O’ROURKE, on global warming: “This is our final chance. The scientists are absolutely unanimous on this. That we have no more than 12 years to take incredibly bold action on this crisis.” — remarks in Keokuk, Iowa, on Thursday.
THE FACTS: There is no scientific consensus, much less unanimity, that the planet only has 12 years to fix the problem.
A report by the United Nations Intergovernmental Panel on Climate Change, drawn from the work of hundreds of scientists, uses 2030 as a prominent benchmark because signatories to the Paris agreement have pledged emission cuts by then. But it’s not a last chance, hard deadline for action, as it has been interpreted in some quarters.
“Glad to clear this up,” James Skea, co-chairman of the report and professor of sustainable energy at Imperial College London, told The Associated Press. The panel “did not say we have 12 years left to save the world.”
He added: “The hotter it gets, the worse it gets, but there is no cliff edge.”
“This has been a persistent source of confusion,” agreed Kristie L. Ebi, director of the Center for Health and the Global Environment at the University of Washington in Seattle. “The report never said we only have 12 years left.”
The report forecasts that global warming is likely to increase by 0.5 degrees Celsius or 0.9 degrees Fahrenheit between 2030 and 2052 “if it continues to increase at the current rate.” The climate has already warmed by 1 degree C or 1.8 degrees F since the pre-Industrial Age.
Even holding warming to that level brings harmful effects to the environment, the report said, but the impact increases greatly if the increase in the global average temperature approaches 2 degrees C or 3.6 degrees F.
“The earth does not reach a cliff at 2030 or 2052,” Ebi told AP. But “keep adding greenhouse gases to the atmosphere and temperatures will continue to rise.”
As much as climate scientists see the necessity for broad and immediate action to address global warming, they do not agree on an imminent point of no return.
Cornell University climate scientist Natalie M. Mahowald told the AP that a 12-year time frame is a “robust number for trying to cut emissions” and to keep the increase in warming under current levels.
But she said sketching out unduly dire consequences is not “helpful to solving the problem.”