Infrastructure protectionTo keep global average temperature from rising above 2°C, action should be taken by 2020
Limiting climate change to target levels will become much more difficult to achieve, and more expensive, if action is not taken soon, according to a new analysis; a new study explores technological, policy, and social changes that would need to take place in the near term in order to keep global average temperature from rising above 2°C, a target supported by more than 190 countries as a global limit to avoid dangerous climate change
Limiting climate change to target levels will become much more difficult to achieve, and more expensive, if action is not taken soon, according to a new analysis from ETH Zurich, International Institute for Applied Systems Analysis (IIASA), and National Center for Atmospheric Research (NCAR).
The new paper, published yesterday in Nature Climate Change, explores technological, policy, and social changes that would need to take place in the near term in order to keep global average temperature from rising above 2°C, a target supported by more than 190 countries as a global limit to avoid dangerous climate change. An ETH Zurich release reports that this study for the first time comprehensively quantifies the costs and risks of greenhouse gas emissions surpassing critical thresholds by 2020. The findings of the study are particularly important given the failure of the recent climate negotiations in Doha to decide to increase mitigation action before 2020. The authors show that the 2°C target could still be reached even if greenhouse gas emissions are not reduced before 2020, but only at very high cost, with higher climate risks, and under exceedingly optimistic assumptions about future technologies. The more emissions are reduced in the near term, the more options will be available in the long run and, by extension, the cheaper it will be to reach international climate targets.
“We wanted to know what needs to be done by 2020 in order to be able to keep global warming below two degrees Celsius for the entire twenty-first century,” says Joeri Rogelj, lead author of the paper and researcher at ETH Zurich. The team of researchers analyzed a large array of potential scenarios for limiting global temperature rise to 2 °C above preindustrial levels, a target set by international climate agreements. Projections based on current national emissions pledges suggest that global carbon dioxide equivalent (CO2e) emissions will reach 55 gigatons (billion metric tons, Gt) or more per year in 2020, up from approximately 50 Gt today. At such levels, it would still be possible to reach the 2°C target in the long term, though it would be more difficult and expensive than if near-term emissions were lower.
Advanced technology strategies
For instance, nuclear power would need to remain on the table as a mitigation option, or people would need to quickly adopt advanced technology strategies, including electric vehicles and highly efficient energy end-use technologies such as appliances, buildings, and
