Kyla Mandel / ThinkProgress & Damian Carrington /The Guardian – 2018-08-05 01:18:54
https://thinkprogress.org/climate-change-extreme-weather-heat-wildfire-record-events-fddc7bcd43a4/
Extreme Weather Just Caused a
Fire Tornado and the World’s Hottest Rainfall
Kyla Mandel / ThinkProgress
“We are now seeing the face of climate change.”
(August 4, 2018) — Unrelenting extreme weather is leading to some unprecedented and shocking events, including the hottest rainfall on earth and what many are calling a fire tornado.
This summer, much of the world has endured record-breaking heat — the type of which science tells us is what we can expect from climate change. In fact, scientists have already calculated July’s heatwave in Europe was made twice as likely by climate change.
“What we’re seeing right now across the Northern Hemisphere is extreme weather in the form of unprecedented heat waves, droughts, floods, wildfires,” climate scientist Michael Mann told the radio show Here & Now. “In isolation, it might seem like any one of these things could be dismissed as an anomaly, but it’s the interconnectedness of all these events and their extreme nature that tells us that we are now seeing the face of climate change. The impacts of climate change are no longer subtle.”
But the scorching heat isn’t just affecting temperatures on land anymore. It’s now heating up the ocean too. On August 2, the sea surface temperature measured by UC San Diego’s Scripps Institution of Oceanography — at its pier in La Jolla — reached 78.6 degrees Fahrenheit. This is the highest temperature reading in the pier’s 102-year history.
And last week at the end of July, we saw the hottest temperature ever measured while rain was falling. Temperatures reached 119°F in southern California near the US-Mexico border on July 24. At the same time clouds from the Gulf of California brought rain showers to the area. As the website Weather Underground wrote, this “sets a new record for the hottest rain in world history.”
Meanwhile, the Carr Fire near Redding California continues to expand; taking lives, destroying property, mangling metal, and charring the landscape. As of August 2, the fire has spread across more than 126,000 acres.
But on July 26, another extraordinary thing happened. That evening there was a sudden extreme, upwards expansion in the fire. This rapid vertical growth created an updraft, a so-called vortex of wind, which eventually created what looked like a tornado. According to estimates by the National Weather Service, this fire-tornado had winds exceeding 143 miles per hour — equivalent to an EF3 tornado, which is on the more intense side of the 0-5 scale.
“This is historic in the U.S.,” Craig Clements, director of San Jose State University’s Fire Weather Research Laboratory, told BuzzFeedNews. “This might be the strongest fire-induced tornado-like circulation ever recorded.”
This level of strong winds over such a large area is extremely rare in wildfires. But big fires are becoming more common. With rising global temperatures, when heat combines with dry periods or comes in semi-arid locations, water evaporates more quickly, and the soil becomes drier, ultimately creating conditions that can lead to wildfires — dried out shrubs and trees ignite more easily.
And while California and the west is no stranger to wildfires, the fire season now runs almost year-round, with 2018 already worse than previous seasons.
This week’s series of stunning events, however, wasn’t contained to the United States.
In Sweden, which has seen record hot Arctic temperatures, the country’s highest peak is melting away. A glacier which sits on top of the southern tip of the Kebnekaise mountain in northern Sweden is no longer considered the country’s tallest point scientists said on Wednesday. The peak — the height of which has been measured since 1880 — is set to be surpassed by another mountain in a range further north which is not covered in ice.
Scientists Find Heatwave Made More than
Twice as Likely by Climate Change
Fingerprints of global warming clear
after comparing northern Europe’s
scorching summer with records and computer models
https://www.theguardian.com/environment/2018/jul/27/heatwave-made-more-than-twice-as-likely-by-climate-change-scientists-find
Damian Carrington Environment editor /The Guardian
LONDON (July 27, 2018) — The heatwave searing northern Europe was made more than twice as likely by climate change, according to a rapid assessment by scientists.
The result is preliminary but they say the signal of climate change is “unambiguous”. Scientists have long predicted that global warming is ramping up the number and intensity of heatwaves, with events even worse than current one set to strike every other year by the 2040s.
“The logic that climate change will do this is inescapable – the world is becoming warmer, and so heatwaves like this are becoming more common,” said Friederike Otto, at the University of Oxford and part of the World Weather Attribution (WWA) consortium that did the work.
“What was once regarded as unusually warm weather will become commonplace, and in some cases, it already has,” she said. “So this is something that society can and should prepare for. But equally there is no doubt that we can and should constrain the increasing likelihood of all kinds of extreme weather events by restricting greenhouse gas emissions as sharply as possible.”
The new analysis is a climate-change attribution study. By comparing extreme weather with historical measurements and with computer models of a climate unaltered by carbon emissions, researchers can find how much global warming is increasing the risk of dangerous weather.
The researchers analysed records of the hottest three-day period at seven weather stations in northern Europe, from Ireland to the Netherlands to Scandinavia, where data was easily accessible.
“We found that for the weather station in the far north, in the Arctic Circle, the current heatwave is just extraordinary – unprecedented in the historical record,” said Geert Jan van Oldenborgh, at the Royal Netherlands Meteorological Institute and also part of WWA.
Across northern Europe, the group found global warming more than doubled the risk of scorching temperatures. “We can can see the fingerprints of climate change on local extremes,” he said. “It is amazing now that it is something you can really see at a local level.”
“Most heatwave studies have been done on large scale averages, so European-wide temperatures,” said Otto. “In this study, we have looked at individual locations, where people live, to represent the heatwave people are actually experiencing.” The analysis is a preliminary study as a full study requires many climate models to be run on high-powered computers, which takes months.
Previous attribution analyses have shown very strong connections between climate change and extreme weather events. The scorching summer in New South Wales, Australia, in 2016-17 was made at least 50 times more likely by global warming, meaning it can be “linked directly to climate change”, said the scientists.
The “Lucifer” heatwave across Europe’s Mediterranean nations in 2017 summer was made at least 10 times more likely by climate change, while the unprecedented deluge delivered in the US by Hurricane Harvey also in 2017 was made three times more likely by climate change, new research has found. However, other events, such as storms Eleanor and Friederike, which hit western Europe in January, were not made more likely by climate change, according to the scientists.
In Europe, the heatwave has been caused by the stalling of the jet stream wind, which usually funnels cool Atlantic weather over the continent. This has left hot, dry air in place for two months – far longer than than usual. The stalling of the northern hemisphere jet stream is being increasingly firmly linked to global warming, in particular to the rapid heating of the Arctic and resulting loss of sea ice.
The role of climate change in driving extreme weather events may actually be underestimated by these attribution studies, according to Prof Michael E Mann at Penn State University in the US. The work is good, he said, but computer models cannot yet reliably account for the complex jet stream changes caused by global warming, making the attribution studies “inherently conservative”.
Serious climate change is “unfolding before our eyes”, said Prof Rowan Sutton, director of climate research at the University of Reading. “No one should be in the slightest surprised that we are seeing very serious heatwaves and associated impacts in many parts of the world.”
The wide geographical spread of the heatwave, right across four continents, points to global warming as the culprit, said Prof Peter Stott, a science fellow at the UK’s Met Office: “That pattern is something we wouldn’t be seeing without climate change.”
The heatwave across northern Europe has seen wildfires in the Arctic Circleand prolonged heat across the UK and the European continent. In the south, fierce blazes have devastated parts of Greece, with scores of people killed.
But extreme weather has struck across the globe. Severe floods killed at least 220 people in Japan in early July, with the nation then hit by an “unprecedented” heatwave that peaked at 41.1C and left 35,000 people in hospital. In the US, extreme heat in the west is feeding wildfires, with Yosemite national park being evacuated, while flooding is affecting the east.
Temperature records have also fallen in Taiwan, with a temperature of 40.3C in Tianxiang, and in Ouargla in Algeria’s Sahara desert, which reported a maximum temperature of 51.3C, the highest temperature ever reliably recorded in Africa. The first six months of the 2018 are the hottest recorded for any year without an El Nino event, a natural climate cycle that raises temperatures.
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