A “hiatus” in global warming so far this century is partly caused by natural climate variations and is unlikely to last, a draft UN report by leading climate scientists reveals.
The draft of the Intergovernmental Panel on Climate Change (IPCC) report, and a summary which is due for release in Stockholm next week, says that factors including a haze of volcanic ash and a cyclical dip in energy emitted from the Sun may also have contributed to slower warming trends. The fact that temperatures have risen more slowly in the past 15 years despite rising emissions of greenhouse gases has emboldened some global-warming sceptics who challenge the evidence for man-made climate change and question the need for urgent action.
But the IPCC draft does not project any long-term respite.
Instead, it forecast a resumption in the warming trend that is likely to cause ever more heatwaves, droughts, floods and rising sea levels. “Barring a major volcanic eruption, most 15-year global mean surface temperature trends in the near-term future will be larger than during 1998-2012,” says a draft of the report obtained by Reuters.
Temperatures are likely be 0.3 to 0.7C higher from 2016-35 than from 1986-2005, it says. The report by the IPCC, updating an overview of climate change completed in 2001, is the main guide for government action.