The warming is faster, more extreme than scientists anticipated
Climate Change Is Happening Faster Than Expected, and It’s More Extreme
New research suggests human-caused emissions will lead to bigger impacts on heat and extreme weather, and sooner than the IPCC warned just three years ago.
Inside Climate News.org, Dec. 27, 2017
In the past year, the scientific consensus shifted toward a grimmer and less uncertain picture of the risks posed by climate change.
When the UN's Intergovernmental Panel on Climate Change issued its 5th Climate Assessment in 2014, it formally declared that observed warming was "extremely likely" to be mostly caused by human activity.
This year, a major scientific update from the U.S. Global Change Research Program put it more bluntly: "There is no convincing alternative explanation."
Other scientific authorities have issued similar assessments:
The Royal Society published a compendium of how the science has advanced, warning that it seems likelier that we've been underestimating the risks of warming than overestimating them.
The American Meteorological Society issued its annual study of extreme weather events and said that many of those it studied this year would not have been possible without the influence of human-caused greenhouse gas emissions.
The National Oceanic and Atmospheric Administration (NOAA) said recent melting of the Arctic was not moderating and was more intense than at any time in recorded history.
While 2017 may not have hit a global temperature record, it is running in second or third place, and on the heels of records set in 2015 and 2016. Talk of some kind of “hiatus” seems as old as disco music.
'A Deadly Tragedy in the Making'
Some of the strongest warnings in the Royal Society update came from health researchers, who said there hasn't been nearly enough done to protect millions of vulnerable people worldwide from the expected increase in heat waves.
"It's a deadly tragedy in the making, all the worse because the same experts are saying such heat waves are eminently survivable with adequate resources to protect people," said climate researcher Eric Wolff, lead author of the Royal Society update.
Atmospheric scientist Kevin Trenberth of the National Center for Atmospheric Research said climate science has progressed in all directions since the IPCC report was published in 2014. He works with a group of scientists trying to update the IPCC reporting process to make it more fluid and meaningful in real time.
"The need to build resilience is clear and missing in action," Trenberth said. "The result is we suffer the consequences at costs of hundreds of billions of dollars." One of the starkest conclusions of the Royal Society update is that up to 350 million people in places like Karachi, Kolkota, Lagos and Shanghai are likely to face deadly heat waves every year by 2050—even if nations are able to rein in greenhouse gas emissions enough to keep the average global temperature increase to 1.5 degrees Celsius, as per the Paris climate agreement.
There's also an increasing chance global warming will affect a key North Atlantic current that carries ocean heat from the tropics toward western Europe, according to a 2016 study. It shows the Atlantic Meridional Overturning Current weakening by 37 percent by 2100, which could have big effects on European climate and food production.