmosphere together with land clearing and animal-emitted methane. This raised CO₂ levels to 387 ppm CO₂ to date, leading toward conditions which existed on Earth about 3 million years (Ma) ago (mid-Pliocene), when CO₂ levels rose to about 400 ppm, temperatures to about 2–3 degrees C and sea levels by about 25 +/- 12 metres. There is little evidence for an extinction at 3 Ma. However, by crossing above a CO₂ level of 400 ppm the atmosphere is moving into uncharted territory. At this stage, enhanced methane leaks threaten climate events, such as the massive methane release and fauna extinction of 55 million years ago, which was marked by rise of CO₂ to near-1000 ppm.” [1].

Part of a statement prepared by Dr Barrie Pittock PSM (former leader, Climate Impact Group, CSIRO, IPCC Lead Author, and author of Climate Change: Turning Up the Heat), and Dr Andrew Glikson(Earth and paleoclimate research scientist, former Principal Research Scientist, AGSO; Visiting Fellow, Australian National University), and endorsed by 40 leading Australian environment scientists: “Australia to make every effort through its own and international actions to prevent CO2 -- equivalent levels from rising above 450 ppm and global warming from rising above 2 degrees C relative to pre-industrial temperatures, as is the European target. Further reduction of CO₂ levels to 300-350 ppm may be required to have a reasonable probability of restoring a safe climate.” [2].

[1]. Dr Andrew Glikson, “The Methane Time Bomb and the Triple Melt-down", Countercurrents, 2009 : http://www.countercurrents.org/glikson101008.htm .

[2]. 350.org, “40 Australian scientists sign on to 350 target, call for urgency in the fight against climate change”, 22 October 2008: http://www.350.org/en/about/blogs/40-australian-scientists-sign-350-target-call-urgency-fight-against-climate-change .

GOREAU, T. Dr T. Goreau (Jamaica delegation climate change expert making a scientific and technical briefing to the Association of Small Island States, UN Climate Change Conference, Copenhagen, Denmark, December 7-18, 2009): “Summary. The long-term sea level that corresponds to current CO2 concentration is about 23 meters above today’s levels, and the temperatures will be 6 degrees C higher. These estimates are based on real, long term climate records, not on models. We have not yet felt the real impacts of the current excess of greenhouse gases produced by fossil fuels, and the data shows that they will in the long run be many times higher than IPCC models project. In order to prevent these long term changes, CO2 must be stabilized at levels below preindustrial levels, around 260 parts per million. CO2 build up must be reversed, not allowed to increase or even to be stabilized at 350 ppm, which would amount to a death sentence for coral reefs, small island developing states, and billions of people living along low lying coast lines. The good news is that all tools for reversing global warming and reducing CO2 to safe levels are ready, proven, and cost effective, but are not being seriously used due to lack of polices and funding.” [1].

[1]. Dr T. Goreau, “What is the right target for CO2? 350 ppm is a death sentence for coral reefs and low lying islands, the safe level for SIDS [Small Island Developing States] is around 260 parts per million [ppm]”, scientific and technical briefing to the Association of Small Island States, UN Climate Change Conference, Copenhagen, Denmark, December 7-18, 2009: http://www.globalcoral.org/wpcontent/uploads/2014/01/aosis_briefing_2009.pdf .

HANSEN, James. Dr James Hansen (top US climate scientist; former Director, NASA Goddard Institute for Space Studies; member of the prestigious US National Academy of Sciences; 2007 Award for Scientific Freedom and Responsibility of the prestigious American Association for the Advancement of Science; Adjunct Professor, Columbia University, New York, USA) et al. (2008): “Stabilization of Arctic sea ice cover requires, to first approximation, restoration of planetary energy balance. Climate models driven by known forcings yield a present planetary energy imbalance of +0.5-1 W/m2. Observed heat increase in the upper 700 m of the ocean confirms the planetary energy imbalance, but observations of the entire ocean are needed for quantification. CO₂ amount must be reduced to 325-355 ppm to increase outgoing flux 0.5-1 W/m2, if other forcings are unchanged. A further imbalance reduction, and thus CO₂ ~300-325 ppm, may be needed to restore sea ice to its area of 25 years ago.” [1].

Statement by the World's top climate scientists including Professors James Hansen (US), Hans Joachim Schellnhuber (Germany) , Paul Crutzen (Netherlands Nobel Laureate), in the top scientific journal Nature that atmospheric CO2 must NOT exceed 350 ppm (September 2009): "Our proposed climate boundary is based on two critical thresholds that separate qualitatively different climate-system states. It has two parameters: atmospheric concentration of carbon dioxide and radiative forcing (the rate of energy change per unit area of the globe as measured at the top of the atmosphere). We propose that human changes to atmospheric CO₂ concentrations should not exceed 350 parts per million by volume, and that radiative forcing should not exceed 1 watt per square metre above pre-industrial levels. Transgressing these boundaries will increase the risk of irreversible climate change, such as the loss of major ice sheets, accelerated sea-level rise and abrupt shifts in forest and agricultural systems. Current CO₂ concentration stands at 387 p.p.m.v. and the change in radiative forcing is 1.5 W m^-2 . " [2].

James Hansen, Pushker Kharecha, Makiko Sato, Valerie Masson-Delmotte, Frank Ackerman, David J. Beerling, Paul J. Hearty, Ove Hoegh-Guldberg, Shi-Ling Hsu, Camille Parmesan, Johan Rockstrom, Eelco J. Rohling, Jeffrey Sachs, Pete Smith, Konrad Steffen, Lise Van Susteren, Karina von Schuckmann, James C. Zachos (2013): "Earth’s energy imbalance is the most vital number characterizing the state of Earth’s climate. It informs us about the global temperature change “in the pipeline” without further change of climate forcings and it defines how much greenhouse gases must be reduced to restore Earth’s energy balance, which, at least to a good approximation, must be the requirement for stabilizing global climate. The measured energy imbalance accounts for all natural and human-made climate forcings, including changes of atmospheric aerosols and Earth’s surface albedo.

If Earth’s mean energy imbalance today is +0.5 W/m², CO₂ must be reduced from the current level of 395 ppm (global-mean annual-mean in mid-2013) to about 360 ppm to increase Earth’s heat radiation to space by 0.5 W/m² and restore energy balance. If Earth’s energy imbalance is 0.75 W/m², CO₂ must be reduced to about 345 ppm to restore energy balance [64], [75].

The measured energy imbalance indicates that an initial CO₂ target “<350 ppm” would be appropriate, if the aim is to stabilize climate without further global warming. That target is consistent with an earlier analysis [54]. Additional support for that target is provided by our analyses of ongoing climate change and paleoclimate, in later parts of our paper. Specification now of a CO₂ target more precise than <350 ppm is difficult and unnecessary, because of uncertain future changes of forcings including other gases, aerosols and surface albedo. More precise assessments will become available during the time that it takes to turn around CO₂ growth and approach the initial 350 ppm target." [3].

[1]. Hansen, J., Mki. Sato, P. Kharecha, D. Beerling, R. Berner, V. Masson-Delmotte, M. Pagani, M. Raymo, D.L. Royer, and J.C. Zachos, 2008: Target atmospheric CO₂: Where should humanity aim? Open Atmos. Sci. J., 2, 217-231: http://pubs.giss.nasa.gov/abstracts/2008/Hansen_etal.html (abstract) and http://pubs.giss.nasa.gov/docs/2008/2008_Hansen_etal.pdf .

[2]. Johan Rockström, Will Steffen, Kevin Noone, Åsa Persson, F. Stuart Chapin, III, Eric F. Lambin, Timothy M. Lenton, Marten Scheffer, Carl Folke, Hans Joachim Schellnhuber, Björn Nykvist, Cynthia A. de Wit, Terry Hughes, Sander van der Leeuw, Henning Rodhe, Sverker Sörlin, Peter K. Snyder, Robert Costanza, Uno Svedin, Malin Falkenmark, Louise Karlberg, Robert W. Corell, Victoria J. Fabry, James Hansen, Brian Walker, Diana Liverman, Katherine Richardson, Paul Crutzen & Jonathan A. Foley, “A safe operating space for humanity”, Nature, 461, 472-475, 2009: http://www.nature.com/nature/journal/v461/n7263/full/461472a.html .

[3]. James Hansen, Pushker Kharecha, Makiko Sato, Valerie Masson-Delmotte, Frank Ackerman, David J. Beerling, Paul J. Hearty, Ove Hoegh-Guldberg, Shi-Ling Hsu, Camille Parmesan, Johan Rockstrom, Eelco J. Rohling, Jeffrey Sachs, Pete Smith, Konrad Steffen, Lise Van Susteren, Karina von Schuckmann, James C. Zachos, “Assessing “dangerous climate change”: required reduction of carbon emissions to protect young people, future generations and Nature”, PLOS One, 8 (12), 3 December 2013: http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0081648 .

James Hansen on the Earth’s energy imbalance and the need for negative CO2 emissions to 342-373 ppm CO2 (2018): “Earth is now substantially out of energy balance. The amount of solar energy that Earth absorbs exceeds the energy radiated back to space. The principal manifestations of this energy imbalance are continued global warming on decadal time scales and continued increase in ocean heat content. Quantitative understanding of Earth’s energy imbalance has improved over the past decade. The upper two kilometers of the ocean, where most of the excess energy is stored, has been well-monitored by the international Argo floats program since 2005. Over the full solar cycle 2005-2016 Earth’s energy imbalance is 0.75 ± 0.25 W/m2 . The range 0.5 to 1 W/m2 is substantial. For example, in order to restore Earth’s energy balance by reducing atmospheric CO2, which is the principal cause of the imbalance, CO2 would need to be reduced from its 2018 407 amount to 373 ppm if the imbalance is 0.50 W/m2, but to 342 ppm if the imbalance is 1 W/m2 . In reality CO2 is not only continuing to increase, its rate of growth is increasing. The reason is that global population and energy demands continue to increase, and about 85 percent of global energy is provided by fossil fuels…

sea level reached heights as great as 6-9 meters during the prior interglacial period, the Eemian about 120,000 years ago, when global temperature was only about 1°C above the pre-industrial level, i.e., similar to today’s global temperature. During the early Pliocene, several million years ago, when global temperature was at most about 3°C warmer than pre-industrial conditions, sea level probably reached as high as 15-25 meters above today’s level. In other words, there is plenty of vulnerable ice available to cause eventual sea level rise that would inundate today’s coastal cities, in response to a warming level that we could produce this century. Burning all of the readily available fossil fuels would eventually melt almost all the ice on the planet, raising sea level 65-75 meters (more than 300 feet)…

How much CO2 must be extracted from the air today to offset the excess growth of greenhouse gas forcing in a single year, i.e., to reduce climate forcing by 0.015 W/m2? Atmospheric CO2 must be reduced almost exactly 1 ppm CO2 to increase heat radiation to space by 0.015 W/m2. [We actually need to suck more than 1 ppm from the air, because the ocean reacts to the reduction of atmospheric CO2 by increasing the net backflux of CO2 to the atmosphere. However, we can make our point without including this added difficulty in achieving CO2 drawdown.] One ppm of CO2 is 2.12 billion tons of carbon or about 7.77 billion tons of CO2. Recently Keith et al.(2018) achieved a cost breakthrough in carbon capture, demonstrated with a pilot plant in Canada. Cost of carbon capture, not including the cost of transportation and storage of the CO2, is $113-232 per ton of CO2. Thus the cost of extracting 1 ppm of CO2 from the atmosphere is $878-1803 billion” (James Hansen, “Climate change in a nutshell: the gathering storm”, Columbia University, 18 December 2018: http://www.columbia.edu/~jeh1/mailings/2018/20181206_Nutshell.pdf [55 pages]).

HOEGH-GULDBERG, Ove. Professor Ove Hoegh-Guldberg (University of Queensland), Dr Mary Stafford-Smith (Coral Reef Research), Professor John Veron (Coral Reef Research), and 20 other eminent scientists (2009): "The Earth’s atmospheric CO₂ level must be returned to less than 350ppm to reverse this escalating ecological crisis and to 320ppm to ensure permanent planetary health. Actions to achieve this must be taken urgently. The commonly mooted best case target of 450ppm and a time frame reaching to 2050 will plunge the Earth into an environmental state that has not occurred in millions of years and from which there will be no recovery for coral reefs and for many other natural systems on which humanity depends. Working group signatories Professor John Veron (Coral Reef Research), Dr Mary Stafford-Smith (Coral Reef Research), Prof. Ove Hoegh-Guldberg (University of Queensland) [and 20 other eminent scientists]". [1].

James Hansen, Pushker Kharecha, Makiko Sato, Valerie Masson-Delmotte, Frank Ackerman, David J. Beerling, Paul J. Hearty, Ove Hoegh-Guldberg, Shi-Ling Hsu, Camille Parmesan, Johan Rockstrom, Eelco J. Rohling, Jeffrey Sachs, Pete Smith, Konrad Steffen, Lise Van Susteren, Karina von Schuckmann, James C. Zachos (2013): "Earth’s energy imbalance is the most vital number characterizing the state of Earth’s climate. It informs us about the global temperature change “in the pipeline” without further change of climate forcings and it defines how much greenhouse gases must be reduced to restore Earth’s energy balance, which, at least to a good approximation, must be the requirement for stabilizing global climate. The measured energy imbalance accounts for all natural and human-made climate forcings, including changes of atmospheric aerosols and Earth’s surface albedo.

If Earth’s mean energy imbalance today is +0.5 W/m², CO₂ must be reduced from the current level of 395 ppm (global-mean annual-mean in mid-2013) to about 360 ppm to increase Earth’s heat radiation to space by 0.5 W/m² and restore energy balance. If Earth’s energy imbalance is 0.75 W/m², CO₂ must be reduced to about 345 ppm to restore energy balance [64], [75].

The measured energy imbalance indicates that an initial CO₂ target “<350 ppm” would be appropriate, if the aim is to stabilize climate without further global warming. That target is consistent with an earlier analysis [54]. Additional support for that target is provided by our analyses of ongoing climate change and paleoclimate, in later parts of our paper. Specification now of a CO₂ target more precise than <350 ppm is difficult and unnecessary, because of uncertain future changes of forcings including other gases, aerosols and surface albedo. More precise assessments will become available during the time that it takes to turn around CO₂ growth and approach the initial 350 ppm target." [2].

[1]. Output of the technical working group meeting, The Royal Society, London, 6th July, 2009, “The Coral Reef Crisis: scientific justification for critical CO₂ threshold levels of less than 350ppm”: http://www.carbonequity.info/PDFs/The-Coral-Reef-Crisis.pdf .

[2]. James Hansen, Pushker Kharecha, Makiko Sato, Valerie Masson-Delmotte, Frank Ackerman, David J. Beerling, Paul J. Hearty, Ove Hoegh-Guldberg, Shi-Ling Hsu, Camille Parmesan, Johan Rockstrom, Eelco J. Rohling, Jeffrey Sachs, Pete Smith, Konrad Steffen, Lise Van Susteren, Karina von Schuckmann, James C. Zachos, “Assessing “dangerous climate change”: required reduction of carbon emissions to protect young people, future generations and Nature”, PLOS One, 8 (12), 3 December 2013: http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0081648 .

JOUGHIN, Ian . Dr Ian Joughin, a glaciologist at the University of Washington (UW), Seattle, Washinton, USA, and lead author of a key paper on the West Antarctica ice sheet collapse, of which the early-stage collapse is already underway (2014): “Abstract. Resting atop a deep marine basin, the West Antarctic Ice Sheet has long been considered prone to instability. Using a numerical model, we investigated the sensitivity of Thwaites Glacier to ocean melt and whether its unstable retreat is already under way. Our model reproduces observed losses when forced with ocean melt comparable to estimates. Simulated losses are moderate (<0.25 mm per year at sea level) over the 21st century but generally increase thereafter. Except possibly for the lowest-melt scenario, the simulations indicate that early-stage collapse has begun. Less certain is the time scale, with the onset of rapid (>1 mm per year of sea-level rise) collapse in the different simulations within the range of 200 to 900 years.” [1].

[Editor’s note: Core samples indicate that seawater has filled the West Antarctic basins within the past 750,000 years. The atmospheric CO2 has been between 180 and 280 ppm for the last 800,000 years but has increased since the start of the Industrial revolution and is now about 400 ppm and increasing at a record 2.5 ppm per year and energy-linked CO2 pollution is remorselessly increasing (see “300.org – return atmosphere CO2 to 300 ppm”, 300.org: http://sites.google.com/site/300orgsite/300-org---return-atmosphere-co2-to-300-ppm ; US EIA, “Energy-related carbon dioxide emissions”, Table A10: http://www.eia.gov/forecasts/ieo/emissions.cfm ; US National Oceanic and Atmospheric Administration (NOAA) Mauna Loa Observatory, “Trends in Atmospheric Carbon Dioxide”: http://www.esrl.noaa.gov/gmd/ccgg/trends/ ].

[1]. Ian Joughin, Benjamin E. Smith, Brooke Medley, “Marine ice sheet collapse potentially under way for the Thwaites Glacier Basin West Antarctica”, Science 16 May 2014, Vol. 344 no. 6185 pp. 735-738: http://www.sciencemag.org/content/344/6185/735.abstract .

MCKIBBEN, Bill. Bill McKibben (founder, 350.org, that espouses 24 October, UN Day, as also 350 Day for international action of global warming), 23 October 2009: “Physics and chemistry have already announced their bottom line. In the last two years a slew of research has shown that the most carbon we can safely have in the atmosphere is 350 parts per million - indeed, a NASA team said that above that figure we can’t have “a planet similar to the one on which civilization developed or to which life on earth is adapted.’’ We’re already well past the 350 figure, at 390 parts per million, which is why Arctic sea ice is melting, glaciers thawing, and the ocean turning steadily more acidic. To meet the 350 goal will mean a far more aggressive approach than the one Obama and Congress have so far taken (the bill making its way through Congress explicitly aims for a world with 450 parts per million carbon).” [1].

Bill McKibben on 3 critical climate change numbers 2, 565 and 2,795 (2012) [I have inserted the appropriate UNITS that are crucial to the argument] : “2 [degrees Centigrade] … So far, we've raised the average temperature of the planet just under 0.8 degrees Celsius, and that has caused far more damage than most scientists expected. (A third of summer sea ice in the Arctic is gone, the oceans are 30 percent more acidic, and since warm air holds more water vapor than cold, the atmosphere over the oceans is a shocking five percent wetter, loading the dice for devastating floods.) Given those impacts, in fact, many scientists have come to think that two degrees is far too lenient a target. "Any number much above one degree involves a gamble," writes Kerry Emanuel of MIT, a leading authority on hurricanes, "and the odds become less and less favorable as the temperature goes up." Thomas Lovejoy, once the World Bank's chief biodiversity adviser, puts it like this: "If we're seeing what we're seeing today at 0.8 degrees Celsius, two degrees is simply too much." NASA scientist James Hansen, the planet's most prominent climatologist, is even blunter: "The target that has been talked about in international negotiations for two degrees of warming is actually a prescription for long-term disaster". At the Copenhagen summit, a spokesman for small island nations warned that many would not survive a two-degree rise: "Some countries will flat-out disappear." When delegates from developing nations were warned that two degrees would represent a "suicide pact" for drought-stricken Africa, many of them started chanting, "One degree, one Africa."Despite such well-founded misgivings, political realism bested scientific data, and the world settled on the two-degree target – indeed, it's fair to say that it's the only thing about climate change the world has settled on. All told, 167 countries responsible for more than 87 percent of the world's carbon emissions have signed on to the Copenhagen Accord, endorsing the two-degree target. Only a few dozen countries have rejected it, including Kuwait, Nicaragua and Venezuela. Even the United Arab Emirates, which makes most of its money exporting oil and gas, signed on. The official position of planet Earth at the moment is that we can't raise the temperature more than two degrees Celsius – it's become the bottomest of bottom lines. Two degrees…565 [billion tonnes CO2]… scientists estimate that humans can pour roughly 565 more gigatons of carbon dioxide into the atmosphere by midcentury and still have some reasonable hope of staying below two degrees. ("Reasonable," in this case, means four chances in five, or somewhat worse odds than playing Russian roulette with a six-shooter.) This idea of a global "carbon budget" emerged about a decade ago, as scientists began to calculate how much oil, coal and gas could still safely be burned. Since we've increased the Earth's temperature by 0.8 degrees so far, we're currently less than halfway to the target… 2,795 [billion tonnes CO2] The number describes the amount of carbon already contained in the proven coal and oil and gas reserves of the fossil-fuel companies, and the countries (think Venezuela or Kuwait) that act like fossil-fuel companies. In short, it's the fossil fuel we're currently planning to burn. And the key point is that this new number – 2,795 – is higher than 565. Five times higher.” [2].

[1]. Bill McKibben, “Mr. Obama, be tough on climate change”, The Boston Globe, 23 October 2009: http://www.boston.com/bostonglobe/editorial_opinion/oped/articles/2009/10/23/mr_obama_be_tough_on_climate_change/ .

[2]. Bill McKibben , “Global warming’s terrifying New Math. Three simple numbers that add up to global catastrophe - and that make clear who the real enemy is”, Rolling Stone, 19 July 2012: http://www.rollingstone.com/politics/news/global-warmings-terrifying-new-math-20120719 .

MORNINGSTAR, Cory. Cory Morningstar (Canadians for Action on Climate) and Joan Russow PhD (Global Compliance Research Project) (2010): "Before COP15, during COP15 and POST COP15, there has been a global 350.org campaign. At COP15, states such as Bolivia, and the ALBA group, and some scientists and activists were calling for parts per million (ppm) of carbon dioxide to return to 300 ppm. When people from the 350.org campaign were asked why they did not respond to the lower demands, their response was ‘350.org is our campaign’. However, more and more leading climate activists and leading world scientists are advocating the necessity of returning to 300 ppm." [1].

[1]. Joan Russow and Cory Morningstar, "Climate change: a global imperative to return to 300 ppm", Canadians For Action on Climate Change", 9 April 2010: http://canadianclimateaction.wordpress.com/writings-2009-2010/climate-change-a-global-imperative-to-return-to-300-ppm/ .

MORRIGAN, Tariel. Tariel Mórrígan (Principal Research Associate, Global Climate Change, Human Security and Democracy, Global & International Studies, University of California, Santa Barbara, California, USA) (2010 ): “ Limiting the atmospheric CO2 concentration to no greater than 350 ppm might prevent committed global warming to no more than 2.4oC in the long term, after the temporary delay by climate and ocean thermal inertia reach their peak potenttial climate forcing (i.e. warming) , Stabilization at or below 350 ppm CO2-eq provides a 93% probability of staying below 2oC above pre-industrial values (IPCC, 2007c ; Meinshausen, 2006). Thjerefore a CO2 target as low as 300 ppm may be necessary to stabilize to prevent a dangerous warming of 2oC. Global average temperatures may stabilize within a likely range of 0.6-1.4oC above pre-industrial values at or below 350 ppm CO2-eq (300 ppm CO2) (IPCC, 2007c ; Meinshausen, 2006).” [1].

[1]. Tariel Mórrígan, “Target atmospheric greenhouse gas concetrations. Why hunaity shoulkd aim for 350 ppm CO2-e”: http://www.global.ucsb.edu/climateproject/papers/pdf/Morrigan_2010_Target%20Atmospheric%20GHG%20Concentrations.pdf .

NASHEED, Mohammed. The president of the Maldive Islands, Mohammed Nasheed, and the Maldive Islands government (at an underwater Cabinet meeting), Resolution, October 2009: “With less than one degree of global warming, the glaciers are melting, the ice sheets collapsing, and low-lying areas are in danger of being swamped. We must unite in a global effort to halt further temperature rises, by slashing carbon dioxide emissions to a safe level of 350 parts per million.’’ [33].

PACHAURI, Rajendra. Nobel Peace Prize Laureate Dr Rajendra Pachauri ( U.N.'s top climate scientist, heading the Intergovernmental Panel on Climate Change , IPCC ) (August 2009) : "But as a human being I am fully supportive of that goal [below 350 ppm CO2]. What is happening, and what is likely to happen, convinces me ... [of] moving toward a 350 target". [1].

[1]. Bill McKibben, 350.org, "Pachauri's call for 350ppm is breakthrough moment for climate movement", UK Guardian, 26 August 2009:http://www.guardian.co.uk/environment/2009/aug/26/pachauri-350ppm-breakthrough-climate .

PEARMAN, Graeme. Dr Graeme Pearman (former CSIRO Climate director; GP Consulting; interim director, MSI; Monash University Sustainaibility Group, Melbourne): “The Earth is deglaciating. Since 1979, more than 20% of the Polar Ice Cap has melted away … Over the last century: global temperatures risen by 0.74 +/- 0.18^oC; 11 of last 12 years rank as amongst the 12 warmest years; snow cover decreased in most regions, especially in spring and summer; summer period extended 12.3 days … Arctic sea-ice decline of 2.7 +/- 0.6 per cent per decade; sea ;levels have risen at a rate of: 1961-2003 1.9 +/- 0.5 mm yr-1, 1900-2000 1.7 +/- 0.5 mm yr-1; ocean acidification 0.1 pH unit so far … Gases: current carbon dioxide and methane concentrations far exceed those of the last 600,000 years; increases primarily die to fossil fuel use, agriculture and land-use changes; Warming: unequivocal, evident in air and ocean temperatures, melting of snow and ice and rising sea levels; warming an effect of human activities – at least 5 times greater than that due to solar output change … extreme temperatures – more frequent, intense, longer-lived heat waves … Recent science strongly reinforces the views that: global warming is occurring; it is primarily a result of human activities." [1].

[1]. Dr Graeme Pearman, “Climate change: the evidence, science and current projections”, (2007): http://www.dpi.nsw.gov.au/__data/assets/pdf_file/0011/126569/graeme-pearman-monash-university-namoi-climate-change-forums.pdf .

PITTOCK, Barrie. Part of a statement prepared by Dr Barrie Pittock PSM (former leader, Climate Impact Group, CSIRO, IPCC Lead Author, and author of Climate Change: Turning Up the Heat), and Dr Andrew Glikson (Earth and paleoclimate research scientist, former Principal Research Scientist, AGSO; Visiting Fellow, Australian National University), and endorsed by 40 leading Australian environment scientists: “Australia to make every effort through its own and international actions to prevent CO2 -- equivalent levels from rising above 450 ppm and global warming from rising above 2 degrees C relative to pre-industrial temperatures, as is the European target. Further reduction of CO₂ levels to 300-350 ppm may be required to have a reasonable probability of restoring a safe climate.” [1].

[1]. 350.org, “40 Australian scientists sign on to 350 target, call for urgency oin the fight against climate change”, 22 October 2008: http://www.350.org/en/about/blogs/40-australian-scientists-sign-350-target-call-urgency-fight-against-climate-change .

POLYA, Gideon. Dr Gideon Polya (Convenor, 300.org, that argues for a return to ~300 ppm CO2), 24 October 2009: "Dear Sir/Madam,

24 October UN Day & 350 Day - Science says reduce CO2 to ~ 300 ppm.

Top climate scientists and the prestigious UK Royal Society say we must DECREASE atmospheric CO2 concentration from the present 390 ppm to 300-350 ppm ASAP for a safe planet for all peoples and all species. [1, 2].

Unfortunately, world governments and the pro-coal Australian Liberal-National Party Coalition Opposition and the pro-coal Australian Labor Federal Government (aka the Lib-Labs) want to INCREASE CO2 and other greenhouse gas (GHG) pollution. [3].

Australia is a world leader in per capita GHG pollution – having 0.3% of world population, its domestic and exported GHG pollution is 3% of world total. Yet optimistic interpretation of official Labor policy indicates that Australia’s domestic and exported GHG pollution will be 119% of the 2000 value by 2020 and 173% by 2050. [4].

The science-ignoring Australian Lib-Labs (US Rep-Dems) are betraying our children, the Great Barrier Reef, Australia, Humanity and the Biosphere of the Planet. Children should demand that their elders behave responsibly before it is too late and First World-imposed climate genocide destroys 10 billion non-Europeans this century, mostly children.". [5, 6].

Yours sincerely, Dr Gideon Polya

Convenor 300.org (see: http://sites.google.com/site/300orgsite/300-org ).

[1]. Johan Rockström, Will Steffen, Kevin Noone, Åsa Persson, F. Stuart Chapin, III, Eric F. Lambin, Timothy M. Lenton, Marten Scheffer, Carl Folke, Hans Joachim Schellnhuber, Björn Nykvist, Cynthia A. de Wit, Terry Hughes, Sander van der Leeuw, Henning Rodhe, Sverker Sörlin, Peter K. Snyder, Robert Costanza, Uno Svedin, Malin Falkenmark, Louise Karlberg, Robert W. Corell, Victoria J. Fabry, James Hansen, Brian Walker, Diana Liverman, Katherine Richardson, Paul Crutzen & Jonathan A. Foley, “A safe operating space for humanity”, Nature, 461, 472-475, 2009: http://www.nature.com/nature/journal/v461/n7263/full/461472a.html .

[2]. Output of the technical working group meeting, The Royal Society, London, 6th July, 2009, “The Coral Reef Crisis: scientific justification for critical CO2 threshold levels of less than 350ppm” [Working group signatories Professor John Veron (Coral Reef Research), Dr Mary Stafford-Smith (Coral Reef Research), Prof. Ove Hoegh-Guldberg (University of Queensland) and 20 other eminent scientists including Sir David Attenborough FRS (working group co-chair)]: http://www.carbonequity.info/PDFs/The-Coral-Reef-Crisis.pdf .

[3]. Gideon Polya, “G8 failure means climate genocide for Developing World”, Countercurrents, 11 July 2009: http://www.countercurrents.org/polya110709.htm .

[4]. Yarra Valley Climate Action Group, “Climate justice and climate injustice: Australia wants a 2020 per capita GHG pollution 15 times greater than Developing World’s”, 2009: http://sites.google.com/site/yarravalleyclimateactiongroup/climate-justice .

[5]. Gideon Polya, “School war crimes tribunals. Can children save the world’s children?”, MWC News, 8 October 2009: http://mwcnews.net/content/view/33643/42/ .

[6]. Dr Gideon Polya, “Message from Gideon Polya for 350 Day. 24 October UN Day & 350 Day- Science says reduce CO2 to ~ 300 ppm”, coalition for a Safe Climate, safeclimate.org: http://www.safeclimate.org.au/node/188 .

RIGNOT, Eric. Dr Eric Rignot, a glaciologist at NASA's Jet Propulsion Laboratory and lead author of a 2014 landmark scientific paper on West Antarctica revealing that the collapse of a large part of Antarctica is now unstoppable (2014): “Controlling climate warming may ultimately make a difference not only about how fast West Antarctic ice will melt to sea, but also whether other parts of Antarctica will take their turn. Several "candidates" are lined up, and we seem to have figured a way to push them out of equilibrium even before warming of air temperature is strong enough to melt snow and ice at the surface. Unabated climate warming of several degrees over the next century is likely to speed up the collapse of West Antarctica, but it could also trigger irreversible retreat of marine-based sectors of East Antarctica. Whether we should do something about it is simply a matter of common sense. And the time to act is now; Antarctica is not waiting for us.” [1; see also 2].

[Editor’s note: Core samples indicate that seawater has filled the West Antarctic basins within the past 750,000 years. The atmospheric CO2 has been between 180 and 280 ppm for the last 800,000 years but has increased since the start of the Industrial revolution and is now about 400 ppm and increasing at a record 2.5 ppm per year and energy-linked CO2 pollution is remorselessly increasing (see “300.org – return atmosphere CO2 to 300 ppm”, 300.org: http://sites.google.com/site/300orgsite/300-org---return-atmosphere-co2-to-300-ppm ; US EIA, “Energy-related carbon dioxide emissions”, Table A10: http://www.eia.gov/forecasts/ieo/emissions.cfm ; US National Oceanic and Atmospheric Administration (NOAA) Mauna Loa Observatory, “Trends in Atmospheric Carbon Dioxide”: http://www.esrl.noaa.gov/gmd/ccgg/trends/ ].

[1]. Eric Rignot, “Global warming: it’s a point of no return in West Antarctica. What happens next?”, The Observer, 18 May 2014: http://www.theguardian.com/commentisfree/2014/may/17/climate-change-antarctica-glaciers-melting-global-warming-nasa .

[2]. E. Rignot, J. Mouginot, M. Morlighem, H. Seroussi and B. Scheuchl, “Widespread, rapid grounding line retreat of Pine Island, Thwaites, Smith and Kohler glacier, West Antarctica from 1992 to 2011”, Geophysical Research Letters, 2014: http://onlinelibrary.wiley.com/doi/10.1002/2014GL060140/abstract .

ROCKSTROM, Johan. Statement by the World's top climate scientists including Professors Johan Rockström (executive director of the Stockholm Resilience Centre, natural resource management, Stockholm University), Paul Crutzen (Netherlands Nobel Laureate), James Hansen (US), Hans Joachim Schellnhuber (Germany), in the top scientific journal Nature that atmospheric CO2 must NOT exceed 350 ppm (September 2009): "Our proposed climate boundary is based on two critical thresholds that separate qualitatively different climate-system states. It has two parameters: atmospheric concentration of carbon dioxide and radiative forcing (the rate of energy change per unit area of the globe as measured at the top of the atmosphere). We propose that human changes to atmospheric CO₂ concentrations should not exceed 350 parts per million by volume, and that radiative forcing should not exceed 1 watt per square metre above pre-industrial levels. Transgressing these boundaries will increase the risk of irreversible climate change, such as the loss of major ice sheets, accelerated sea-level rise and abrupt shifts in forest and agricultural systems. Current CO₂ concentration stands at 387 p.p.m.v. and the change in radiative forcing is 1.5 W m^-2 . " [1].

James Hansen, Pushker Kharecha, Makiko Sato, Valerie Masson-Delmotte, Frank Ackerman, David J. Beerling, Paul J. Hearty, Ove Hoegh-Guldberg, Shi-Ling Hsu, Camille Parmesan, Johan Rockstrom, Eelco J. Rohling, Jeffrey Sachs, Pete Smith, Konrad Steffen, Lise Van Susteren, Karina von Schuckmann, James C. Zachos (2013): "Earth’s energy imbalance is the most vital number characterizing the state of Earth’s climate. It informs us about the global temperature change “in the pipeline” without further change of climate forcings and it defines how much greenhouse gases must be reduced to restore Earth’s energy balance, which, at least to a good approximation, must be the requirement for stabilizing global climate. The measured energy imbalance accounts for all natural and human-made climate forcings, including changes of atmospheric aerosols and Earth’s surface albedo.

If Earth’s mean energy imbalance today is +0.5 W/m², CO₂ must be reduced from the current level of 395 ppm (global-mean annual-mean in mid-2013) to about 360 ppm to increase Earth’s heat radiation to space by 0.5 W/m² and restore energy balance. If Earth’s energy imbalance is 0.75 W/m², CO₂ must be reduced to about 345 ppm to restore energy balance [64], [75].

The measured energy imbalance indicates that an initial CO₂ target “<350 ppm” would be appropriate, if the aim is to stabilize climate without further global warming. That target is consistent with an earlier analysis [54]. Additional support for that target is provided by our analyses of ongoing climate change and paleoclimate, in later parts of our paper. Specification now of a CO₂ target more precise than <350 ppm is difficult and unnecessary, because of uncertain future changes of forcings including other gases, aerosols and surface albedo. More precise assessments will become available during the time that it takes to turn around CO₂ growth and approach the initial 350 ppm target." [2].

[1]. Johan Rockström, Will Steffen, Kevin Noone, Åsa Persson, F. Stuart Chapin, III, Eric F. Lambin, Timothy M. Lenton, Marten Scheffer, Carl Folke, Hans Joachim Schellnhuber, Björn Nykvist, Cynthia A. de Wit, Terry Hughes, Sander van der Leeuw, Henning Rodhe, Sverker Sörlin, Peter K. Snyder, Robert Costanza, Uno Svedin, Malin Falkenmark, Louise Karlberg, Robert W. Corell, Victoria J. Fabry, James Hansen, Brian Walker, Diana Liverman, Katherine Richardson, Paul Crutzen & Jonathan A. Foley, “A safe operating space for humanity”, Nature, 461, 472-475, 2009: http://www.nature.com/nature/journal/v461/n7263/full/461472a.html .

[2]. James Hansen, Pushker Kharecha, Makiko Sato, Valerie Masson-Delmotte, Frank Ackerman, David J. Beerling, Paul J. Hearty, Ove Hoegh-Guldberg, Shi-Ling Hsu, Camille Parmesan, Johan Rockstrom, Eelco J. Rohling, Jeffrey Sachs, Pete Smith, Konrad Steffen, Lise Van Susteren, Karina von Schuckmann, James C. Zachos, “Assessing “dangerous climate change”: required reduction of carbon emissions to protect young people, future generations and Nature”, PLOS One, 8 (12), 3 December 2013: http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0081648 .

RUSSOW, Joan. Joan Russow PhD (Global Compliance Research Project) and Cory Morningstar (Canadians for Action on Climate) (2010): "Before COP15, during COP15 and POST COP15, there has been a global 350.org campaign. At COP15, states such as Bolivia, and the ALBA group, and some scientists and activists were calling for parts per million (ppm) of carbon dioxide to return to 300 ppm. When people from the 350.org campaign were asked why they did not respond to the lower demands, their response was ‘350.org is our campaign’. However, more and more leading climate activists and leading world scientists are advocating the necessity of returning to 300 ppm." [1].

[1]. Joan Russow and Cory Morningstar, "Climate change: a global imperative to return to 300 ppm", Canadians For Action on Climate Change", 9 April 2010: http://canadianclimateaction.wordpress.com/writings-2009-2010/climate-change-a-global-imperative-to-return-to-300-ppm/ .

SACHS, Jeffrey. James Hansen, Pushker Kharecha, Makiko Sato, Valerie Masson-Delmotte, Frank Ackerman, David J. Beerling, Paul J. Hearty, Ove Hoegh-Guldberg, Shi-Ling Hsu, Camille Parmesan, Johan Rockstrom, Eelco J. Rohling, Jeffrey Sachs, Pete Smith, Konrad Steffen, Lise Van Susteren, Karina von Schuckmann, James C. Zachos (2013): "Earth’s energy imbalance is the most vital number characterizing the state of Earth’s climate. It informs us about the global temperature change “in the pipeline” without further change of climate forcings and it defines how much greenhouse gases must be reduced to restore Earth’s energy balance, which, at least to a good approximation, must be the requirement for stabilizing global climate. The measured energy imbalance accounts for all natural and human-made climate forcings, including changes of atmospheric aerosols and Earth’s surface albedo.

If Earth’s mean energy imbalance today is +0.5 W/m², CO₂ must be reduced from the current level of 395 ppm (global-mean annual-mean in mid-2013) to about 360 ppm to increase Earth’s heat radiation to space by 0.5 W/m² and restore energy balance. If Earth’s energy imbalance is 0.75 W/m², CO₂ must be reduced to about 345 ppm to restore energy balance [64], [75].

The measured energy imbalance indicates that an initial CO₂ target “<350 ppm” would be appropriate, if the aim is to stabilize climate without further global warming. That target is consistent with an earlier analysis [54]. Additional support for that target is provided by our analyses of ongoing climate change and paleoclimate, in later parts of our paper. Specification now of a CO₂ target more precise than <350 ppm is difficult and unnecessary, because of uncertain future changes of forcings including other gases, aerosols and surface albedo. More precise assessments will become available during the time that it takes to turn around CO₂ growth and approach the initial 350 ppm target." [1].

[1]. James Hansen, Pushker Kharecha, Makiko Sato, Valerie Masson-Delmotte, Frank Ackerman, David J. Beerling, Paul J. Hearty, Ove Hoegh-Guldberg, Shi-Ling Hsu, Camille Parmesan, Johan Rockstrom, Eelco J. Rohling, Jeffrey Sachs, Pete Smith, Konrad Steffen, Lise Van Susteren, Karina von Schuckmann, James C. Zachos, “Assessing “dangerous climate change”: required reduction of carbon emissions to protect young people, future generations and Nature”, PLOS One, 8 (12), 3 December 2013: http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0081648 .

SCHELLNHUBER, Hans Joachim. Professor Hans Joachim Schellnhuber, director of the Potsdam Institute for Climate Impact Research., Germany (2008): “"It is a compromise between ambition and feasibility. A rise of 2^oC could avoid some of the big environmental disasters, but it is still only a compromise…It is a very sweeping argument, but nobody can say for sure that 330ppm is safe. Perhaps it will not matter whether we have 270ppm or 320ppm, but operating well outside the [historic] realm of carbon dioxide concentrations is risky as long as we have not fully understood the relevant feedback mechanisms" [280 ppm is the pre-industrial atmospheric CO₂ concentration]. [1].

Statement by the World's top climate scientists including Professors James Hansen (US), Hans Joachim Schellnhuber (Germany) , Paul Crutzen (Netherlands Nobel Laureate), in the top scientific journal Nature that atmospheric CO2 must NOT exceed 350 ppm (September 2009): "Our proposed climate boundary is based on two critical thresholds that separate qualitatively different climate-system states. It has two parameters: atmospheric concentration of carbon dioxide and radiative forcing (the rate of energy change per unit area of the globe as measured at the top of the atmosphere). We propose that human changes to atmospheric CO₂ concentrations should not exceed 350 parts per million by volume, and that radiative forcing should not exceed 1 watt per square metre above pre-industrial levels. Transgressing these boundaries will increase the risk of irreversible climate change, such as the loss of major ice sheets, accelerated sea-level rise and abrupt shifts in forest and agricultural systems. Current CO₂ concentration stands at 387 p.p.m.v. and the change in radiative forcing is 1.5 W m^-2 . " [2].

[1]. Professor Hans Joachim Schellnhuber quoted by David Adam, “Roll back time to safeguard climate, expert warns”, Guardian, 15 September 2008 : http://www.guardian.co.uk/environment/2008/sep/15/climatechange.carbonemissions .

[2]. Johan Rockström, Will Steffen, Kevin Noone, Åsa Persson, F. Stuart Chapin, III, Eric F. Lambin, Timothy M. Lenton, Marten Scheffer, Carl Folke, Hans Joachim Schellnhuber, Björn Nykvist, Cynthia A. de Wit, Terry Hughes, Sander van der Leeuw, Henning Rodhe, Sverker Sörlin, Peter K. Snyder, Robert Costanza, Uno Svedin, Malin Falkenmark, Louise Karlberg, Robert W. Corell, Victoria J. Fabry, James Hansen, Brian Walker, Diana Liverman, Katherine Richardson, Paul Crutzen & Jonathan A. Foley, “A safe operating space for humanity”, Nature, 461, 472-475, 2009: http://www.nature.com/nature/journal/v461/n7263/full/461472a.html .

SPRATT, David. David Spratt on the website called “Climate Code Red” (the title of a key book by David Spratt and Phillip Sutton) (2009): “The central point is that Arctic sea-ice is undergoing dramatic loss in summer, having lost 70-80% of its volume in the last 50 years, most since 2000. Without summer sea-ice, Greenland cannot escape a trajectory of ice-sheet loss leading to an eventual sea-level rise of 7 metres. Regional temperatures in the Arctic autumn are already up about 5C, and by mid-century an Arctic ice-free in summer, combined with more global warming, will be pushing Siberia close to the point where large-scale loss of carbon from melting permafrost would make further mitigation efforts futile. As Hansen told the US Congress in testimony last year, the “elements of a perfect storm, a global cataclysm, are assembled”. In short, if you don’t have a target that aims to cool the planet sufficiently to get the sea-ice back, the climate system may spiral out of control, past many “tipping points” to the final “point of no return”.

And that target is not 350ppm, it’s around 300 ppm. Hansen says Arctic sea-ice passed its tipping point decades ago, and in his presentations has also specifically identified 300-325ppm as the target range for sea-ice". [1].

[1]. David Spratt, “350 is the wrong target: put the science first”, Climate Code Red website, 22 January 2009: http://www.climatecodered.org/2009_01_01_archive.html .

STAFFORD-SMITH, Mary. Dr Mary Stafford-Smith (Coral Reef Research), Professor John Veron (Coral Reef Research), Prof. Ove Hoegh-Guldberg (University of Queensland) and 20 other eminent scientists 2009): "The Earth’s atmospheric CO₂ level must be returned to less than 350ppm to reverse this escalating ecological crisis and to 320ppm to ensure permanent planetary health. Actions to achieve this must be taken urgently. The commonly mooted best case target of 450ppm and a time frame reaching to 2050 will plunge the Earth into an environmental state that has not occurred in millions of years and from which there will be no recovery for coral reefs and for many other natural systems on which humanity depends. Working group signatories Professor John Veron (Coral Reef Research), Dr Mary Stafford-Smith (Coral Reef Research), Prof. Ove Hoegh-Guldberg (University of Queensland) [and 20 other eminent scientists]". [1].

[1]. Output of the technical working group meeting, The Royal Society, London, 6th July, 2009, “The Coral Reef Crisis: scientific justification for critical CO₂ threshold levels of less than 350ppm”: http://www.carbonequity.info/PDFs/The-Coral-Reef-Crisis.pdf .

STEFFEN, Will. Statement by the World's top climate scientists including Professors Will Steffen (ANU, Canberra, Australia), Paul Crutzen (Netherlands Nobel Laureate), James Hansen (US), Hans Joachim Schellnhuber (Germany), in the top scientific journal Nature that atmospheric CO2 must NOT exceed 350 ppm (September 2009): "Our proposed climate boundary is based on two critical thresholds that separate qualitatively different climate-system states. It has two parameters: atmospheric concentration of carbon dioxide and radiative forcing (the rate of energy change per unit area of the globe as measured at the top of the atmosphere). We propose that human changes to atmospheric CO₂ concentrations should not exceed 350 parts per million by volume, and that radiative forcing should not exceed 1 watt per square metre above pre-industrial levels. Transgressing these boundaries will increase the risk of irreversible climate change, such as the loss of major ice sheets, accelerated sea-level rise and abrupt shifts in forest and agricultural systems. Current CO₂ concentration stands at 387 p.p.m.v. and the change in radiative forcing is 1.5 W m^-2 . " [1].

[1]. Johan Rockström, Will Steffen, Kevin Noone, Åsa Persson, F. Stuart Chapin, III, Eric F. Lambin, Timothy M. Lenton, Marten Scheffer, Carl Folke, Hans Joachim Schellnhuber, Björn Nykvist, Cynthia A. de Wit, Terry Hughes, Sander van der Leeuw, Henning Rodhe, Sverker Sörlin, Peter K. Snyder, Robert Costanza, Uno Svedin, Malin Falkenmark, Louise Karlberg, Robert W. Corell, Victoria J. Fabry, James Hansen, Brian Walker, Diana Liverman, Katherine Richardson, Paul Crutzen & Jonathan A. Foley, “A safe operating space for humanity”, Nature, 461, 472-475, 2009: http://www.nature.com/nature/journal/v461/n7263/full/461472a.html .

STERN, Nicholas. Sir Nicholas Stern (top climate economist, IG Patel Professor of Economics and Government at the London School of Economics, former Chief Economist and Senior Vice-President of the World Bank from 2000 to 2003) (September 2009): “[Re 350 ppm CO2] I think it’s a very sensible long-term target…People have to be aware that is a truly long-term target. We have already passed 350ppm, we are at 390 ppm of CO2 and at 435 ppm of CO2-equivalents right now. It is most important to stop the increase of flows of emissions short term and then start the decline of flows of annual emissions and get them down to levels which will move concentrations of CO2 back down towards 350ppm.” [31].

[1]. Simon Leufstedt, “Nicholas Stern endorses 350 ppm as “a very sensible long-term target””, Green Blog, 12 September 2009: http://www.green-blog.org/2009/09/12/nicholas-stern-endorses-350-ppm-as-a-very-sensible-long-term-target/ .

SUMNER, Thomas. Thomas Sumner in Science Now (AAAS) on the slow collapse of the West Antarctic ice sheet (2014): “A disaster may be unfolding—in slow motion. Earlier this week, two teams of scientists reported that the Thwaites Glacier, a keystone holding the massive West Antarctic Ice Sheet together, is starting to collapse. In the long run, they say, the entire ice sheet is doomed, which would release enough meltwater to raise sea levels by more than 3 meters. One team combined data on the recent retreat of the 182,000-square-kilometer Thwaites Glacier with a model of the glacier’s dynamics to forecast its future. In a paper published online today in Science, they report that in as few as 2 centuries Thwaites Glacier’s outermost edge will recede past an underwater ridge now stalling its retreat. Their modeling suggests that the glacier will then cascade into rapid collapse. The second team, writing in Geophysical Research Letters (GRL), describes recent radar mapping of West Antarctica’s glaciers and confirms that the 600-meter-deep ridge is the final obstacle before the bedrock underlying the glacier dips into a deep basin. Because inland basins connect Thwaites Glacier to other major glaciers in the region, both research teams say its collapse would flood West Antarctica with seawater, prompting a near-complete loss of ice in the area... Core samples drilled into the inland basins that connect Thwaites Glacier with its neighbors have revealed algae preserved beneath the ice sheet, a hint that seawater has filled the basins within the past 750,000 years. That past flooding shows that modest climate warming can cause the entire ice sheet to collapse.” [1].

[Editor’s note: The atmospheric CO2 has been between 180 and 280 ppm for the last 800,000 years but has increased since the start of the Industrial revolution and is now about 400 ppm and increasing at a record 2.5 ppm per year and energy-linked CO2 pollution is remorselessly increasing (see “300.org – return atmosphere CO2 to 300 ppm”, 300.org: http://sites.google.com/site/300orgsite/300-org---return-atmosphere-co2-to-300-ppm ; US EIA, “Energy-related carbon dioxide emissions”, Table A10: http://www.eia.gov/forecasts/ieo/emissions.cfm ; US National Oceanic and Atmospheric Administration (NOAA) Mauna Loa Observatory, “Trends in Atmospheric Carbon Dioxide”: http://www.esrl.noaa.gov/gmd/ccgg/trends/ ].

[1]. Thomas Sumner, “West Antarctic ice sheet is collapsing”, Science Now, 12 May 2014: http://news.sciencemag.org/climate/2014/05/west-antarctic-ice-sheet-collapsing .

VERON, John. Professor John Veron (Coral Reef Research), Dr Mary Stafford-Smith (Coral Reef Research), Prof. Ove Hoegh-Guldberg (University of Queensland) and 20 other eminent scientists 2009): "The Earth’s atmospheric CO₂ level must be returned to less than 350ppm to reverse this escalating ecological crisis and to 320ppm to ensure permanent planetary health. Actions to achieve this must be taken urgently. The commonly mooted best case target of 450ppm and a time frame reaching to 2050 will plunge the Earth into an environmental state that has not occurred in millions of years and from which there will be no recovery for coral reefs and for many other natural systems on which humanity depends. Working group signatories Professor John Veron (Coral Reef Research), Dr Mary Stafford-Smith (Coral Reef Research),Prof. Ove Hoegh-Guldberg (University of Queensland) [and 20 other eminent scientists]". [1].

J.E.N. Veron, O. Hoegh-Guldberg, T.M. Lenton, J.M. Lough, D.O. Obura, P. Pearce-Kelly, C.R.C. Sheppard, M. Spalding, M.G. Stafford-Smith and A.D. Rogers (top coral scientists) (2009), “The coral reef crisis: the critical importance of <350 ppm CO2”, Marine Pollution Bulletin, October 2009: “Temperature-induced mass coral bleaching causing mortality on a wide geographic scale started when atmospheric CO₂ levels exceeded 320 ppm. When CO₂ levels reached 340 ppm, sporadic but highly destructive mass bleaching occurred in most reefs world-wide, often associated with El Niño events. Recovery was dependent on the vulnerability of individual reef areas and on the reef’s previous history and resilience. At today’s level of 387 ppm, allowing a lag-time of 10 years for sea temperatures to respond, most reefs world-wide are committed to an irreversible decline. Mass bleaching will in future become annual, departing from the 4 to 7 years return-time of El Niño events. Bleaching will be exacerbated by the effects of degraded water-quality and increased severe weather events. In addition, the progressive onset of ocean acidification will cause reduction of coral growth and retardation of the growth of high magnesium calcite-secreting coralline algae.” [2].

[1]. Output of the technical working group meeting, The Royal Society, London, 6th July, 2009, “The Coral Reef Crisis: scientific justification for critical CO₂ threshold levels of less than 350ppm”: http://www.carbonequity.info/PDFs/The-Coral-Reef-Crisis.pdf .

[2]. J.E.N. Veron, O. Hoegh-Guldberg, T.M. Lenton, J.M. Lough, D.O. Obura, P. Pearce-Kelly, C.R.C. Sheppard, M. Spalding, M.G. Stafford-Smith and A.D. Rogers, “The coral reef crisis: the critical importance of <350 ppm CO2”, Marine Pollution Bulletin, vol. 58, (10), October 2009, 1428-1436: http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V6N-4X9NKG7-3&_user=10&_rdoc=1&_fmt=&_orig=search&_sort=d&_docanchor=&view=c&_searchStrId=1072337698&_rerunOrigin=google&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=6858c5ff7172f9355068393496a5b35d .

WADHAMS, Peter. Peter Wadhams is professor of Ocean Physics, and Head of the Polar Ocean Physics Group in the Department of Applied Mathematics and Theoretical Physics, University of Cambridge, UK. He is best known for his work on sea ice and for his early warnings in 1990 about the thinning of Arctic summer sea ice. Professor Wadhams is the president of the International Association for the Physical Sciences of the Ocean Commission on Sea Ice and Co-ordinator for the International Programme for Antarctic Buoys (see: http://en.wikipedia.org/wiki/Peter_Wadhams ).

Professor Peter Wadhams on the record loss of Arctic sea ice and the impending loss of all Arctic summer sea ice by 2015 (2012): “The entire ice cover is now on the point of collapse. The extra open water already created by the retreating ice allows bigger waves to be generated by storms, which are sweeping away the surviving ice. It is truly the case that it will be all gone by 2015. The consequences are enormous and represent a huge boost to global warming.” [1].

Peter Wadhams and colleagues on the threat of 50Gt methane from East Siberian Arctic Shelf: (2013): “Economic time bomb. As the amount of Arctic sea ice declines at an unprecedented rate, the thawing of offshore permafrost releases methane. A 50-gigatonne (Gt) reservoir of methane, stored in the form of hydrates, exists on the East Siberian Arctic Shelf. It is likely to be emitted as the seabed warms, either steadily over 50 years or suddenly. Higher methane concentrations in the atmosphere will accelerate global warming and hasten local changes in the Arctic, speeding up sea-ice retreat, reducing the reflection of solar energy and accelerating the melting of the Greenland ice sheet. The ramifications will be felt far from the poles… To quantify the effects of Arctic methane release on the global economy, we used PAGE09. This integrated assessment model calculates the impacts of climate change and the costs of mitigation and adaptation measures… The methane pulse will bring forward by 15–35 years the average date at which the global mean temperature rise exceeds 2°C above pre-industrial levels — to 2035 for the business-as-usual scenario and to 2040 for the low-emissions case (see 'Arctic methane'). This will lead to an extra $60 trillion (net present value) of mean climate-change impacts for the scenario with no mitigation, or 15% of the mean total predicted cost of climate-change impacts (about $400 trillion)." [2].

[Editor’s note: The Global Warming Potential (GWP) of CH4 on a 20 year time frame and with aerosol impacts considered is 105 times that of CO2 [3, 4]. The German WBGU (2009) and the Australian Climate Commission (2013) have estimated that no more than 600 billion tonnes of CO2 can be emitted between 2010 and zero emissions in 2050 if the world is to have a 75% chance of avoiding a catastrophic 2C temperature rise [5, 6]. The 50 Gt (billion tonnes) CH4 in the East Siberian Arctic Shelf is thus equivalent to 50 billion tonnes CH4 x 105 tonnes CO2-equivalent/tonne CH4 = 5,250 tonnes CO2-e or about NINE(9) times more than the world’s terminal greenhouse gas (GHG) pollution budget. We are doomed unless we can stop this Arctic CH4 release].

[1]. Professor Peter Wadhams quoted in Julia Horton, “Arctic sea ice will vanish within three years, says expert ”, Scotsman, 29 August 2012: http://www.scotsman.com/news/environment/arctic-sea-ice-will-vanish-within-three-years-says-expert-1-2493681 .

[2]. Gail Whiteman, Chris Hope and Peter Wadhams, “Vast costs of Arctic change”, Nature, 499, 25 July 2013: http://www.nature.com/nature/journal/v499/n7459/pdf/499401a.pdf and http://www.nature.com/nature/journal/v499/n7459/full/499401a.html .

[3]. Drew T. Shindell , Greg Faluvegi, Dorothy M. Koch , Gavin A. Schmidt , Nadine Unger and Susanne E. Bauer , “Improved Attribution of Climate Forcing to Emissions”, Science, 30 October 2009:

Vol. 326 no. 5953 pp. 716-718: http://www.sciencemag.org/content/326/5953/716 .

[4]. Shindell et al (2009), Fig.2: http://www.sciencemag.org/content/326/5953/716.figures-only .

[5]. WBGU, “Solving the climate dilemma: the budget approach”: http://www.ecoequity.org/2009/10/solving-the-climate-dilemma-the-budget-approach/ .

[6]. Australian Climate Commission, “The critical decade 2013: a summary of climate change science, risks and responses”, 2013, p7: http://climatecommission.gov.au/wp-content/uploads/The-Critical-Decade-2013-Summary_lowres.pdf .

(B) ORGANIZATIONS

300.ORG. 300.org (that exists to inform people about the Climate Emergency and the need to reduce atmospheric CO₂ concentration to a safe and sustainable level of about 300 ppm: “There must be a safe and sustainable existence for all peoples and all species on our warming-threatened Planet and this requires a rapid reduction of atmospheric carbon dioxide concentration to about 300 parts per million”. [1, 2, 3].

[1]. "300.org": https://sites.google.com/site/300orgsite/300-org .

[2]. “300.org – return atmosphere to 300 ppm”; https://sites.google.com/site/300orgsite/300-org---return-atmosphere-co2-to-300-ppm .

[3]. "300 ppm CO2 ASAP":

CANADIANS FOR ACTION ON CLIMATE CHANGE. Cory Morningstar (Canadians for Action on Climate) and Joan Russow PhD (Global Compliance Research Project) (2010): "Before COP15, during COP15 and POST COP15, there has been a global 350.org campaign. At COP15, states such as Bolivia, and the ALBA group, and some scientists and activists were calling for parts per million (ppm) of carbon dioxide to return to 300 ppm. When people from the 350.org campaign were asked why they did not respond to the lower demands, their response was ‘350.org is our campaign’. However, more and more leading climate activists and leading world scientists are advocating the necessity of returning to 300 ppm." [1].

[1]. Joan Russow and Cory Morningstar, "Climate change: a global imperative to return to 300 ppm", Canadians For Action on Climate Change", 9 April 2010: http://canadianclimateaction.wordpress.com/writings-2009-2010/climate-change-a-global-imperative-to-return-to-300-ppm/ .

CLIMATE CODE RED. David Spratt on the website called “Climate Code Red” (the title of a key book by David Spratt and Phillip Sutton) (2009): “The central point is that Arctic sea-ice is undergoing dramatic loss in summer, having lost 70-80% of its volume in the last 50 years, most since 2000. Without summer sea-ice, Greenland cannot escape a trajectory of ice-sheet loss leading to an eventual sea-level rise of 7 metres. Regional temperatures in the Arctic autumn are already up about 5C, and by mid-century an Arctic ice-free in summer, combined with more global warming, will be pushing Siberia close to the point where large-scale loss of carbon from melting permafrost would make further mitigation efforts futile. As Hansen told the US Congress in testimony last year, the “elements of a perfect storm, a global cataclysm, are assembled”. In short, if you don’t have a target that aims to cool the planet sufficiently to get the sea-ice back, the climate system may spiral out of control, past many “tipping points” to the final “point of no return”.

And that target is not 350ppm, it’s around 300 ppm. Hansen says Arctic sea-ice passed its tipping point decades ago, and in his presentations has also specifically identified 300-325ppm as the target range for sea-ice". [1].

[1]. David Spratt, “350 is the wrong target: put the science first”, Climate Code Red website, 22 January 2009: http://www.climatecodered.org/2009_01_01_archive.html .

CSIRO. Australia's premier research organization, the Commonwealth Scientific and Industrial Research Organization (CSIRO), “The Science of Climate Change” (see: http://www.csiro.au/files/files/poqu.pdf ), 2008 : “Since the Industrial Revolution, the CO2 concentrations have risen 37%, methane 150% and nitrous oxide 18%. The global increases in CO2 concentration are due primarily to fossil fuel use and land-use change, while the increases in methane and nitrous oxide are primarily due to agriculture. The CO2 concentration in 2008 of 383 parts per million (ppm) is much higher than the natural range of 172 to 300 ppm that existed over the last 800,000 years.” [1].

[1]. CSIRO, “The Science of Climate Change”, 2008: http://www.csiro.au/files/files/poqu.pdf .

GLOBAL COMPLIANCE RESEARCH PROJECT. Joan Russow PhD (Global Compliance Research Project) and Cory Morningstar (Canadians for Action on Climate) (2010): "Before COP15, during COP15 and POST COP15, there has been a global 350.org campaign. At COP15, states such as Bolivia, and the ALBA group, and some scientists and activists were calling for parts per million (ppm) of carbon dioxide to return to 300 ppm. When people from the 350.org campaign were asked why they did not respond to the lower demands, their response was ‘350.org is our campaign’. However, more and more leading climate activists and leading world scientists are advocating the necessity of returning to 300 ppm." [1].

[1]. Joan Russow and Cory Morningstar, "Climate change: a global imperative to return to 300 ppm", Canadians For Action on Climate Change", 9 April 2010: http://canadianclimateaction.wordpress.com/writings-2009-2010/climate-change-a-global-imperative-to-return-to-300-ppm/ .

NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION (NOAA). US Department of Commerce, National Oceanic and Atmospheric Administration (NOAA) (10 May 2013): “On May 9, the daily mean concentration of carbon dioxide in the atmosphere of Mauna Loa, Hawaii, surpassed 400 parts per million (ppm) for the first time since measurements began in 1958. Independent measurements made by both NOAA and the Scripps Institution of Oceanography have been approaching this level during the past week… Before the Industrial Revolution in the 19th century, global average CO2 was about 280 ppm. During the last 800,000 years, CO2 fluctuated between about 180 ppm during ice ages and 280 ppm during interglacial warm periods. Today’s rate of increase is more than 100 times faster than the increase that occurred when the last ice age ended… The increase in the Northern Hemisphere is always a little ahead of the Southern Hemisphere because most of the emissions driving the CO2 increase take place in the north. Once emitted, CO2 added to the atmosphere and oceans remains for thousands of years. Thus, climate changes forced by CO2 depend primarily on cumulative emissions, making it progressively more and more difficult to avoid further substantial climate change.” [1].

[1]. NOAA, “CO₂ at NOAA’s Mauna Loa Observatory reaches new milestone: Tops 400 ppm”, 10 May 2103: http://www.esrl.noaa.gov/gmd/news/7074.html .

ROYAL SOCIETY CORAL WORKING PARTY. Statement by the technical working group on coral, The Royal Society on 6th July 2009: "The Earth’s atmospheric CO₂ level must be returned to less than 350ppm to reverse this escalating ecological crisis and to 320ppm to ensure permanent planetary health. Actions to achieve this must be taken urgently. The commonly mooted best case target of 450ppm and a time frame reaching to 2050 will plunge the Earth into an environmental state that has not occurred in millions of years and from which there will be no recovery for coral reefs and for many other natural systems on which humanity depends. Working group signatories Professor John Veron (Coral Reef Research), Dr Mary Stafford-Smith (Coral Reef Research), Prof. Ove Hoegh-Guldberg (University of Queensland) [and 20 other eminent scientists]". [1].

[1]. Output of the technical working group meeting, The Royal Society, London, 6th July, 2009, “The Coral Reef Crisis: scientific justification for critical CO₂ threshold levels of less than 350ppm”: http://www.carbonequity.info/PDFs/The-Coral-Reef-Crisis.pdf .

TARGET 300. “Target 300” (that advocates a return to 300 ppm CO2 ASAP): “James Hansen, is the director of the NASA Goddard Institute for Space Studies and Adjunct Professor at the Columbia University Earth Institute. He is one of the worlds leading climate scientists. Hansen has recently released a paper titled "Target Atmospheric CO2: Where Should Humanity Aim?" In this paper he concludes that we need to return atmospheric concentrations to between 300-325 ppm CO2 to re-establish summer sea ice in the North Pole. The North Pole summer sea ice is just one of a number of critical climate systems that are needed to maintain a stable safe climate. Without it, other systems, including the Greenland ice mass and the frozen methane trapped in Arctic permafrost, will respond to global warming and add greatly to the problem by creating destructive sea level rise and massive release of additional greenhouse gases into the atmosphere. We don't know exactly where safe CO2 levels lie within the 300-325 ppm CO2 range so if we wish to avoid a climate catastrophe, we must aim for 300 ppm CO2 or below. Hansen has said we have at most decades to return our atmospheric greenhouse gas levels to safe levels.” [1].

[1]. Target 300: http://target300.org/1introduction.html .

YARRA VALLEY CLIMATE ACTION GROUP. Yarra Valley Climate Action Group (YVCAG) (Melbourne, Victoria, Australia) advocates “Urgent reduction of atmospheric CO₂ to a safe level of about 300 ppm CO2 as recommended by leading climate and biological scientists.” [1].

[1]. Yarra Valley Climate Action Group: http://sites.google.com/site/yarravalleyclimateactiongroup/Home .

War is the penultimate in racism and genocide the ultimate in racism. It is very powerful to quote expert opinion. Thus eminent physicist Stephen Hawking on the key existential threats facing Humanity (2018): “We see great peril if governments and societies do not take action now to render nuclear weapons obsolete and to prevent further climate change” (Stephen Hawking, “Brief Answers to the Big Questions”, John Murray, 2018, Chapter 7). Most of the following websites alphabetically list expert opinions in 4 inter-connected key areas, namely “Reverse climate change”, “Stop lying and censorship”, “End war and genocide”, and “Free Palestine”, Everyone is invited to make use of this substantial resource and to feel free to disseminate this list to everyone they can.

REVERSE CLIMATE CHANGE

“1% on 1%: one percent annual wealth tax on One Percenters”: https://sites.google.com/site/300orgsite/1-on-1 .

“2 degrees C”: https://sites.google.com/site/300orgsite/2-degrees-c .

“100% renewable energy by 2020”: https://sites.google.com/site/100renewableenergyby2020/ .

“300 ppm CO2 ASAP: https://sites.google.com/site/300orgsite/300-ppm-co2-asap .

“2011 climate change course”: https://sites.google.com/site/300orgsite/2011-climate-change-course .

“300.org”: . https://sites.google.com/site/300orgsite/300-org .

“300.org climate crisis glossary”: https://sites.google.com/site/climategenocide/300-org-climate-crisis

“300.org – return atmosphere CO2 to 300 ppm CO2”: https://sites.google.com/site/300orgsite/300-org---return-atmosphere-co2-to-300-ppm .

“Are we doomed?”: https://sites.google.com/site/300orgsite/are-we-doomed .

“Banyule Climate Action Now”: https://sites.google.com/site/banyuleclimateactionnow/ .

“Biofuel Genocide”: https://sites.google.com/site/biofuelgenocide/ .

“Carbon Debt Carbon Credit”: https://sites.google.com/site/carbondebtcarboncredit/ .

“Climate crisis articles”: https://sites.google.com/site/climatecrisisarticles/home .

“Climate Genocide”: https://sites.google.com/site/climategenocide/ .

“Climate Justice & Intergenerational Equity”: https://sites.google.com/site/300orgsite/climate-justice .

"Climate Revolution Now": https://sites.google.com/site/300orgsite/climate-revolution .

“Cut carbon emissions 80% by 2020”: https://sites.google.com/site/cutcarbonemissions80by2020/ .

“Divest from fossil fuels”: https://sites.google.com/site/300orgsite/divest-from-fossil-fuels .

“Eco-socialism, green socialism”: https://sites.google.com/site/ecosocialismgreensocialism/

“Gas is not clean energy”: https://sites.google.com/site/gasisnotcleanenergy/ .

“Methane bomb threat”: https://sites.google.com/site/methanebombthreat/ .

“Nuclear weapons ban, end poverty & reverse climate change”: https://sites.google.com/site/300orgsite/nuclear-weapons-ban .

“Older people and climate change”: https://sites.google.com/site/olderpeopleandclimatechange/home .

“Science and economics experts: carbon tax needed and not carbon trading”, 300.org: https://sites.google.com/site/300orgsite/sciennce-economics-experts-carbon-tax-needed-not-carbon-trading .

“Stop air pollution deaths”: https://sites.google.com/site/300orgsite/stop-air-pollution-deaths .

“Stop climate crime”: https://sites.google.com/site/300orgsite/stop-climate-crime .

"Too late to avoid global warming catastrophe": https://sites.google.com/site/300orgsite/too-late-to-avoid-global-warming .

“Yarra Valley Climate Action Group”: https://sites.google.com/site/yarravalleyclimateactiongroup/Home .

STOP LYING & CENSORSHIP

“ABC censorship”: https://sites.google.com/site/abccensorship/abc-censorship .

“ABC fact-checking unit & incorrect reportage by the ABC (Australia’s BBC)”: https://sites.google.com/site/mainstreammediacensorship/abc-fact-checking-unit .

“Boycott Murdoch media”: https://sites.google.com/site/boycottmurdochmedia/ .

“Censorship by ABC Late Night Live”: https://sites.google.com/site/censorshipbyabclatenightlive/ .

"Censorship by ABC Saturday Extra": https://sites.google.com/site/censorshipbyabclatenightlive/censorship-by-abc-sat .

“Censorship by the ABC”: https://sites.google.com/site/censorshipbytheabc/ .

“Censorship by Crikey (Australia)”: https://sites.google.com/site/mainstreammediacensorship/censorship-by-crikey .

“Censorship by SBS (Australia)”: https://sites.google.com/site/mainstreammediacensorship/censorship-by-sbs-australia .

“Censorship by The Age”: https://sites.google.com/site/mainstreammediacensorship/censorship-by-the-age .

“Censorship by the BBC”: https://sites.google.com/site/censorshipbythebbc/ .

“Censorship by The Conversation”: https://sites.google.com/site/mainstreammediacensorship/censorship-by .

"Censorship by The Guardian Australia": https://sites.google.com/site/mainstreammediacensorship/home/censorship-by-the-guardian-a .

"Censorship by The Guardian UK": https://sites.google.com/site/mainstreammediacensorship/censorship-by-the-guardian-uk .

“Educational apartheid”: https://sites.google.com/site/educationalapartheid/ .

“Experts: US did 9/11”: https://sites.google.com/site/expertsusdid911/ .

“Expose holocaust denial & ignoring”: https://sites.google.com/site/exposeholocaustdenialignoring/Home .

“Exposing Australia”: https://sites.google.com/site/exposingaustralia/home .

“Free university education” : https://sites.google.com/site/freeuniversityeducation/home

“Lying by omission”: https://sites.google.com/site/mainstreammedialying/lying-by-omission .

“Mainstream media censorship”: https://sites.google.com/site/mainstreammediacensorship/home .

“Mainstream media lying”: https://sites.google.com/site/mainstreammedialying/ .

“Questions Q&A won’t ask”: https://sites.google.com/site/questionsqawontask/home .

“Subversion of Australia”: https://sites.google.com/site/subversionofaustralia/home .

END WAR AND GENOCIDE

“Aboriginal Genocide”: https://sites.google.com/site/aboriginalgenocide/ .

“Afghan Holocaust, Afghan Genocide”: https://sites.google.com/site/afghanholocaustafghangenocide/ .

“Iraqi Holocaust, Iraqi Genocide”: https://sites.google.com/site/iraqiholocaustiraqigenocide/ .

“Afghanistan Genocide essays”: https://sites.google.com/site/afghanistangenocideessays/ .

“Art for peace, planet, mother & child”: https://sites.google.com/site/artforpeaceplanetmotherchild/ .

“Bengali Holocaust (WW2 Bengal Famine) writings of Gideon Polya”: https://sites.google.com/site/drgideonpolya/bengali-holocaust .

“Gideon Polya”: https://sites.google.com/site/drgideonpolya/home .

“Gideon Polya writing”: https://sites.google.com/site/gideonpolyawriting/ .

“Iraq Genocide essays”: https://sites.google.com/site/iraqgenocideessays/ .

“Muslim Holocaust Muslim Genocide”: http://sites.google.com/site/muslimholocaustmuslimgenocide/ .

“Poetry reviews by Gideon Polya”: https://sites.google.com/site/poetryreviewsbygideonpolya/ .

“Report genocide”: https://sites.google.com/site/reportgenocide/ .

"State crime and non-state terrorism": https://sites.google.com/site/statecrimeandnonstateterrorism/ .

“Stop state terrorism”: https://sites.google.com/site/stopstateterrorism/ .

FREE PALESTINE

Apartheid Israeli state terrorism: (A) individuals exposing Apartheid Israeli state terrorism, and (B) countries subject to Apartheid Israeli state terrorism”: https://sites.google.com/site/palestiniangenocide/apartheid-israeli-state-terrorism .

“Boycott Apartheid Israel”: https://sites.google.com/site/boycottapartheidisrael/.

“Gaza Concentration Camp”: https://sites.google.com/site/palestiniangenocide/gaza-concentration .

“Jews Against Racist Zionism”: https://sites.google.com/site/jewsagainstracistzionism/ .

“Non-Jews Against Racist Zionism”: https://sites.google.com/site/nonjewsagainstracistzionism/ .

“One-state solution, unitary state, bi-national state for a democratic, equal rights, post-apartheid Palestine: https://sites.google.com/site/boycottapartheidisrael/one-state-solution .

“Palestinian Genocide”: https://sites.google.com/site/palestiniangenocide/ .

“Palestinian Genocide essays”: https://sites.google.com/site/palestinegenocideessays/ .

"Zionist quotes re racism and Palestinian Genocide": https://sites.google.com/site/palestiniangenocide/zionist-quotes .