Dr Gideon Polya is a biochemist, academic, writer, artist, and climate change activist. Associated with the Australian Climate Emergency Network and the Yarra Valley Climate Action Group, he is the Convenor of 300.org that, informed by the latest science, holds that we must return the world's atmospheric CO2 concentration to 300 ppm for a safe and sustainable planet for all peoples and all species (see: .http://mwcnews.net/Gideon-Polya ).
In December 2012 Dr Gideon Polya estimated that the world has 5.3 years at current and projected rates of greenhouse gas (GHG) pollution before it exceeds the terminal carbon budget of 600 Gt CO2 that must not be exceeded if the world is to have a 75% chance of avoiding a catastrophic 2C temperature rise [1]. Accordingly, as of December 2013 we have only about 4 years left to zero GHG emissions.
Dr Gideon Polya on the world having only 5 years left before it exceeds the world’s 600 Gt CO2 terminal greenhouse gas (GHG) pollution budget (2012): “Our warming world is badly running out of time to deal with man-made climate change and keep temperature rise to within 2 degrees Centigrade (2oC) - but how much time have we left? Answer: 5.3 years. The basis for this appalling conclusion is set out below… In a 2009 report entitled "Solving the climate dilemma: a budget approach" the WBGU, that advises the German Government on climate change, estimated that for a 75% chance of avoiding a 2C (2oC, 2 degree Centigrade, 2 degree Celsius) temperature rise (EU policy and majority global policy since the 2009 Copenhagen Climate Change Conference) the world can emit no more than 600 billion tonnes CO2 (carbon dioxide) (600 Gt CO2) between 2010 and zero emissions in 2050 (see WBGU, “Solving the climate dilemma: the budget approach”). Since CO2 is the most important greenhouse gas (GHG) we could roughly set the world’s terminal GHG pollution budget at 600 Gt CO2-e (CO2-equivalent, this term including other GHGs). Relative to commencement in 2010, how many years have we left before we exceed this terminal CO2 pollution budget of 600 Gt CO2-e?
The US Energy Information Administration (US EIA) provides detailed statistics on CO2 pollution and has provided estimates of global energy-related CO2 pollution between 2005 (28.181 Gt CO2) and 2035 (43.220 Gt CO2) (see US EIA, “Energy-related carbon dioxide emissions”, Table A10). Using this expertly-determined, year-by-year estimate of global energy-related CO2 emissions one can estimate that the post-2009 total will reach 588 Gt by the end of 2026 and 628 Gt by the end of 2028 i.e. the terminalCO2 pollution budget will be exceeded in mid-2027 or in roughly 14.5 years from now…
The Global Warming Potential (GWP) of CH4 relative to that if CO2 (1.0) is 21 on a 100 year time frame but on a 20 year time frame and taking aerosol impacts into account, it is 105. This re-assessment of the GWP of CH4 becomes of great importance in assessing how many years we have left to tackle GHG pollution (see 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 ).
.In 2009 World Bank analysts used an estimate of a GWP of 72 for CH4 on a 20 year time frame to re-assess the contribution of livestock to man-made GHG pollution as over 32.564 Gt CO2-e/year of which 5.047 GT CO2-e/year is due to undercounted methane. This re-assessment lifts the annual GHG pollution from 41.744 Gt CO2-e to 63.803 Gt CO2-e. Assuming that live-stock-related GHG pollution increases in direct proportion ion to energy-related CO2 emissions, one can estimate that the world will reach 551.738 Gt CO2-e in 2017 and 624.363 Gt CO2-e in 2018 i.e. the World has 5.8 years at present rates before it exceeds the terminal CO2-e budget.
However one can re-assess the World Bank re-assessment by consider that CH4 has a GWP relative to CO2 of 105. This re-assessment indicates that the World will reach 573.167 Gt CO2-e in 2017 and 648.547 Gt CO2-e in 2018 i.e. the World has 5.3 years at present rates before it exceeds the terminal CO2-e budget. of 600 Gt CO2-e.” [1].
[1] Gideon Polya, “Doha climate change inaction. Only 5 years left to act”, MWC News, 9 December 2012: http://mwcnews.net/focus/analysis/23373-gideonpolya-climate-change.html .