It may be too late to stop climate change, but some of its most dangerous effects can be delayed, according to the first study that looks at climate, policies and impacts over time. The study, by a team of primarily U.K. scientists, concludes that while climate change impacts that are avoidable with policy changes are small by 2030 and 2050, an ounce of policy prevention today eventually becomes a pound of cure by 2100.
In other words, strong emissions policies today can delay for decades the climate change troubles that would occur in 2100 or earlier in the absence of any policies.
“It goes to how do you want to hedge your bets with mitigation policies,” said Nigel Arnell of the Walker Institute for Climate System Research at the University of Reading and lead author of the study. “Policy buys quite a lot of time. If you delay impacts, that buys time for adaptation.”
The team found that the most stringent greenhouse gas emissions policies would give us a 50/50 chance of remaining below a 2-degree Celsius global temperature rise by 2100, which reduces impacts on a wide range of sectors by 20 to 65 percent. That's compared to the “business as usual” path, which puts us at a dangerous 4-degree C temperature rise by 2100.
The impacts that can be avoided by 2100 are also strongly influenced by the date and level at which emissions peak than the rate of decline of emissions, the team concluded. The study, which details impacts over time under different policy regimes to a range of sectors (agricultural, energy, coastal flooding, water resources, etc), was published in Sunday's edition of the journal Nature Climate Change.
The study is being regarded as helpful because it finally and for the first time puts numbers on what climate scientists have long suspected, providing policymakers with something they can use in making decisions, said climate researcher Gavin Schmidt of NASA's Goddard Institute for Space Studies and blogger for RealClimate.org.
“What (scientists) have provided policymakers in the past is not really very useful,” said Schmidt.
Specifics on what can be done and how it could affect different sectors have been largely buried in scientific reports, he said. This study, however, is specific enough that it begins to give policymakers details they can use, he added.
That said, Arnell cautions that the study has a lot of limitations.