Extreme weather and climate change: a new IPCC report
Extreme weather events are already being affected by human-caused climate change, and will increase in destructive power during the coming decades as huge cost, reported the United Nations Intergovernmental Panel on Climate Change (IPCC) today. The IPCC issues reports on the state of the scientific knowledge of climate change every six years, with the next full report due out in 2013. However, concern over the possible impact climate change may already be having on extreme weather events like heat waves, floods, and droughts prompted the IPCC to release their first-ever Special Report on Managing the Risks of Extreme Events and Disasters to Advance Climate Change Adaptation (SREX). The SREX report was divided into two sections: how human-caused climate change has already affected extreme weather events, and predictions on how these events will change during the rest of the century. Here are some highlights on how the climate has already changed, according to the SREX report:
- Globally, cold days and nights have decreased, and warm days and nights have increased (90 - 100% chance).
- In many but not all regions of the globe, the length or number of heat waves has increased.
- Some areas have seen more intense and longer droughts, in particular, southern Europe and West Africa. However, droughts have become less frequent, less intense, or shorter in some areas, such as central North America and northwestern Australia.
- Heavy precipitation events have changed in some regions. There is at least a 2-in-3 probability that more regions have seen increases than decreases in heavy precipitation events.
- The historical data base on hurricanes and tropical cyclones is not good enough to tell if they have changed.
- The jet stream has shifted towards the poles, meaning that the tracks of rain-bearing low pressure systems have also shifted towards the poles.
- Rising sea levels have led to an increase in extreme coastal flooding events (66 - 100% chance).
- Damage from extreme weather events has increased. Increases in population and wealth, and the fact more people are living in vulnerable areas, is a major cause of this increase in damage. It is uncertain if climate change is partially responsible for the increase in damage.
Figure 1. Predicted return periods for 1-day extreme precipitation events that occurred, on average, only once every 20 years between 1981-2000. A decrease in return period implies more frequent extreme precipitation events (i.e., less time between events on average). For Eastern North America, a 1-in-20 year heavy rain event is predicted to become a 1-in-7 to 1-in-9 year event by the end of the century, according to these climate model predictions. The box plots show results for regionally averaged projections for two time horizons, 2046 to 2065 and 2081 to 2100, as compared to the late-20th-century, and for three different emissions scenarios--a scenario where humans emit relatively little CO2 and other heat-trapping gasses (B1, blue bars), and two higher-emission scenarios (A1B and A2, green and red bars). Humanity is currently on a pace to emit more CO2 than the highest emission scenario shown here. Results are based on 14 climate models that contributed to the 2007 IPCC report. The level of agreement among the models is indicated by the size of the colored boxes (in which 50% of the model projections are contained), and the length of the whiskers (indicating the maximum and minimum projections from all models). Values are computed for land points only. The “Globe” inset box displays the values computed using all land grid points. Averaged over all areas of the globe, a 1-in-20 year heavy rain event is predicted to become a 1-in-8 to 1-in-12 year event by the end of the century. Image credit: The IPCC Special Report on Managing the Risks of Extreme Events and Disasters (SREX), 2011.
Here are some highlights of the forecasts for the future from the 2011 SREX report:
- A 1-in-20 year hottest day is at least 66% likely to become a 1-in-2 year event by the end of the 21st century in most regions, except in the high latitudes of the Northern Hemisphere, where it is likely to become a 1-in-5 year event.
- For Eastern North America, a 1-in-20 year heavy rain event is predicted to become a 1-in-7 to 1-in-9 year event by the end of the century.
- For Eastern North America, a maximum high temperature that occurred only once every 20 years during 1980 - 2000 is predicted to occur between once every three years and once per year by 2100.
- Extreme high temperature readings that occur once every 20 years will increase by 1°C to 3°C (1.8°F - 5.4°F) by mid-21st century and by about 2°C to 5°C (3.6°F - 9°F) by late-21st century.
- It is at least 66% likely that the frequency of heavy precipitation or the proportion of total rainfall from heavy falls will increase in the 21st century over many areas of the globe. This is particularly the case in the high latitudes and tropical regions, and in winter in the northern mid-latitudes. There is medium confidence that, in some regions, increases in heavy precipitation will occur despite projected decreases of total precipitation in those regions.
- Heavy rainfalls associated with tropical cyclones are at least 66% likely to increase with continued warming, and the maximum winds will increase. The total number of these storms is likely to remain about the same or decrease.
- There is medium confidence that droughts will intensify in the 21st century in some seasons and areas. Southern Europe and the Mediterranean region, central Europe, Central North America, Central America and Mexico, northeast Brazil, and southern Africa are at particular risk.
- In some regions, the main driver for increased damages from extreme weather events will not be climate change, but increases in population and wealth and vulnerability.
Intoducing climatecommunication.org
For those of you seeking detailed information on the research linking extreme weather events to climate change, I recommend a new website dedicated to improving communication of climate change information to the public, media, and policy makers, climatecommunication.org. The group is led by Susan Joy Hassol, a veteran climate change communicator, analyst, and author known for her ability to translate science into English, making complex issues accessible to policymakers and the public. Climatecommunication.org has put together an overview of extreme weather and climate change that I find a helpful resource when I am looking for the latest research results on the subject. I serve on their advisory board, along with a number of leading climate scientists.
Figure 2. Still image of the Bangkok, Thailand floods of October - November, 2011, as seen on the inaugural episode our new bi-monthly Extreme Weather video series.
Wunderground launches new Extreme Weather video series
Wunderground now features a new, twice-monthly Extreme Weather video series from GREEN.TV, with the latest reports and analysis on extreme weather around the world. From droughts to hurricanes to blizzards to flooding, Extreme Weather will cover the story and the science behind the events to try to understand their causes and consequences. The Extreme Weather series is sponsored by Vestas, the world's leading wind turbine manufacturer. The inaugural episode, launched yesterday, features video of the great Thailand flood, destructive floods in Italy, the $3 billion Northeast U.S. snowstorm of October 29 - 30, the massive Bering Sea, Alaska blizzard of November 9, the Texas drought, and the launch of a new polar-orbiting weather satellite. Look for a new video every two weeks on our Climate Change Videos page.
Resources
For those of you who haven't seen it, my top "must-read" post of 2011 is called, 2010 - 2011: Earth's most extreme weather since 1816?. Back in June, I went through the ridiculous barrage of extreme weather events the planet saw in 2010 and early 2011, and concluded: But it is highly improbable that the remarkable extreme weather events of 2010 and 2011 could have all happened in such a short period of time without some powerful climate-altering force at work. The best science we have right now maintains that human-caused emissions of heat-trapping gases like CO2 are the most likely cause of such a climate-altering force.
Wunderground's climate change blogger, Dr. Ricky Rood, has some thoughtful observations on the communication of the extreme weather/climate change link published in earthzine magazine titled, Changing the Media Discussion on Climate Change and Extreme Weather.
Jeff Masters
Reader Comments
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the Christmas tree comes from the bible
No. It's a pagan thing, too. From the ancient festival of Yule.
Now I can confirm you have never read the bible.
bodum chuuuhh
and the hits keep coming...
Will you give up the preaching already!!!!!!! Holy crap, this has gotten to be so annoying.
CaneWx, I agree with you completely. Discussing religion and other faith based topics on a science site should be considered rather off-topic. Still, everyone insists on discussing AGW in here like it was fact or something.
god help us all...
i am sorry if i have gone far with Christ. but i would stand up for Christ as long as i live. resume weather talk:)
I would, but it was told to me in Aramaic. It's been a long time since I spoke that one.
God wouldn't want you spreading lies either.
Google-ը ձեր ընկերն է.
Id rather not...
No! No! We wanted Brenda Lee!
Thanks, Geoff! I forgot to tell you that we had a silent vote. ;-)
Forecasted to go out to sea
No no no. Remember what we talked about regarding certainty in weather forecasting? ;)
You mean like most Christians?
Checking in on 99l;
Fight nice this eve - good night and good luck.
key word in that post was "Forecasted" lol
It's forecasted to go out to sea, will it actually?
If he wants to defend his faith, yes.
You said:
"Uh no"
;)
NWS NATIONAL HURRICANE CENTER MIAMI FL
100 AM EST MON NOV 21 2011
FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...
A BROAD LOW PRESSURE SYSTEM LOCATED ABOUT 850 MILES NORTHEAST OF THE
LEEWARD ISLANDS CONTINUES TO PRODUCE A LARGE AREA OF CLOUDINESS...
SHOWERS AND A FEW THUNDERSTORMS MAINLY TO THE NORTH AND EAST OF ITS
CENTER. THIS SYSTEM IS FORECAST TO STRENGTHEN AND PRODUCE
GALE-FORCE WINDS OVER THE NEXT COUPLE OF DAYS...AND IT IS POSSIBLE
THAT THE LOW COULD GRADUALLY ACQUIRE SUBTROPICAL CHARACTERISTICS
BEFORE IT MOVES OVER COOLER WATER. THIS SYSTEM HAS A MEDIUM
CHANCE...40 PERCENT...OF BECOMING A SUBTROPICAL CYCLONE DURING THE
NEXT 48 HOURS AS IT MOVES NORTH-NORTHEASTWARD AT 10 TO 15 MPH.
ADDITIONAL INFORMATION ON THIS LARGE WEATHER SYSTEM CAN BE FOUND IN
HIGH SEAS FORECASTS ISSUED BY THE NATIONAL WEATHER SERVICE...UNDER
AWIPS HEADER NFDHSFAT1 AND WMO HEADER FZNT01 KWBC.
Ah right, wasn't really paying attention to the conversation, just saw that comment
Holly Jolly Christmas would be nice ... btw Brenda rocks - g'nite
I did get a kick out of your comment, though. ;)
Never a bad thing, even though you don't believe something doesn't mean you shouldn't learn why other believe it.
glad someone did, didn't want to offend anyone although it was slightly offensive
How much of the Bible have you read, Tom?
Wishful thinking. ;)
Maybe not.
DECEMBER 3-6, 1886: Southern Appalachians
An early season heavy wet snowstorm hammered all of Alabama and the higher elevations of Georgia and North Carolina December 3-6, 1886 with 12-16" of snowfall in central Alabama (Montgomery had a record 11.0"), 17-20" in the northern parts of Alabama, and up to 25" in northern Georgia (as was measured in Rome). But it was in the mountains of North Carolina that the most extraordinary accumulations were reported with 36-42" at places like Hot House, North Carolina and Ducktown, Tennessee. Asheville, North Carolina reported 33" of snow on level, almost double the amount from the famous 'Superstorm' of 1993.
Huh, I hadn't heard of that one. Interesting.
I take it you've never believed in god then? I started off Christian but became atheist three years ago.
As far as religion, I like that it gives people something to believe in, something to have faith in, something to give them hope, but I can't stand most other aspects of it. The wars its caused, the control over the people through fear (fear of hell), the hypocrisy of it all, the fact that it has significantly prohibited scientific progression, the fact that it has very little basis in reality and was literally invented by man all annoy me.
As long as one is happy and not annoying me or others, I will respect their religion. If they try and force their viewpoints on others or deny science through religion, I will be quite annoyed.
Hehehe, try living in a family full of Christians.
That sounds rough though, what made you become a non believer?
Questions that couldn't be answered. That, and I've naturally been predisposed toward skepticism anyway. In hindsight, I never really was that serious with my faith, save for about a year in 2004. After I became an atheist, I was fiercely against religion (not just Christianity). I softened up after that, and although I still consider myself fairly mellow, I definitely despise religion now. Odd how much in circles I went.
Sorry to hear that about your brother.
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