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 TropicalAnalystwx13:
As some users have been advertising for a few days now, there could be a big Severe Weather/Tornado outbreak on Tuesday.


Likely this system will rear its head today.
SPC convective outlooks
Member Since: April 29, 2006 Posts: 159 Comments: 19393

000
ABNT20 KNHC 201738
TWOAT

TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
100 PM EST SUN NOV 20 2011

FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...

THERE HAS BEEN LITTLE CHANGE IN THE ORGANIZATION OF SHOWER AND
THUNDERSTORM ACTIVITY ASSOCIATED WITH A LOW PRESSURE SYSTEM LOCATED
ABOUT 600 MILES NORTHEAST OF THE NORTHEASTERN LEEWARD ISLANDS
DURING THE PAST SEVERAL HOURS. ENVIRONMENTAL CONDITIONS APPEAR
MARGINALLY CONDUCIVE FOR THE DEVELOPMENT OF THIS DISTURBANCE DURING
THE NEXT DAY OR SO AS IT MOVES SLOWLY NORTHWARD. THIS SYSTEM HAS A
MEDIUM CHANCE...50 PERCENT...OF BECOMING A SUBTROPICAL OR TROPICAL
CYCLONE DURING THE NEXT 48 HOURS.

ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.

$$
FORECASTER KIMBERLAIN
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Quoting TropicalAnalystwx13:
We probably have a tropical storm on our hands right now.


Looks around midgrade too.
I would put it at 45.
Member Since: October 22, 2011 Posts: 0 Comments: 2556
Wasn't the models protraying two storms to develope?
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Looking pretty darned good for November in the EPAC...
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Complete Update

TS BUSTED FORECAST ALIBI





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As some users have been advertising for a few days now, there could be a big Severe Weather/Tornado outbreak on Tuesday.

Member Since: July 6, 2010 Posts: 113 Comments: 32870
We probably have a tropical storm on our hands right now.

Member Since: July 6, 2010 Posts: 113 Comments: 32870
20/1145 UTC 23.0N 53.8W ST1.5 99L -- Atlantic
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Quoting Tazmanian:
i see we now have 99L

AL, 99, 2011112012, , BEST, 0, 223N, 537W, 25, 1010, LO,

You're a little late there.
Member Since: July 6, 2010 Posts: 113 Comments: 32870
i see we now have 99L

AL, 99, 2011112012, , BEST, 0, 223N, 537W, 25, 1010, LO,
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Link
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Quoting bohonkweatherman:
76 with 90 percent humidity here this morning, highs should be 68, lows should be in 40s. This weather is unreal and for most part we have been way too warm for November.


It got down to 78 here this morning. : )
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ri·dic·u·lous/riˈdikyələs/
Adjective:
Deserving or inviting derision or mockery; absurd.
Synonyms:
ludicrous - laughable - absurd - funny - comical


..er, for the "archive's" here
Member Since: July 3, 2005 Posts: 428 Comments: 129904
Lurking can't help myself... WE ALL HAVE OPINIONS you are going to argue about this some of this is rediculous y'all are being fools... Don't lose dignity over this, Remember this, 40 years ago we thought we were having a global cooling. There are a million and 1 factors that need to be looked at an we are probably on number 8, Who knows whats actually going on maybe there are emissions causing it or possible the earth's slightly fluxuating orbit, possibly less volcanic eruptions maybe or how land masses are effectingwind patterns which could cause global heating.... 100 million years ago the land was just so that it actually kept the earth MANY degrees warmer and almost no ice existed even at the poles. You sound like two year olds about this my bet is that in the next 30 years as our technology will advance so greatly that few fossil fuels will be needed get a clue... rant over
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Gotta run for now.

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76 with 90 percent humidity here this morning, highs should be 68, lows should be in 40s. This weather is unreal and for most part we have been way too warm for November.
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One for "some" to Bookmark,,maybe even read.

Steps of the Scientific Method


Even though we show the scientific method as a series of steps, keep in mind that new information or thinking might cause a scientist to back up and repeat steps at any point during the process. A process like the scientific method that involves such backing up and repeating is called an iterative process.
Member Since: July 3, 2005 Posts: 428 Comments: 129904
I think the Red Flag will go up soon....
Member Since: July 6, 2010 Posts: 113 Comments: 32870
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Quoting Seastep:
And, again, Nea, the past is irrelevant. The future is what is being predicted.

All that shows is, well, the past. Will it be a predictor of the future? Maybe. Maybe not.


No. The past is not irrelevant. The past helps us predict the future in many ways. It helps us establish the climate sensitivity. It helps us seen what things cause climate to change, and which forcings are strongest. It helps put our current predictions in context by showing what past changes have done to the world and it's ecosystems.
Member Since: September 28, 2002 Posts: 5 Comments: 3327
Quoting PensacolaDoug:
I don't make many typos. Nobody is 100%.


True dat.
Member Since: July 3, 2005 Posts: 428 Comments: 129904
[deleted duplicate post from modified comment]
Member Since: September 28, 2002 Posts: 5 Comments: 3327
Quoting Snowlover123:


What does Cloud Residence time have to do with Clouds decreasing as a whole since measurements began, and adding several w/m^2 of energy to Earth's Energy Budget while it was decreasing?


Because if the perturbation that had hypothetically changed atmospheric moisture went away today, within just a few short days, the moisture content would return to as it was.
For most greenhouse gases, their concentration would remain for decades, in not centuries.

Remember, again, that from your own source the hypothesized cloud reduction added a 7 w/m^2 enhancement to the solar cycle, it was not an addition to the energy budget over a long period as with well-mixed greenhouse gases.

I'm also starting to wonder why you have settled so strongly on "earthshine" as your indirect way of estimating cloud cover, when we have satellites pointed at the earth that can view them directly?
Member Since: September 28, 2002 Posts: 5 Comments: 3327
I don't make many typos. Nobody is 100%.
Member Since: July 25, 2006 Posts: 0 Comments: 670
Quoting ScottLincoln:




Statistical analysis does not include lines you drew on a graph in excel. Statistical analysis, like that done by statisticians, usually includes things like confidence intervals and uncertainty, and analysis of trends from noise.

Using the most recent temperature dataset, Berkely's BEST data, statistician Grant Foster illustrated the uncertainty bars in trends based upon their starting point. For statistical evidence that the trend has changed, the error bars must not include the trend line (red).

Even using 2005 as a starting point, the uncertainty in the data (noise vs. trend ratio) is such that there is no statistical evidence for a changed trend.


You are right. Statistically, it is all within the margin of error. i.e., no change. Even A1, I believe.

Which, again, begs the question, if it is all within the statistical margin of error, how can there be a consensus that spells doomsday?

Anyway. Theory has been posited, now we are observing to see if it holds. It either will or it won't.
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Member Since: July 3, 2005 Posts: 428 Comments: 129904
....well least ya can identify the "modify" one.

: )
Member Since: July 3, 2005 Posts: 428 Comments: 129904
Quoting Neapolitan:

If the past is irrelevant, why'd you bother putting it on your graph?


To show the shift.

Here's just 2000-2008, trend only. I'll do 2001-2011 when it comes in. The predictions start in 2000. Haven't gotten around to it since 2008 came in.



Modified: Actually that is 2001-2009. Just forgot to change the heading on that last frame, so it says 2005.
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Quoting Patrap:
196 regular days

Best try a real calender dere, sport.

And maybe try out the comment,er, "Preview" feature as well.

Double er, LoL



Oops. LOL!
I fixed it. I had a Rick Perry moment there.
Member Since: July 25, 2006 Posts: 0 Comments: 670
196 regular days?

Best try a real calender dere, sport.

Also a Math tutorial as well.

And maybe try out the comment,er, "Preview" feature as well.

Double er, LoL
Member Since: July 3, 2005 Posts: 428 Comments: 129904
Quoting Patrap:
There are now 396 Giorni days left till the 2012 Winter Solstice.

Enjoy yer Sunday.


Oddly enough, there are also 396 regular days till 2012 winter solstice as well.
I'm surely showing my ignorance as I don't have a clue about what "Giorni" days. But they surely do equal earth days. I can read a calendar and do simple math. LOL!
Member Since: July 25, 2006 Posts: 0 Comments: 670
Quoting Seastep:

Just for Nea, I am going to do GISS, too, after this year is over.

Yes, the decade is warmer, but not getting warmer. There is a difference.



Quoting ScottLincoln:
1. Using monthly timeseries data, it has been found that a 15yr or longer period is required in order to discern the long-term trend from natural variability.
2. Statistical analysis has also shown no evidence for a changed trend since 2000.


Statistical analysis does not include lines you drew on a graph in excel. Statistical analysis, like that done by statisticians, usually includes things like confidence intervals and uncertainty, and analysis of trends from noise.

Using the most recent temperature dataset, Berkely's BEST data, statistician Grant Foster illustrated the uncertainty bars in trends based upon their starting point. For statistical evidence that the trend has changed, the error bars must not include the trend line (red).

Even using 2005 as a starting point, the uncertainty in the data (noise vs. trend ratio) is such that there is no statistical evidence for a changed trend.
Member Since: September 28, 2002 Posts: 5 Comments: 3327
co2now.org


388.92ppm


Atmospheric CO2 for October 2011
Preliminary data released November 4, 2011
(Mauna Loa Observatory: Scripps Institution of Oceanography)
Member Since: July 3, 2005 Posts: 428 Comments: 129904
The "Past" easily shows the area of concern for "Now".


Carbon dioxide concentration (parts per million) for the last 800,000 years, measured from trapped bubbles of air in an Antarctic ice core. The 2008 observed value is from the Mauna Loa Observatory in Hawaii and projections are based upon future emission scenarios. More information on the data can be found in the Climate Change Impacts on the U.S. report.


Global Climate Change Indicators
National Oceanic and Atmospheric Administration
National Climatic Data Center
Member Since: July 3, 2005 Posts: 428 Comments: 129904
There are now 396 Giorni days left till the 2012 Winter Solstice.

Enjoy yer Sunday.
Member Since: July 3, 2005 Posts: 428 Comments: 129904
Quoting Seastep:
And, again, Nea, the past is irrelevant. The future is what is being predicted.

All that shows is, well, the past. Will it be a predictor of the future? Maybe. Maybe not.

I'm jumping into this conversation for a second, and I may be dead wrong, but how is the past irrelevant? The past deals a lot with the future.
Member Since: July 6, 2010 Posts: 113 Comments: 32870
Quoting Seastep:
And, again, Nea, the past is irrelevant. The future is what is being predicted.

All that shows is, well, the past. Will it be a predictor of the future? Maybe. Maybe not.

If the past is irrelevant, why'd you bother putting it on your graph?
Member Since: November 8, 2009 Posts: 4 Comments: 13805
Quoting Patrap:


Yeah, Science trumping Ideology..or the er, "Oz" factor you could say.

There is a Bunker available though..

LoL


Ya'll need a name.

How about "OCCUPY WUNDERGROUND"?


chuckle chuckle snort snort...
Member Since: July 25, 2006 Posts: 0 Comments: 670
And, again, Nea, the past is irrelevant. The future is what is being predicted.

All that shows is, well, the past. Will it be a predictor of the future? Maybe. Maybe not.
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Quoting Neapolitan:

Seriously? Why select 1998 as the start? Isnt that, as has been pointed out, rather arbitrary?

A question denialists must always be asking themselves: how can it be warming if it's almost always cooling?

uh-oh


Not arbitrary. There was a clear shift in 1998.

Ignore it if you'd like.
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Quoting Snowlover123:


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 is run by John Cook. He majored in physics/solar physics during both his undergrad and graduate years.

I attempted to find evidence of him not possessing a degree from those multiple years of schooling, including visits to varying degrees of skeptical and science denial websites and multiple pages of google search results from multiple search phrase choices. However I found nothing other than two comments on blogs, hinting at him being a "failed physics student." Usually failed physics students do not go on to graduate work. When looking at more authoritative sources, like interviews by universities, they refer to him graduating from University of Queensland or being a physicist from the University of Queensland.
Member Since: September 28, 2002 Posts: 5 Comments: 3327
Quoting Seastep:


Just for Nea, I am going to do GISS, too, after this year is over.

Yes, the decade is warmer, but not getting warmer. There is a difference.


Seriously? Why select 1998 as the start? Isnt that, as has been pointed out, rather arbitrary?

A question denialists must always be asking themselves: how can it be warming if it's almost always cooling?

uh-oh
Member Since: November 8, 2009 Posts: 4 Comments: 13805

QUOTE:
Clouds are considered a feedback by climate scientists, not a forcing. The difference in terminology is important.

The Solar AA Index changes----->GCR Flux------>Solar Cloud Feedback.

I know that changes in Cloud Cover are due to a feedback. A solar feedback to be exact. However, the Cloud Forcing is how much energy Clouds will add to Earth's Energy Budget if they were to be subtracted from Earth's Global Energy Flows.
Member Since: April 1, 2010 Posts: 9 Comments: 2699
The blog comments are messed up...
Member Since: April 1, 2010 Posts: 9 Comments: 2699
Quoting crandles:
Did you consider that if water residence time is around 10 days then cloud residence time is shorter again?


What does Cloud Residence time have to do with Clouds decreasing as a whole since measurements began, and adding several w/m^2 of energy to Earth's Energy Budget while it was decreasing?
Member Since: April 1, 2010 Posts: 9 Comments: 2699
ScottLincoln - Is it safe to assume your prediction is the IPCC A1 "business as usual" scenario, since that is still the current scenario?

Just want to make sure. Wouldn't want to put words in your mouth.

Edited to fix the scenario name.
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Quoting Snowlover123:
I have shown with observational evidence that the change in the Cloud Forcing has resulted in 7 w/m^2 being added to Earth's Energy Budget over a 21 year timeframe, compared to CO2 adding 1.4 w/m^2 since 1790 to Earth's Energy Budget. The cause of this change is due to an external factor such as the Solar AA Index inflicting changes upon GCRs rather than temperature.




No you haven't. You've shown evidence from discredited claims and research. Repeating it doesn't make it any more credible.
Member Since: October 31, 2009 Posts: 0 Comments: 1656
2011 should come in well below 2010 and probably 2009, too.

Might be pretty close to 2008. Haven't graphed it yet, just on look.
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Quoting Snowlover123:


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.
------------------------------------------------


You forgot the very next sentence from that source you cited:

"Much of the interest in cloud forcing relates to its role as a feedback process in the present period of global warming."

Clouds are considered a feedback by climate scientists, not a forcing. The difference in terminology is important.
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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.

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