IPCC: Expect More -- and More Frequent -- Weather Extremes
Science panel: Get ready for extreme weather
The Associated Press, Nov. 18, 2011
WASHINGTON — Top international climate scientists and disaster experts meeting in Africa had a sharp message Friday for the world's political leaders: Get ready for more dangerous and "unprecedented extreme weather" caused by global warming.
Making preparations, they say, will save lives and money.
These experts fear that without preparedness, crazy weather extremes may overwhelm some locations, making some places unlivable.
The Nobel Prize-winning Intergovernmental Panel on Climate Change issued a new special report on global warming and extreme weather after meeting in Kampala, Uganda. This is the first time the group of scientists has focused on the dangers of extreme weather events such as heat waves, floods, droughts and storms. Those are more dangerous than gradual increases in the world's average temperature.
"We need to be worried," said one of the study's lead authors, Maarten van Aalst, director of the International Red Cross/Red Crescent Climate Centre in the Netherlands. "And our response needs to anticipate disasters and reduce risk before they happen rather than wait until after they happen and clean up afterward. ... Risk has already increased dramatically."
The report said "a changing climate leads to changes in the frequency, intensity, spatial extent, duration, and timing of extreme weather and climate events, and can result in unprecedented extreme weather and climate events." And it said that some — but not all — of these extreme events are caused by the increase of man-made greenhouse gases in the atmosphere.
"We face many challenges in the future," another study lead author, Chris Field of Stanford University, said in a news conference. Those include floods, drought, storms, and heat waves. Field said scientists aren't quite sure which will be the biggest threat to the world because disasters are weather extremes interacting with economics and where people live. Society's vulnerability to natural disasters, aside from climate, has also increased, he said.
Field told The Associated Press in an interview that "it's clear that losses from disasters are increasing. And in terms of deaths, "more than 95 percent of fatalities from the 1970s to the present have been in developing countries," he said.
Losses are already high, running at as much as $200 billion a year, said Michael Oppenheimer of Princeton University, a study author.
"Global warming is increasing the risk of disaster and already makes dealing with several types of disaster, like heat waves, more difficult. The risk will become greater as the future gets hotter," he said.
Science has progressed so much in the last several years that scientists can now attribute the increase in many of these types of extreme weather events to global warming with increased confidence, said study author Thomas Stocker at the University of Bern.
Scientists were able to weigh their confidence of predictions of future climate disasters and heat waves were the most obvious. The report said it is "virtually certain" that heat waves are getting worse, longer and hotter, while cold spells are easing.
What that means is the nasty heat wave that used to happen once every 20 years by mid-century will be once every five years and by the end of the century will be an every other year scorcher, Field and Stocker said.
The report said there is at least a two-in-three chance that heavy downpours will increase, both in the tropics and northern regions, and from tropical cyclones.
The 29-page summary of the full special report — which will be completed in the coming months — says that extremes in some unnamed regions at some point in the future can get so bad that they may need to be abandoned.
Unless the world changes the way it deals with vulnerability disasters and climate change, "there's going to be an increasing number of places where dealing with these disasters is going to be more and more difficult," van Aalst said in a telephone interview. And in those cases, sometimes the most sensible option, he said, "may be to leave those places."
Such locations are likely to be in poorer countries, he said, but the middle class may be affected in those regions, which aren't specifically identified in the report. And even in some developed northern regions of the world, such as Canada, Russia and Greenland, cities might need to move because of weather extremes and sea level rise from man-made warming, van Aalst said. In places like van Aalst's native Netherlands, citizens will have to learn how to handle new weather problems, in this case heat waves.
Scientists emphasized that governments have to be more prepared.
"Governments are not doing a good job now protecting us from disaster in the current climate," Oppenheimer said.
And it's not just the big headline grabbing disasters like a Hurricane Katrina or the massive 2010 Russian heat wave that studies show were unlikely to happen without global warming. At the Red Cross/Red Crescent they are seeing "a particular pattern of rising risks" from smaller events, van Aalst said.
Of all the weather extremes that kill and cause massive damage, he said, the worst is flooding.
There's an ongoing debate in the climate science community about whether it is possible and fair to attribute individual climate disasters to manmade global warming. Usually meteorologists say it's impossible to link climate change to a specific storm or drought, but that such extremes are more likely in a future dominated by global warming.
The panel was formed by the United Nations and World Meteorological Organization. In the past, it has discussed extreme events in snippets in its report. But this time, the scientists are putting them all together.
The next major IPCC report isn't expected until the group meets in Stockholm in 2013.
Copyright 2011 The Associated Press. All rights reserved.
World to be hit by more weather disasters, scientists say
Some locations will become 'increasingly marginal as places to live'
The Associated Press, Nov. 1, 2011
WASHINGTON — Freakish weather disasters — from the sudden October snowstorm in the Northeast U.S. to the record floods in Thailand — are striking more often. And global warming is likely to spawn more similar weather extremes at a huge cost, says a draft summary of an international climate report obtained by The Associated Press.
The final draft of the report from a panel of the world's top climate scientists paints a wild future for a world already weary of weather
catastrophes costing billions of dollars.
The report says costs will rise and perhaps some locations will become "increasingly marginal as places to live."
The report from the Nobel Prize-winning Intergovernmental Panel on Climate Change will be issued in a few weeks, after a meeting in Uganda.
It says there is at least a 2-in-3 probability that climate extremes have already worsened because of man-made greenhouse gases.
This marks a change in climate science from focusing on subtle changes in daily average temperatures to concentrating on the harder-to-analyze freak events that grab headlines, cause economic damage and kill people.
The most recent bizarre weather extreme, the pre-Halloween snowstorm, is typical of the damage climate scientists warn will occur — but it's not typical of the events they tie to global warming.
"The extremes are a really noticeable aspect of climate change," said Jerry Meehl, senior scientist at the National Center for Atmospheric Research. "I think people realize that the extremes are where we are going to see a lot of the impacts of climate change."
The snow-bearing Nor'easter cannot be blamed on climate change and probably isn't the type of storm that will increase with global warming, four meteorologists and climate scientists said.
They agree more study is needed. But experts on extreme storms have focused more closely on the increasing numbers of super-heavy rainstorms, not snow, NASA climate scientist Gavin Schmidt said.
The opposite kind of disaster — the drought in Texas and the Southwest U.S. — is also the type of event scientists are saying will happen more often as the world warms, said Schmidt and Meehl, who reviewed part of the climate panel report.
No studies have specifically tied global warming to the drought, but it is consistent with computer models that indicate current climate trends will worsen existing droughts, Meehl said.
Studies also have predicted more intense monsoons with climate change. Warmer air can hold more water and puts more energy into weather systems, changing the dynamics of storms and where and how they hit.
Thailand is now coping with massive flooding from monsoonal rains that illustrate how climate is also interconnected with other manmade issues such as population and urban development, river management and sinking lands, Schmidt said.
In fact, the report says that "for some climate extremes in many regions, the main driver for future increases in losses will be socioeconomic in nature" rather than greenhouse gases.
Killer heat
There's an 80 percent chance that the killer Russian heat wave of 2010 wouldn't have happened without the added push of global warming, according to a study published last week in the Proceedings of the National Academy of Sciences.
So while in the past the climate change panel, formed by the United Nations and World Meteorological Organization, has discussed extreme events in snippets in its report, this time the scientists are putting them all together.
The report, which needs approval by diplomats at the mid-November meeting, tries to measure the confidence scientists have in their assessment of climate extremes both future and past.
Chris Field, one of the leaders of the climate change panel, said he and other authors won't comment because the report still is subject to change. The summary chapter of the report didn't detail which regions of the world might suffer extremes so severe as to leave them marginally habitable.
The report does say scientists are "virtually certain" — 99 percent — that the world will have more extreme spells of heat and fewer of cold. Heat waves could peak as much as 5 degrees hotter by mid-century and even 9 degrees hotter by the end of the century.
Weather Underground meteorology director Jeff Masters, who wasn't involved in the study, said in the United States from June to August this year, blistering heat set 2,703 daily high temperature records, compared with only 300 cold records during that period, making it the hottest summer in the U.S. since the Dust Bowl of 1936.
By the end of the century, the intense, single-day, heavy rainstorms that now typically happen only once every 20 years are likely to happen about twice a decade, the report says.
The report said hurricanes and other tropical cyclones — like 2005's Katrina — are likely to get stronger in wind speed, but won't increase in number and may actually decrease. Massachusetts Institute of Technology meteorology professor Kerry Emanuel, who studies climate's effects on hurricanes, disagrees and believes more of these intense storms will occur.
And global warming isn't the sole villain in future climate disasters, the climate report says. An even bigger problem will be the number of people — especially the poor — who live in harm's way.
University of Victoria climate scientist Andrew Weaver, who wasn't among the authors, said the report was written to be "so bland" that it may not matter to world leaders.
But Masters said the basics of the report seem to be proven true by what's happening every day. "In the U.S., this has been the weirdest weather year we've had for my 30 years, hands down. Certainly this October snowstorm fits in with it."
Copyright 2011 The Associated Press. All rights reserved.
