Extreme weather and climate change: a new IPCC report

By: Dr. Jeff Masters , 3:48 PM GMT on November 18, 2011

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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

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Quoting Seastep:


Yeah, and?

Let's see if the theory holds. Good luck.

If temps are flat for the next 30-40 years, would you still believe it?

And, for your "do something," what is that?

Would you be happy if all power were wind and solar?


Speaking for myself, I would be extremely elated!

I would be more than satisfied to learn that CO2 is not actually a greenhouse gas and we can dump all we want into the atmosphere. We still have a problem though. Once atmospheric CO2 hits 800 ppm, we will have great difficulty breathing. Perhaps this too will magically become a non issue?
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TT

Would you be happy if all power were wind and solar?
Member Since: September 9, 2008 Posts: 6 Comments: 3414
208. TomTaylor

For your BTW, yes, that is in the propaganda playbook.

Amazing that people actually accept a theory as fact without observational verification. Truly boggles my mind, but hey, it is the educational system we live in.

(not my kids)
Member Since: September 9, 2008 Posts: 6 Comments: 3414
Quoting TomTaylor:
Funny, what is the definition of climate?

Average weather conditions/observations over a 30 year or longer period. Never knew we had decided to make it 11 years.


Regardless, the Earth is still warming and man is still partially responsible. Shouldn't that be enough to realize that we probably should do something now?


Yeah, and?

Let's see if the theory holds. Good luck.

If temps are flat for the next 30-40 years, would you still believe it?

And, for your "do something," what is that?

Would you be happy if all power were wind and solar?
Member Since: September 9, 2008 Posts: 6 Comments: 3414
Quoting Seastep:


Funny. What is the trend since the 2000 predictions?

Trot out your "post-diction" vs. prediction all you want. Means zilch.
Funny, what is the definition of climate?

Average weather conditions/observations over a 30 year or longer period. Never knew we had decided to make it 11 years.


Regardless, the Earth is still warming and man is still partially responsible. Shouldn't that be enough to realize that we probably should do something now?


BTW, thanks for validating that graph NEA posted, lmao. You did literally exactly what the graph said skeptics do.
Member Since: August 24, 2010 Posts: 19 Comments: 4357
x
Member Since: August 24, 2010 Posts: 19 Comments: 4357
Quoting TomTaylor:
Great graphic lol

here it is again



Funny. What is the trend since the 2000 predictions?

Trot out your "post-diction" vs. prediction all you want. Means zilch.
Member Since: September 9, 2008 Posts: 6 Comments: 3414
Quoting TampaSpin:
Sure appears most of the peeps on this blog must be part of the "We the 99% groupies"! Just read all the comments today....funny as hell and what a bunch of GW bull to say everything has been extreme. ROFLMAO


Call it extreme, call it normal, call it what you want, that's your personal interpretation. One thing that remains a fact is that all of our scientific evidence shows that the globe is warming and that we are responsible to some extent.

Let me know if you ever find a lick of evidence showing that humans aren't in fact partially responsible or that the globe isn't warming. Until that time you'll just have to put up with science, or as you call it, "GW bull."
Member Since: August 24, 2010 Posts: 19 Comments: 4357
Quoting jazzie:
Late in saying this, but welcome back Dr. Grother.
Your humour and twit uhh wit has been missed.


Hey, jazzie! Haven't seen you in a while either.
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Quoting Neapolitan:

Well, of course not all charts and graphs are equal; it's much more fair to draw conclusions from an event with an 18-year duration than it is one that lasted just 10 or 11 months or so. But that's my point. Why highlight an 11-month decrease on a graph that otherwise shows a fairly steep increase over the past 220 months or so?

Here's a great animated graph from Skeptical Science that highlights what I'm talking about:

Ooops
Great graphic lol

here it is again

Member Since: August 24, 2010 Posts: 19 Comments: 4357
Fun evening. Thanks all.

Never trust a scientist who thinks they have it all figured out, especially on a new theory. More fail than do not. Although fail is a bit harsh. Many of those "failures" have components that are valid and advance science.

And, never trust anyone that says "I am from the government and I am here to help." Run the other way.

Credit to Reagan for the quote.

Goodnight.
Member Since: September 9, 2008 Posts: 6 Comments: 3414
From the EYW discussion today ...

.CLIMATE...
ON THIS DATE IN KEYS WEATHER HISTORY...IN 1941...2.03 INCHES OF RAIN
FELL IN KEY WEST. THIS SET THE DAILY RECORD FOR MAXIMUM RAINFALL
MEASURED IN KEY WEST ON NOVEMBER 18TH...A RECORD WHICH STILL STANDS
70 YEARS LATER. RAINFALL RECORDS IN KEY WEST DATE BACK TO 1871.
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Quoting Grothar:


I don't know. I have been so corny sometimes, I wanted to report myself.


Self reporting?
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Quoting Some1Has2BtheRookie:


I would hate to think that there is not anything that could travel faster than light but, confirming this will be somewhat, shall we say, astronomical in itself. Absolutely precise distances measured through Earth's crust and two clocks that are perfectly synchronized. Not an easy test to duplicate, I would think.


Its been said to be false, because they used different gps satellites
Member Since: September 6, 2007 Posts: 0 Comments: 6494
Late in saying this, but welcome back Dr. Grother.
Your humour and twit uhh wit has been missed.
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Quoting VAbeachhurricanes:


I could never do that to you groth ;)


I don't know. I have been so corny sometimes, I wanted to report myself.
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Quoting Seastep:
Nothing can travel faster than the speed of light, right?

Link


I would hate to think that there is not anything that could travel faster than light but, confirming this will be somewhat, shall we say, astronomical in itself. Absolutely precise distances measured through Earth's crust and two clocks that are perfectly synchronized. Not an easy test to duplicate, I would think.
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Quoting Grothar:


:)


I could never do that to you groth ;)
Member Since: September 6, 2007 Posts: 0 Comments: 6494
Quoting VAbeachhurricanes:


Re-ported.


:)
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Quoting VAbeachhurricanes:


Re-ported.


LOL.
Member Since: September 9, 2008 Posts: 6 Comments: 3414
Quoting Seastep:
Nothing can travel faster than the speed of light, right?

Link


You've never seen me on a Sunday night when I forget to put out the garbage.

Interesting article. The ramifications could be astounding.
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Quoting Grothar:


Come on now, I wasn't being surreptitious.


Stealthy English?
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Quoting Grothar:


Come on now, I wasn't being surreptitious.


Re-ported.
Member Since: September 6, 2007 Posts: 0 Comments: 6494
Quoting Seastep:
Nothing can travel faster than the speed of light, right?

Link


He probably just didnt hit the stop watch fast enough...
Member Since: September 6, 2007 Posts: 0 Comments: 6494
Quoting Some1Has2BtheRookie:


Not fair! We were speaking in English! ;-)


Come on now, I wasn't being surreptitious.
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Quoting VAbeachhurricanes:


He must get a check from dictionary.com


Should that be the case, I feel certain that he is being under paid! Sheeeeeeeez!
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Quoting caneswatch:


Look who's back again!


Look who's talking. Were you being held in abeyance?
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Nothing can travel faster than the speed of light, right?

Link
Member Since: September 9, 2008 Posts: 6 Comments: 3414
Quoting Grothar:


No, I just type after each heart beat. What do you expect Roger Bannister??


Nope! ... Roger Rabbit.
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Quoting Some1Has2BtheRookie:


Not fair! We were speaking in English! ;-)


He must get a check from dictionary.com
Member Since: September 6, 2007 Posts: 0 Comments: 6494
Quoting Grothar:


Some people are just more loquacious and garrulous than others.


Not fair! We were speaking in English! ;-)
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Quoting Some1Has2BtheRookie:
Grothar? ..... Are you on a 30 minute timer?


No, I just type after each heart beat. What do you expect Roger Bannister??
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Quoting Seastep:
How do you think that logic works with my wife?


I believe that "logic" is the operative word. A wife does not deal in logic. They only deal with results.
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Quoting Grothar:


That doesn't make any sense.


You don't make any sense! HA
Member Since: September 6, 2007 Posts: 0 Comments: 6494
Quoting Seastep:
How do you think that logic works with my wife?


Never said it worked all the time ;) just shouldnt apologize LOL
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Quoting VAbeachhurricanes:


Never apologize for that, the reason we have as many problems as we do is because people are so illogical.


That doesn't make any sense.
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Quoting Seastep:


Love it. Second word I had to look up today and I haven't had to look up a word in at least 10 years.

Got an email from a client today with "abeyance" in it.

Knew both generally, but had to double-check. Context worked on the latter, but checked to understand the context on the former.


Some people are just more loquacious and garrulous than others.
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Grothar? ..... Are you on a 30 minute timer?
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Quoting Grothar:


You sound like Spock.


Look who's back again!
Member Since: October 8, 2008 Posts: 14 Comments: 4553
How do you think that logic works with my wife?
Member Since: September 9, 2008 Posts: 6 Comments: 3414
Quoting Seastep:


Oh geez. Now even more so after my last post. :)

Sorry, I am a very logical person.


Never apologize for that, the reason we have as many problems as we do is because people are so illogical.
Member Since: September 6, 2007 Posts: 0 Comments: 6494
Quoting Grothar:


You sound like Spock.


Oh geez. Now even more so after my last post. :)

Sorry, I am a very logical person.
Member Since: September 9, 2008 Posts: 6 Comments: 3414
Quoting Grothar:


Oh, I've been popping in on the blog and saw the admonishments.


Love it. Second word I had to look up today and I haven't had to look up a word in at least 10 years.

Got an email from a client today with "abeyance" in it.

Knew both generally, but had to double-check. Context worked on the latter, but checked to understand the context on the former.
Member Since: September 9, 2008 Posts: 6 Comments: 3414
Quoting Grothar:


You sound like Spock.


The baby doctor?
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Quoting Seastep:
What happens if temps stay flat for 30-40yrs as they have since the predictions begin?

Or, *gasp*, go down?

Need to observe to see if the theory is correct. A theory can only become accepted after confirmation of the prediction.


You sound like Spock.
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Quoting Seastep:
What happens if temps stay flat for 30-40yrs as they have since the predictions begin?

Or, *gasp*, go down?

Need to observe to see if the theory is correct. A theory can only become accepted after confirmation of the prediction.


Then they will admit they were wrong, and keep being scientists on their merry way. (hopefully that is)
Member Since: September 6, 2007 Posts: 0 Comments: 6494
Quoting VAbeachhurricanes:


What do you think?


Oh, I've been popping in on the blog and saw the admonishments.
Member Since: Posts: Comments:
What happens if temps stay flat for 30-40yrs as they have since the predictions begin?

Or, *gasp*, go down?

Need to observe to see if the theory is correct. A theory can only become accepted after confirmation of the prediction.
Member Since: September 9, 2008 Posts: 6 Comments: 3414
Quoting VAbeachhurricanes:


Never realized we talked about the french...


I didn't have the nerve to write that one.
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Quoting Grothar:


Have you been behaving yourself?


What do you think?
Member Since: September 6, 2007 Posts: 0 Comments: 6494
Quoting TropicalAnalystwx13:

Frogs.


Never realized we talked about the french...
Member Since: September 6, 2007 Posts: 0 Comments: 6494

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Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.