Scientists Say Ongoing Weather Extremes Offer Proof of Climate Change
The bizarre weather of early summer in the US – from heatwave, wildfires, drought to freak storms – is just a sampling of what is to come for 2012 and a window to the future under climate change, scientists have said.
Scientists are wary of linking specific weather events to climate change, and this year's punishing heat and deadly thunder storms have been confined to the Americas. Europe, Asia and Africa haven't experienced severe weather this year – though they have in past years.
But the run of extreme weather offers real-time proof of the consequences of climate change, said Kevin Trenberth, who heads climate research at the National Centre for Atmospheric Research in Colorado – itself the scene of devastating wildfires.
"We are certainly seeing climate change in action," he said. "This year has been exceptionally unusual throughout the United States."
Jeff Masters director of meteorology at the Weather Underground website, told Democracy Now: "What we're seeing now is the future. We're going to be seeing a lot more weather like this, a lot more impacts like we're seeing from this series of heat waves, fires and storms."
He added: "This is just the beginning."
The prime exhibit for the bizarre turn of weather is the current heat wave.
The month of June alone shattered some 3,215 records for daily maximum heat. Cities like St Louis were sweltering under five consecutive days of triple digit temperatures on Tuesday. Last Thursday the city registered 108 degrees fahrenheit, the highest temperature in nearly 60 years.
"Historically this is going to end up being one of the hottest Junes of all time," said Harold Brooks, a research meteorologist at the National Severe Storm Laboratory in Oklahoma.
The high temperatures were also hitting earlier this summer, he said. Heat waves ordinarily do not build up until July.
But this has been a year for record-breaking heat. Since the start of the year, the United States set more than 40,000 hot temperature records and fewer than 6,000 cold temperature records, according to the National Oceanic and Atmospheric Administration.
Ordinarily, scientists would expect those numbers to be about the same, but the hot temperature records were falling at a ratio of about 7-1.
Such volatile temperatures, early in the year, helped contribute to the conditions for the deadly derecho thunder storm which blew through the Washington DC area with hurricane-force winds, killing some 22 people. Brooks said it was one of the most powerful such storms in recent history.
On the other side of the country, meanwhile, extreme drought conditions across a vast swathe of the American west led to an outbreak of mega-fires in Arizona, Colorado, and New Mexico.
Colorado's fires, outside the cities of Colorado Springs and Boulder, have between them destroyed more than 650 houses.
And there was no relief in sight. Aside from pockets such as northern Minnesota, Washington state, and New England, temperatures across a vast swathe of the United States were heading to record hot temperatures, Brooks said.
The season has already raised public health concerns. At least three people, all in their 70s and 80s, have died in St Louis since last week because of heat-related illness, medical officials said.
In the greater Washington DC area, where power outages due to the furious thunderstorm deepened the effects of a heat wave, the authorities have opened cooling centres in schools and community centres for those without access to air conditioning.
"Watch out for a long hot summer," said Trenberth.