BBC, Reuters, USA Today, Time link warming and extreme weather; Trenberth, Stott, and Masters explain the science
How hot is it? So hot that even the status quo media is waking up to the fact that human emissions of greenhouse gases are changing the climate and causing record-smashing extreme weather events, just as scientist predicted decades ago.
It happened to CNN meteorologist Chad Myers, and I have a roundup from other major media outlets — please add links to ones I missed.
At the end is a discussion of the science of Hell and High Water in pieces by NCAR’s Kevin Trenberth, The Met Office’s Peter Stott, and Jeff Masters — along with links for those who want to donate to help out in the “massive humanitarian crisis in Pakistan.” For more background, see “Intro to global warming impacts: Hell and High Water.”
Global climate change is partly to blame for the abnormally hot and dry weather in Moscow, cloaked in a haze of smoke from wildfires, say researchers.
The UK Met Office said there are likely to be more extreme high temperatures in the future….
Jeff Knight, a climate variability scientist at the UK Met Office, attributed the situation in Moscow to a number of factors, among them greenhouse gas concentrations, which are steadily rising.
Reuters (NYT): Analysis: Pakistan Floods, Russia Heat Fit Climate Trend
OSLO (Reuters) – Devastating floods in Pakistan and Russia’s heatwave match predictions of extremes caused by global warming even though it is impossible to blame mankind for single severe weather events, scientists say.
This year is on track to be the warmest since reliable temperature records began in the mid-19th century, beating 1998, mainly due to a build-up of greenhouse gases from fossil fuels, according to the U.N. World Meteorological Organization (WMO).
“We will always have climate extremes. But it looks like climate change is exacerbating the intensity of the extremes,” said Omar Baddour, chief of climate data management applications at WMO headquarters in Geneva….
Recent extremes include mudslides in China and heat records from Finland to Kuwait — adding to evidence of a changing climate even as U.N. negotiations on a new global treaty for costly cuts in greenhouse gas emissions have stalled.
Reinsurer Munich Re said a natural catastrophe database it runs “shows that the number of extreme weather events like windstorm and floods has tripled since 1980, and the trend is expected to persist.”
The worst floods in Pakistan in 80 years have killed more than 1,600 people and left 2 million homeless.
“Global warming is one reason” for the rare spate of weather extremes, said Friedrich-Wilhelm Gerstengarbe, a professor at the Potsdam Institute for Climate Impact Research.
He pointed to the heatwave and related forest fires in Russia, floods in Pakistan, rains in China and downpours in countries including Germany and Poland. “We have four such extremes in the last few weeks. This is very seldom,” he said.
The weather extremes, and the chance of a record-warm 2010, undercut a view of skeptics that the world is merely witnessing natural swings perhaps caused by variations in the sun’s output.
USA Today: Think this summer is hot? Get used to it
This summer’s stifling, deadly heat along the Eastern Seaboard and Deep South could be a preview of summers to come over the next few decades, according to a report about global warming to be published Wednesday by the National Wildlife Federation and the Asthma and Allergy Foundation of America.
In fact, according to NWF climate scientist Amanda Staudt, the summer of 2010 might actually be considered mild compared with the typical summers in the future. “We all think this summer is miserable, but it’s nothing compared to what’s in store for us,” she says.
The East just sweltered through one of its hottest Julys on record, the National Oceanic and Atmospheric Administration reported Monday. Every state from Maine to Florida endured one its top-10 warmest Julys since records began in 1880. Two states, Delaware and Rhode Island, had their hottest July ever.
The report, a supplement to a 2009 report on heat waves, notes that more extremely hot summer days are projected for every part of the country by the year 2050: “Summers like the current one, or even worse, will become the norm by 2050 if global warming pollution continues to increase unabated.”
A federal report by the U.S. Global Change Research Program in 2009, which much of this report was based on, found that average temperatures in the USA have increased more than 2 degrees Fahrenheit in the past five decades, largely as the result of emissions of heat-trapping greenhouse gases such as carbon dioxide, which are produced by burning fossil fuels.
Time (Walsh’s blog): The Asian Floods””Signs of Climate Catastrophes to Come?
NY Times (Revkin’s blog): Scientists See Links From Asian Floods to Russian Heat
Two climatologists, Peter Stott at the British Met Office and Kevin Trenberth of the National Center for Atmospheric Research, have separately described atmospheric dynamics that appear to link the extreme rains and flooding in Asia with Russia’s unrelenting, extraordinary heat and resulting conflagrations.
Peter Stott, head of climate monitoring and attribution at UK’s Met Office in UK Guardian: There have always been extremes of weather around the world but evidence suggests human influence is changing the odds:
Over the past week or so, Pakistan has been devastated by its worst floods for generations and Moscow has suffered under a blanket of smog after its hottest day in 130 years of records. What is causing these and other recent extreme weather events and are they linked to climate change?
Because of a rare meteorological pattern we can see a connection between extreme weather across Eurasia. Usually, the flow in the upper troposphere over northern India, the Himalayas and Pakistan is dominated by the monsoon anticyclone which pushes the sub-tropical jet to the north of the Tibetan Plateau. This prevents mid-latitude weather systems from penetrating very far south, unlike this year, when active weather systems have spread southwards into Pakistan. Here this has combined with the monsoon to produce record rainfall. The record-breaking high temperatures in Moscow, forest fires and damaged crops are another consequence, as was the excessive rain over China when the Three Gorges Dam almost reached capacity a few short weeks ago.
So are we seeing the effects of climate change in these extreme weather events? Analysing the observational data shows clearly that there has been a rise in the number of extremely warm temperatures recorded worldwide and that there have been increases in the number of heavy rainfall events in many regions over land. Evidence, including in India and China, that periods of heavy rain are getting heavier, is entirely consistent with our understanding of the physics of the atmosphere in which warmer air holds more moisture. Our climate change predictions support the emerging trend in observations and show a clear intensification of extreme rainfall events in a warmer world.
It can still be problematic to blame a specific individual extreme weather event on climate change, because there have always been extremes of weather around the world. However, if the likelihood of a particular extreme weather event has changed it is possible to say something. I and colleagues from Oxford University showed, in a paper we published in Nature, that the probability of the hot European temperatures in 2003 had very likely doubled as a result of human influence. While still relatively rare, the odds of such extreme events are rapidly shortening and could become considered the norm by the middle of this century.
Russia’s killer heat wave and monster South Asian monsoon floods could be more than isolated examples of extreme weather. Though separated by a continent, they could be linked.
Monsoon rains drive air upward, and that air has to come down somewhere. It usually comes down over the Mediterranean, producing the region’s hot, dry climate. This year, some of that air seems to have gone north to Russia.
“We haven’t done the studies, but there’s very good reason to suspect that there’s a relationship,” said Kevin Trenberth, head of climate analysis at the National Center for Atmospheric Research. “It’s simply related to the idea that there is a monsoon with very large circulation. There’s an upwards branch of it. There has to be a downwards branch somewhere else.”
The Russian heat wave has persisted since late June, with daytime temperatures at least 12 Fahrenheit degrees above normal “” and often much more “” for over a month. In Moscow alone, an estimated 300 people a day have died. The temperatures threaten wheat harvests and have sent global prices rising in a manner reminiscent of the lead-up to 2008’s global food riots.
Weather Underground meteorologist Jeff Masters called it “one of the most remarkable weather events of my lifetime,” which is probably an understatement. Russian meteorologists say it’s the most intense heat wave in a millennium.
Meanwhile, in South Asia and China, seasonal monsoons have been exceptionally intense, setting off the worst flooding in 80 years. Pakistan has been especially hard-hit, with 1,600 people dead and 2 million homeless in what’s been dubbed “Pakistan’s Katrina.”
Events like these fit with general forecasts of weather trends in a warming climate. But some observers have wondered whether Russia’s heat wave and Asia’s floods are linked not just by a vague trend, but by specific cause-and-effect meteorological dynamics. They will undoubtedly be studied in detail for years to come, but according to Trenberth, there’s good reason to think the extremes are connected.
“The two things are connected on a very large scale, through what we call an overturning or monsoonal circulation,” he said. “There is a monsoon where upwards motion is being fed by the very moist air that’s going onshore, and there are exceptionally heavy rains. That drives rising air. That air has to come down somewhere. Some of it comes down over the north.”Fueling the monsoons’ intensity are warmer-than-usual temperatures in and above the Indian Ocean. At 2 Fahrenheit degrees above late-20th century levels, the air can hold about 8 percent more water. At higher temperatures, the air is also more buoyant, and “invigorates the storms,” said Trenberth.
“Air rises faster than before. It sucks more air in. It changes moisture flow onto land even more. You can almost double the effect,” he said. “From that 8 percent more water, there can be 16 percent more rainfall.”