What of 2C? – Aaron Kressig
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The Forum for Climate Engineering Assessment asked one of its researchers to answer the question: “Who is saying what about the likelihood of staying below a 2 degrees Celsius rise above pre-industrial atmospheric temperatures?” The results beg the question, should researchers and policy-makers be thinking more seriously and openly about climate engineering research?
Since the Copenhagen Accord in 2009, the goal of the international climate talks has been to hold global warming to a 2 degree Celsius rise above pre-industrial levels.
The start of the 21st Conference of the Parties to the UN Framework Convention on Climate Change in Paris is days away, and intended nationally determined contributions (INDCs) have been submitted by 150 countries. Climate scientists have begun to calculate how we are doing on the 2C goal, and the math is a little frightening. Not only do we have little wiggle room in terms of how much carbon we can emit to have any certainty of staying under this limit, but it will be global actions in the next two decades that determine our fate.
The calculations of planetary warming and average temperatures can be a difficult concept for anyone to get their mind around. One way to understand this topic is through the lens of a global carbon budget. This is the amount of carbon emissions that the planet can release and still stay under our stated goal. The most recent Intergovernmental Panel on Climate Change (IPCC) report estimated from 2011 onwards we would need to emit less than 800 billion tonnes (Gt) of C02e (carbon dioxide equivalent, a measure that takes account of the warming potential of other greenhouse gases) to have a 66% chance of staying under 2C. From 2011 to the end of 2015 the combined effect of greenhouse gas emissions has reduced our remaining quota to 603 Gt of CO2e. While the exact calculations that go into carbon budget estimations are hotly contested, they all agree on one thing: the budget is disappearing quickly.
In order to understand the magnitude of the 2C challenge, it’s helpful to analyze some models which show how the world could, theoretically, stay under 2C.
The Cambridge Architectural Research model shows a pathway that gets us close to our goal. The model has the world peaking emissions in 2016, decreasing by 17% by 2030, by 50% in 2050, and slowly reaching zero carbon emissions by 2100. This model, which proposes radical efforts towards emission reductions (especially by the developing world), would leave us less than a 50% chance of staying under the 2C threshold.
What about the INDCs that the world’s nations have laid out as a pathway towards emission reductions? These efforts represent a historic event in global climate governance, and offer the world for perhaps the first time a real strategy towards reducing our effect on climate change. However, even if all of these INDCs were met, we would still be short of our goal. The Climate Action Tracker, “an independent scientific analysis produced by four research organisations tracking climate action,”shows that if current INDCs are met, we would be on track for a range of warming between 2.2-3.4 degrees Celsius. It also shows that if current policies are held in place and INDCs are not moved forward, warming by 2100 is projected to be between 2.9-4.6 degrees Celsius.
Research outlined in a paper released in October in Environmental Research Letters makes the challenge of achieving the 2C goal through the current INDCs even more tangible. The research shows that even if INDC goals were achieved, the EU, China, and the US alone will use the remaining global carbon budget allowed to the world, if we are to have a 66% chance of staying under 2C by 2040. This means that 2 billion people are likely to push us over the limit in the next 25 years, and does not even begin to account for countries like India, Brazil, South Africa and others whose fossil fuel use are still increasing. This paper provides real doubt on whether it is realistic to think that 2C is a possibility unless drastic political action is taken.
What’s more troubling is that there are many signs emerging that even accomplishing our current INDCs may be hard enough to achieve, given rising demands for power. For instance, though it has ambitious plans to improve energy efficiency and increase solar and wind power production, India’s Central Electric Authority recently released its plans to double its electrical capacity powered by coal-fired power plants in the next five years. China, which uses more coal than any other country, in October was found to have been under-reporting its coal consumption by up to 17%, according to research done by the New York Times. Even with drastic action beyond INDCs by the developed world, emissions from increased power needs of the developing world may be enough to take us over the limit.
The developed world is also faced with uncertainty regarding its INDCs. Despite recent surges in the renewable fuel industry, investment in renewable energies may plateau in the coming years. The International Energy Agency’s Renewable Energy Report predicts that electrical generation from renewable energy will grow from 22%-26% from 2013-2020, but then is expected to level off. Policy uncertainties regarding subsidies, conflict with established fossil fuel industries, and continued need for innovations and improvements to renewable capacity may lead to the leveling off of their growth in the developed world. With Japan, Europe, and the United States lukewarm about nuclear power, it would seem the world’s major economies will continue to rely on fossil fuels for a major portion of its electrical generation. This creates great uncertainty around the ability of the world to meet their INDCs, which as stated, are not enough to keep us at 2C.
Scientific reports emerging in the last year as the world prepares for the international climate talks reveal several important points. For the first time there is scientific evidence to show where our current actions are taking us, and while there is progress, our trajectory is frightening. Global efforts are insufficient and novel strategies must be undertaken if we are to have any chance of staying below the 2C threshold. The idea of the carbon budget has allowed the world to see the direct relationship between emissions and temperature rise, and has demonstrated that current emission rates do not correlate with the goal we have laid out. If we are serious about our goal, this means a change of strategy is in order.
The critical years for limiting warming in the 21st century are upon us right now. The infrastructural transitions towards energy efficiency and renewable energy must be made now; if we wait even five years, it may be too late to chart a pathway to stay under 2C. Transitions take time, and we are running out of it.
I’ve included below a break down of the findings of my research for this post.
2 Degrees Centigrade Research - Part One: Understanding the Challenge of holding the line at 2C
|IPCC 5th Assessment Report Summary||-Carbon Budget Calculations|
-In order to have a 66% chance of staying under 2.0o C we need to release less than 2,900 billion metric tonnes (Gt) of CO2
-Between 1870-2011 1,900 Gt of CO2 were emitted; only leaving 1,000 Gt CO2 (34%) remaining in 2011.
|Carbon Briefing||-When the warming potential of other greenhouse gases are accounted for, the remaining budget calculated by 2011 levels drops to 800 Gt CO2e |
-The CO2e unit accounts for the warming potential of all GHGs, with carbon as the standard unit.
|Carbon Now||-Between 2011 and the end of 2015 average annual CO2 emissions were 36.5 Gt CO2;|
-Since the IPCC’s last calculation, 146 Gt of CO2 will have been emitted.
|NOAA's Annual Greenhouse Gas Index||-Between 2011-2015, the radiative forcing of non-GHGs accounted for 35.82% of total warming, equivalent to 51 Gt of CO2.|
-When the current carbon budget is calculated in terms of Gt of CO2e (all GHGs accounted for), about 603 Gt of CO2e, or 20.7% of the original budget, remain to be emitted.
|LINK (scroll to AGGI Index)|
|Yale: Environment 360||Uncertainty remains on exact calculations of carbon budgets, but it is clear throughout reports that we are rapidly using it up.||LINK|
|Cambridge Architectural Research.||-If global emissions peak in 2015, decrease by 17% by 2030, and by 50% in 2050 we will still emit 3,193 Gt of CO2e by 2100 and have less than a 50% chance of staying under 2C threshold.||LINK|
(Cambridge Architectural Research in scenarios option)
|IPCC AR5 RCP 2.6||-If global emissions peak in 2015, decrease by 66% by 2050 and we reach zero carbon emission by 2100, a total of 2,766 Gt of CO2e will be released by 2100 and we will have a better than 66% chance of staying under 2oC.||LINK|
(select RCP 2.6 in scenarios option)
|“Measuring a Fair and Ambitious Climate Agreement Using Cumulative Emissions”||-If current INDCs are held US, China, and EU will use up the world’s climate budget required for a 66% chance of staying under 2oC by 2040.|
-If the carbon budget was to be split up by the so called equity model, all global countries were to be given an equal share of the remaining carbon budget based on current and past emissions…
-United States would need to cut emissions by over 95% by 2030
-EU would need to cut emissions by 63% by 2030
-China would need to peak in 2020 and then sharply cut emissions by 66% by 2030.
-India would need to peak by 2025, and then reduce by over 40% of that level from 2050.
|Climate Action Tracker||-Current policies will cause a warming between 2.7-4.9 degrees Celsius rise, with the median rise at 3.6C|
-Current INDCs that account for 86% of global emissions, if met by all parties, would cause a warming between 2.2-3.4 degrees Celsius rise, with a median increase of 2.7C
-Current policies model represents what policy as of today is leading us towards (without increasing ambition of governments) and INDCs model represents if ALL INDCs are met.
2 Degrees Centigrade Research- Part Two: Why the Challenge May Be Too Great to Overcome
|Global Carbon Project||-Global carbon emissions are not only increasing, but increasing more rapidly in 2014|
-Slight decrease in carbon footprint of developed world is overcome by the rapid growth of the developing
|IEA Renewable Energy Report||-Renewable energy is expected to grow from 22% of world’s electrical generation in 2013 to 26% in 2020, but then it is expected to level off|
-This would increase the likelihood that INDCs are not met
-This is largely due to policy uncertainties in the US, Australia, and other developed countries
|US EIA||-India is set to increase its coal consumption for electricity from 650 million metric tons in 2015 to 1500 metric tons in 2020.|
-This would greatly increase its carbon footprint and cause it to surpass the U.S. in coal consumption
-This fact alone undercuts any possibility of the scenarios listed in Part One from having a real chance of happening.
|US EIA||-Global coal use is projected to increase by up to 25% between 2015 and 2030.||LINK|
|The Guardian||-Data suggests that China has been under reporting its coal use by up to 17%||LINK|
∙Various scenarios provided in Part One to achieve 2oC require drastic action, especially by the biggest emitters.
∙INDCs alone will not be enough to achieve 2oC with any certainty, and policy uncertainties regarding alternatives in developed world and plans for increased fossil fuel use in the developing world lead to questions about whether INDCs are even a realistic possibility.
∙China, the US, and the EU alone have the potential to push us over the carbon budget by 2040.
Aaron Kressig is a research assistant with the Forum for Climate Engineering Assessment and an intern in the Climate and Energy Program at World Resources Institute. He graduated with a B.A. in Geography from the University of Missouri in May 2015 and is currently a first year masters candidate in the Global Environmental Politics Program in the School of International Service at American University.
- Duality in Climate Science by Kevin Anderson.
Available at http://kevinanderson.info/blog/duality-in-climate-science/
- Global Calculator. http://tool.globalcalculator.org/
- Measuring a Fair and Ambitious Climate Agreement Using Cumulative Emissions by Glen P. Peters. Available at http://iopscience.iop.org/article/10.1088/1748-9326/10/10/105004
- Climate Action Tracker. http://climateactiontracker.org/
- Medium-Term Renewable Energy Market Report, International Energy Agency. https://www.iea.org/bookshop/708-Medium-Term_Renewable_Energy_Market_Report_2015
- “China underreporting coal consumption by up to 17%, data suggests”. Tom Phillips, The Guardian. http://www.theguardian.com/world/2015/nov/04/china-underreporting-coal-consumption-by-up-to-17-data-suggests
- “What is the carbon budget? That depends on who you ask.” Yale Environment 360, 2014 http://e360.yale.edu/feature/what_is_the_carbon_limit_that_depends_who_you_ask/2825/
- NOAA Annual Greenhouse Gas Index (AGGI) http://www.esrl.noaa.gov/gmd/aggi/
- Carbon Now http://co2now.org/Current-CO2/CO2-Now/global-carbon-emissions.html