Just as scientists confidently predicted last century(opens in a new tab), climate change is pushing weather to extremes all over the planet.
A new report, published Monday by the American Meteorological Society, again proves the point. The 100-page report assessed(opens in a new tab) 17 extreme weather events from 2017 -- including floods, droughts, and heat waves -- and determined global warming either significantly boosted the odds of these events, or simply made such extreme, often deadly events possible in the first place.
"We are in a world that is warmer than in the 20th Century, and we keep moving farther from that baseline," Martin Hoerling, a National Oceanic and Atmospheric Administration (NOAA) scientist who worked on the report, said at the 2018 American Geophysical Union conference on Monday.
"There are very few places escaping from the warming that is occurring on our planet today," Hoerling added.
For each extreme event, the report outlines just how much climate change increased its likelihood, which is a growing field of science known as attribution research(opens in a new tab).
And when it comes to heat waves, rain, and drought, scientists have a good handle on how climate change exacerbates these events, often by modeling the chances of extreme weather events in the absence of today's globally disrupted climate.
"These attribution studies are telling us that a warming Earth is continuing to send us new and more extreme weather events every year,” Jeff Rosenfeld, editor in chief of the Bulletin of the American Meteorological Society, said in a statement.
Extreme deluges
Of note, Earth's hydrological, or water systems, have been propelled to the extreme. One reason is simple: Warming temperatures mean more water vapor is loaded into the atmosphere. Specifically for every 1 degree Celsius (1.8 degrees Fahrenheit) of warming, the air can hold 7 percent more water(opens in a new tab). That can mean historic, prolonged deluges.
In the U.S., scientists pointed out deluges during the 2017 California winter that threatened to collapse(opens in a new tab) the state's largest reservoir (the Oroville Dam), and the most extreme rain event in the nation's history, Hurricane Harvey.
"No single storm (Oroville) or instantaneous precipitation rate (Harvey) was to blame; rather, the damages were caused by precipitation that did not seem to stop," the authors wrote.
The report also highlights severe 2017 flooding in Bangladesh, Peru and China.
In Bangladesh, for example, extreme rain fell for six straight days before the expected monsoon, or summer rainfall season, even began. Human-caused warming, the authors found, was 100 percent responsible for the unusual rainfall event.
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Heat, heat, heat
Heat waves, the number one natural killer(opens in a new tab) of humans, made a strong appearance in 2017 (and then again in 2018).
Since the onset of the Industrial Revolution in the mid-1800s, climate change has boosted(opens in a new tab) the average global temperature by 1.8 degrees Fahrenheit, or 1 degree Celsius. This background warming makes typical heat waves all the more extreme, resulting in record heat.
"I’m virtually certain that nearly all heat waves have been made more severe by climate change," Michael Wehner, a senior scientist at the U.S. Department of Energy's Lawrence Berkeley National Laboratory, said this summer amid a flurry of global heat waves.
In 2017, southern Europe experienced an "exceptional heat wave" which was nicknamed "Lucifer." Temperatures in the Balkans and Italy sustained in the triple-digits for days, records fell, and nighttime temperatures elsewhere exceeded over 85 degrees.
Such a scorcher is three times more likely than it was in more temperate 1950s, the authors conclude.
And while Europe burned, China did the same.
The northeastern portion of the country saw its hottest temperatures on record, as a sustained mass of warm air hovered over the vast region.
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The authors concluded that climate change, all the more enhanced by decreasing Arctic sea ice (which ultimately helped produce this block of warm air), were the environmental culprits.
While once rare, severe heat events in this part of China are now believed to have a one in five chance of happening during any given year.
Paralyzing Drought
A particularly harsh drought hit the Northern Great Plains of the U.S. in 2017 -- even threatening an essential ingredient in beer.
This event, which proved to be a billion dollar disaster(opens in a new tab), hit Americans with a double whammy. Hot temperatures dried out the soil, easily outpacing dismal, record-low rains.
After modeling different climate scenarios, researchers determined that this event was 1.5 times more likely under our current climate scenario, wherein the atmosphere is saturated with its highest levels of carbon dioxide in some 15 million years.
