Political action the biggest swing factor in meeting climate targets, research says

January 2, 2013

The most important factor affecting the likelihood of limiting climate change to internationally agreed targets is when people start to do something about it, according new research from IIASA, ETH Zurich, and other institutions.

The new study, published today in the journal Nature, examined the probability of keeping average from rising more than 2°C above preindustrial levels under varying levels of stringency, and thus mitigation costs. In addition, the study for the first time quantified and ranked the uncertainties associated with efforts to mitigate change, including questions about the climate itself, uncertainties related to future technologies and , and political uncertainties as to when action will be taken.

The climate system itself is full of uncertainty – an oft-used argument to postpone climate action until we have learned more. "We wanted to frame the problem in a new way and try to understand which uncertainties matter in trying to limit global warming by specific climate action," says Joeri Rogelj, ETH researcher and lead author on the paper, who carried out the research at IIASA.

The most important uncertainty, according to the study, is political – that is, the question of when countries will begin to take serious action to reduce greenhouse gas emissions and implement other policies that could help mitigate climate change. Keywan Riahi, IIASA program leader and study co-author says, "With a twenty-year delay, you can throw as much money as you have at the problem, and the best outcome you can get is a fifty-fifty chance of keeping temperature rise below two degrees." Two degrees is the level that is currently supported by over 190 countries as a limit to avoid dangerous climate change.

Social uncertainties, which influence consumer energy demand, were second-most important, the study found. Social uncertainties refer to things like people's awareness and choices with respect to energy and to the adoption of efficient technologies.

"How much energy the world consumes going forward turns out to be a much bigger swing factor for climate change than the availability of technologies like solar and wind power, biofuels, and so on," said IIASA researcher David McCollum, another co-author. "Energy efficiency, improved urban planning, lifestyle changes – these things on the demand side of the energy equation are so important; yet they receive relatively little attention compared to the supply side."

The researchers examined geophysical and technological uncertainties and found that while the climate system and energy supply technologies are generally seen as the major factors for climate, they ranked below political and social uncertainties in the new study. Geophysical uncertainties refer to the unknown – and unknowable – factors about how the will react to . Technological uncertainties refer to questions about which energy supply and carbon capture systems will be available in the future.

The authors used scenarios to define how these factors affect the probability of staying within a given temperature target, at a variety of carbon prices. In addition to the 2°C target, the researchers also explored the distribution of costs and risks for limiting to below 1.5°C and 3°C. Even for a 3°C target, a 20-year delay in the most stringent greenhouse gas reductions in combination with a high demand future means that there would remain a one in three chance that temperatures exceed 3°C. At the same time, limiting warming to 1.5°C with at least a fifty-fifty chance (a target supported by the least-developed countries and small island states) appears only to be possible if the world starts acting on now and turns towards an energy-efficient future.

Surprisingly, while much research is focused on understanding the global climate, a highly complex system with many uncertainties, the new study finds that after a certain point, there is little chance of limiting temperature rise to below 2°C. "Ultimately, the geophysical laws of the Earth system and its uncertainties dictate what global temperature rise to expect," said Rogelj. "If we delay for twenty years, the likelihood of limiting to two degrees becomes so small that the geophysical uncertainties don't play a role anymore."

Explore further: Action by 2020 key for limiting climate change, researchers say

More information: Rogelj, J., D. McCollum, A. Reisinger, M. Meinshausen & K. Riahi (2013) Probabilistic cost distributions for climate change mitigation. Nature, DOI:10.1038/nature11787

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5 / 5 (3) Jan 02, 2013
Try getting elected on a pro-science, pro-education, pro-planet platform. Try finding a politician that even wants to.
3 / 5 (2) Jan 02, 2013
Try getting elected on a pro-science, pro-education, pro-planet platform. Try finding a politician that even wants to.

President Obama got elected.
5 / 5 (1) Jan 02, 2013
The NPD in Canada almost did it. Had the voters realized earlier the shift was possible and moved away from defensive voting it would have. Three days more before the vote, maybe a week, and knowledge of the possibility would have spread far enough to have worked.

Edit: Then again, I guess that's Canada.

I really wish there was true proportional representation.
Jack Wolf
5 / 5 (2) Jan 03, 2013
Several years ago I noticed that most climate change reports and scientific papers use a less than realistic emission scenarios in their calculations. Since these emissions are long lived, this has led to a deepening concern about the climate situation and it's impacts today.

This important talk by Dr. Anderson at the 2012 Cabot Lecture (link below) clearly points the finger at scientists for not accurately reporting how bad the climate situation is. He also explains why we cannot meet the 2 degree C (3.8 F) target set by the world's government and its impacts on us today. His talk is timely in light of this week's paper from the World Bank that found:

"Even with the current mitigation pledges fully implemented, there is roughly a 20% likelihood of exceeding 4°C by 2100. If they are not met, warming of 4°C could occur as early as the 2060s."

Globally, we are nowhere close to meeting our mitigation pledges and long lived CO2 emissions continue to accumulate
1 / 5 (5) Jan 03, 2013
Read this paper Jack. It may not be as bad as you think? Perhaps it is all natural variation that we are freaking out about and nothing needs to be done?

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