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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It is, but it's something I've deciphered for myself. No computer is going to think for me, especially when it comes to intensity forecasts. They fail more often than not.
(sarcasm flag):HIGH.
Congratulations! Excellent job. You have even created the opening scene for the next horror movie. ;-)
TS BUSTED FORECAST ALIBI
sup
well, I don't like horror movies but I'm glad you enjoyed the video :-)
sup kori, haha
Good evening.
Not much, writing a blog on TD13-E actually. You?
multivariable calc homework, and college football. Lots of upsets
The blogs I posted were blogs from actual scientists, who heavily sourced their material from multiple peer reviewed journal sources.
You have shown no such thing. You did no original research, you published in no journals. You posted a link to journal article where its own conclusion claimed a possible short timescale positive feedback from clouds that enhanced solar radiation changes. You also didn't seem to grasp that with solar irradiance currently decreasing, a positive feedback for reduced solar irradiance such as the one they suggested is actually evidence of a stronger enhanced greenhouse affect, because it would require more energy imbalance from greenhouse gases to overpower the solar feedback. Even if substantiated further, the 7 w/m^2 was not a sustained, growing amount as with greenhouse gases. It was range over a solar cycle of 11 years, peak-to-peak.
If you continue having difficulty understanding these items, yet continue claiming that you know more than 90% of climate scientists who have studied this issue far longer, then it would not be accurate to consider you an actual skeptic or scientist.
Clouds are rarely, if ever, considered a forcing. Just because a few scientists decided to call it as such does not make it so. Even somewhat skeptical scientists I know that are hesitant of climate models due to the need for better cloud modeling refer to clouds as feedbacks. The way you word it so authoritatively continues to show that you are not a skeptic.
Real simple.
Good job Kori, impressive as always
That is not science.
Thanks! You'll probably be seeing blogs on Tammy soon.
GCRs = galactic cosmic rays. Some research has suggested that galactic cosmic rays from the sun may help form clouds. But the mechanism by which this happens is not direct, and several things must happen.
1. GCRs must help form aerosols, then
2. The aerosols must grow to a size that is suitable as cloud-condensation nuclei
3. The condensation nuclei must then form cloud droplets.
Having condensation nuclei does not necessarily imply clouds will form. Some parts of the globe are saturated with nuclei, yet no clouds form due to insufficient moisture. Most GCRs also do not make it through the atmosphere.
The hypothesis is that increased cosmic rays lead to more cloud cover (cooling) and decreased cosmic rays lead to less cloud cover (warming). As one can see, several things must line up for this to work for clouds in a particular area, let alone the entire globe. It should also be noted that studies have shown very little trend in GCRs over the last several decades, and the slight trend found in some studies has actually been toward more GCRs (cooling) - the opposite of what would be required to cause the observed temperature changes.
http://www.skepticalscience.com/a-detailed-look-a t-galactic-cosmic-rays.html
For GCRs to be the dominant driver of climate change over the last several decades, proving the GCR mechanism would not be enough. One would also have to invalidate multiple lines of evidence from up to a century of research showing that greenhouse gases regulate the earth's temperature, and the dominant driver of climate today is greenhouse gases.
Just checked sat before your post and I think she will be born.
Loving the sat watching this one form.
A nice red herring. Your mind is only boggled because you are asserting something that isn't true.
The IPCC discusses observations heavily in their most recent reports. The observations are "unequivocal" that warming is happening, and very likely due to human activities. The measurements showing this to be true are there, for everyone to see. Just because you chose not to see them does not make them invisible. This doesn't work like playing peek-a-boo with a baby.
Nope. Just think for myself.
Let me know when there has actually been an increase since the prediction start of 2000.
Well, you don't have to because I track it... with raw data.
No need to argue, just need to observe.
Are you asserting otherwise?
Scientific method. Observe.
Ah! I am know beginning to understand your distrust of Science. ... You simply do not understand how Science works.
"Gravity", is a Scientific theory. A cheap shot, I realize, but, will suffice in the understanding of how Science works. The current Scientific theory of gravity best explains what we observe, for now. Should a better theory come along that better explains what we observe, then this will become the new Scientific theory of gravity. Sir Isaac Newton's theory of gravity stood the test of time until Albert Einstein came up with a new Scientific theory for gravity that better explains gravity. Even then, much of Newton's theory was retained. Einstein merely tweaked it to better explain gravity. Scientific theory is not fact. Scientific theory is the best explanation for what is being observed.
Perhaps this will help you? - Science
AGWT is the theory that best explains what we see concerning our global climate. Scientist have no other competing theory that better explains what is being observed about our global climate.
Do you believe that an object can be in two places at once? - Yes, it can be. - Another example. - This is the experiment I am familiar with.
Isn't Science a fascinating study?
And, you have no idea of what I accept, clearly.
What are your thoughts on string theory?
Anyway, goodnight.
We can easily observe gravity at work however, it can be tested. Unlike string theory, which can't be yet therefore it is a philosophy at this point.
I believe that string theory has its merits. Since it is as yet untestable, it is not a true science.
What do you mean by "observe"?
Scientist have observed a rise in atmospheric CO2 levels since the beginning of the Industrial Revolution. There is no other competing theory that explains this rise, in CO2 atmospheric concentrations, better than does the AGWT.
Scientist have observed, through tests, that CO2 behaves as an insulator in our atmosphere. The greenhouse effect.
Scientist have observed a warming to our atmosphere. There are no other competing theories that better explains this warming than does the AGWT.
Are you looking to observe a 10 foot rise in sea levels, a 10 degree rise in atmospheric global temperatures and mass extinctions as your "proof" of the AGWT?
"you have no idea of what I accept, clearly." - Clearly
Yes but, it takes a theory to explain what is being observed with gravity. Try to explain gravity without using any theories.
We have invest 99L.
INVEST, AL, L, , , , , 99, 2011, DB, O, 2011112006, 9999999999, , , , , , METWATCH, , AL992011
AL, 99, 2011111912, , BEST, 0, 223N, 524W, 25, 1013, LO
NWS NATIONAL HURRICANE CENTER MIAMI FL
700 AM EST SUN NOV 20 2011
FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...
SHOWER AND THUNDERSTORM ACTIVITY ASSOCIATED WITH A LOW PRESSURE
SYSTEM LOCATED ABOUT 550 MILES NORTHEAST OF THE NORTHEASTERN
LEEWARD ISLANDS HAS BECOME SLIGHTLY BETTER ORGANIZED DURING THE
LAST SEVERAL HOURS. CONTINUED SLOW DEVELOPMENT OF THIS DISTURBANCE
IS POSSIBLE DURING THE NEXT DAY OR TWO AS IT MOVES SLOWLY NORTHWARD
INTO A REGION OF MORE FAVORABLE UPPER-LEVEL WINDS. THIS SYSTEM HAS
A MEDIUM CHANCE...50 PERCENT...OF BECOMING A SUBTROPICAL OR
TROPICAL CYCLONE DURING THE NEXT 48 HOURS.
The following passage is from an about-to-be-published book on evolution, but for this conversation it could just as easily be talking about climate change:
"Scientists will tell you that most of the conceptual problem lies in the general public's misunderstanding of the word "theory". A scientific theory is not a hypothesis or guess, as the word commonly means when used in casual conversation. A scientific theory is the one explanation that is confirmed by all known and validated experiments performed to date. Experiments involving evolution have numbered in the hundreds of thousands over the past 150 year. A theory is thus among the most certain forms of scientific knowledge, and evolution is among the most certain of theories. But because science is inductive, scientists recognize that there is still a chance it could be wrong.
"In the case of evolution, the chance that it is wrong is somewhat smaller than that of, say, Earth being destroyed by a meteor in the next five minutes. We can see it working with our own eyes by watching viruses and bacteria evolve under the microscope. And biologists can show it to you so you can see it with your own eyes too, and when you do, it becomes difficult to see how anyone could construe it as a matter of "belief". It's like saying "I don't believe in gravity". It's ignorance of the evidence of observation."
--Otto, Shawn Lawrence. Fool Me Twice. Emmaus, PA: Rodale, 2011.
I think you're misinterpreting what I mean by "Cloud Forcing." Wiki has a nice page on it:
http://en.wikipedia.org/wiki/Cloud_forcing
Quote:
Cloud forcing (sometimes described as cloud radiative forcing) is, in meteorology, the difference between the radiation budget components for average cloud conditions and cloud-free conditions.
------------------------------------------------
Possibly two back-to-back seasons of 19 storms. Incredible.
Just five behind the collective total of 2004-05.
This AMO upswing (since '95) has shown to be really powerful or we really missed a lot more storms than first thought in earlier episodes.
For an excellent explanation, have a look here: Water vapour: feedback or forcing?
"While water vapour is indeed the most important greenhouse gas, the issue that makes it a feedback (rather than a forcing) is the relatively short residence time for water in the atmosphere (around 10 days)...Compared to the residence time for perturbations to CO2 (decades to centuries) or CH4 (a decade), this is a really short time."
Real Climate is run by scientists, but Skeptical Science is not.
Skeptical Science is run by a cartoonist who has no science degree.
Skeptical Science does use the peer reviewed literature, but they make their own conclusions off of the peer reviewed literature. Some conclusions that are different than the author of the paper's conclusions.
For example, With Palle 2004, SkS used that as evidence to show that albedo can not be driving Global Temperatures, because there was a spike in albedo in the Earthshine data, and no observed change was evident in the temperature data.
http://www.skepticalscience.com/earth-albedo-effe ct.htm
The authors themselves ruled 2003 to be anomalous, and possibly faulty.
Yes I have...
http://www.iac.es/galeria/epalle/reprints/Goode_P alle_JASTP_2007.pdf
http://lasp.colorado.edu/sdo/meetings/session_1_2 _3/presentations/session3/3_06_Palle.pdf
All old links from before.
TSI is not what makes Cloud Cover change, so I'm not sure what your main point here is.
I'm not sure how clouds decreasing on a Global scale is evidence of a stronger Greenhouse Effect... could you please explain?
We can clearly see though in ISSCP data that Cloud Cover changes do NOT follow an 11 year solar cycle, which is indicative that Clouds have a weak correlation to GCRs and the Solar AA Index. In addition, we do not have adequate data in the past to say that clouds have not been decreasing since the beginning of the 20th Century, and they, along with increasing TSI (until around 1980) could have continued to contribute all throughout the Century, alongside with CO2, the PDO/AMO Ozone etc.
I have not claimed that I know more than a climate scientist. The main reason why I want to debate with one, is to see if they can find any flaws in my argument, and I can patch up my argument, and help me learn some more.
If you convince me that most of Global Warming in the late-20th Century was anthropogenic, you will have yourself quite a strong ally ;)
This is a bit irrelevant, since I am refering to Clouds and not Water Vapour.
Irrational skeptics will try and claim that Water Vapour will "drive" temperatures, when it is clearly a feedback to increasing temperatures.
The issue that makes it a feedback (rather than a forcing) is the relatively short residence time for water in the atmosphere (around 10 days).[/Quote]
[Quote="Snowlover123"]
This is a bit irrelevant, since I am refering to Clouds and not Water Vapour.[/Quote]
Did you consider that if water residence time is around 10 days then cloud residence time is shorter again?
If 99L is named, that would give us Tammy and tie us with last year and the 3rd most active hurricane season ever.
Yeah, Science trumping Ideology..or the er, "Oz" factor you could say.
There is a Bunker available though..
LoL
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