Two reports issued last fall shook up the assumption that holding global warming to no more than 2oC above pre-industrial levels would be sufficient to avert catastrophic climate change. The Intergovernmental Panel on Climate Change (IPCC) reported that the much safer goal is 1.5oC.
Both goals were mentioned in the Paris climate accord, but the new IPCC report shows that 20C of warming would result in significantly more adverse impacts. The IPCC also shook up the global timetable for mitigating climate change, saying the world is on track to exhaust its “carbon budget” in 12 years or so.
This means the global carbon emissions must peak well before 2030, but that’s not the path we’re on. Global emissions are climbing. So are U.S. emissions, which have been declining in recent years but increased in 2018. U.S. will rise even higher as a result of President Trump’s policies, including his reversal of President Obama’s Climate Action Plan and aggressive increases in vehicle efficiency.
A month later, the U.S. Global Change Research Program, consisting of climate scientists from 13 federal agencies, issued its Fourth National Climate Assessment with new insights into the adverse impacts the U.S. can expect from global warming.
President Trump waved off both studies and stuck to his positions that a) climate change is not real, and b) climate scientists have hidden agendas.