human emissions fuel extreme weather, flooding that harm humans and the environment
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Two seminal Nature papers join growing body
of evidence that human emissions fuel
extreme weather, flooding that harm humans
and the environment
ByJoe Rommon Feb 16, 2011 at 5:12 pm
Here we show that human-induced increases in greenhouse gases
have contributed to the observed intensification of heavy
precipitation events found over approximately two-thirds ofdata-covered parts of Northern Hemisphere land areas. These
results are based on a comparison of observed and multi-model
simulated changes in extreme precipitation over the latter half of the
twentieth century analysed with an optimal fingerprinting technique.
Changes in extreme precipitation projected by models, and thus the
impacts of future changes in extreme precipitation, may be
underestimated because models seem to underestimate the
observed increase in heavy precipitation with warmingThats from the first of two seminal studies in Nature, Human
contribution to more-intense precipitation extremes (subs. reqd). The
second looked at Anthropogenic greenhouse gas contribution to flood
risk in England and Wales in autumn 2000 (subs. reqd):
Occurring during the wettest autumn in England and Wales since
records began in 1766 these floods damaged nearly 10,000 properties
across that region, disrupted services severely, and caused insuredlosses estimated at 1.3billion.
Here we present a multi-step, physically based probabilistic event
attribution framework showing thatit is very likely that global
anthropogenic greenhouse gas emissions substantially
http://thinkprogress.org/climate/2011/02/16/207545/two-nature-paper-join-growing-body-of-evidence-that-human-emissions-fuel-extreme-weather-flooding-that-harm-humans-and-the-environment/http://thinkprogress.org/climate/2011/02/16/207545/two-nature-paper-join-growing-body-of-evidence-that-human-emissions-fuel-extreme-weather-flooding-that-harm-humans-and-the-environment/http://thinkprogress.org/climate/2011/02/16/207545/two-nature-paper-join-growing-body-of-evidence-that-human-emissions-fuel-extreme-weather-flooding-that-harm-humans-and-the-environment/http://thinkprogress.org/climate/2011/02/16/207545/two-nature-paper-join-growing-body-of-evidence-that-human-emissions-fuel-extreme-weather-flooding-that-harm-humans-and-the-environment/http://thinkprogress.org/climate/2011/02/16/207545/two-nature-paper-join-growing-body-of-evidence-that-human-emissions-fuel-extreme-weather-flooding-that-harm-humans-and-the-environment/http://thinkprogress.org/climate/2011/02/16/207545/two-nature-paper-join-growing-body-of-evidence-that-human-emissions-fuel-extreme-weather-flooding-that-harm-humans-and-the-environment/http://thinkprogress.org/author/joe/http://thinkprogress.org/author/joe/http://thinkprogress.org/author/joe/http://www.nature.com/nature/journal/v470/n7334/full/nature09763.htmlhttp://www.nature.com/nature/journal/v470/n7334/full/nature09763.htmlhttp://www.nature.com/nature/journal/v470/n7334/full/nature09763.htmlhttp://www.nature.com/nature/journal/v470/n7334/full/nature09762.htmlhttp://www.nature.com/nature/journal/v470/n7334/full/nature09762.htmlhttp://www.nature.com/nature/journal/v470/n7334/full/nature09762.htmlhttp://www.nature.com/nature/journal/v470/n7334/full/nature09762.htmlhttp://www.nature.com/nature/journal/v470/n7334/full/nature09762.htmlhttp://www.nature.com/nature/journal/v470/n7334/full/nature09763.htmlhttp://www.nature.com/nature/journal/v470/n7334/full/nature09763.htmlhttp://thinkprogress.org/author/joe/http://thinkprogress.org/climate/2011/02/16/207545/two-nature-paper-join-growing-body-of-evidence-that-human-emissions-fuel-extreme-weather-flooding-that-harm-humans-and-the-environment/http://thinkprogress.org/climate/2011/02/16/207545/two-nature-paper-join-growing-body-of-evidence-that-human-emissions-fuel-extreme-weather-flooding-that-harm-humans-and-the-environment/http://thinkprogress.org/climate/2011/02/16/207545/two-nature-paper-join-growing-body-of-evidence-that-human-emissions-fuel-extreme-weather-flooding-that-harm-humans-and-the-environment/http://thinkprogress.org/climate/2011/02/16/207545/two-nature-paper-join-growing-body-of-evidence-that-human-emissions-fuel-extreme-weather-flooding-that-harm-humans-and-the-environment/ -
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increased the risk of flood occurrence in England and Wales in
autumn 2000.
in nine out of ten cases our model results indicate that
twentieth-century anthropogenic greenhouse gas emissions
increased the risk of floods occurring in England and Wales in
autumn 2000 by more than 20%, and in two out of three cases by
more than 90%.
Scientists have predicted for decades that human-caused global
warming would increased extreme weather events that cause severe
harm to humans, property, and the environment. These two studies are
but the latest in a growing body of scientific literature demonstrating
that these predictions are coming true now.
They should help lay to rest the myth that human-caused global
warming will contribute to grievous harm only in some far-off future.
They also strongly support the view that the human-induced increases
in greenhouse gases have contributed to the devastating extreme events
that hit Australia and other parts of the world in the past several
months, helping to drive up food prices (seehow extreme weather,
climate change drive record food prices).
The NYThas a great headline on this story, Research Links Heavy
Rains and Snow to Humans. It is all heavy precipitation that humans
are intensifying.
Of course, many of our top climate scientists have been documenting
and explaining these types of conclusions for a while. Ill list a bunch of
the papers below. Kevin Trenberth, head of NCARs Climate Analysis
Section, has a new paper out, Changes in precipitation with climate
change that is well worth reading. So I asked him for a comment on
these two studies. He told me:
These studies are very reasonable, and the main mechanism is well
understood: it relates to the increased moisture in the atmosphere with
higher temperatures and warmer oceans. However, the studies may
http://climateprogress.org/2011/01/20/lester-brown-extreme-weather-climate-change-record-food-prices/http://climateprogress.org/2011/01/20/lester-brown-extreme-weather-climate-change-record-food-prices/http://climateprogress.org/2011/01/20/lester-brown-extreme-weather-climate-change-record-food-prices/http://www.nytimes.com/2011/02/17/science/earth/17extreme.html?_r=1&partner=rss&emc=rss&pagewanted=printhttp://www.nytimes.com/2011/02/17/science/earth/17extreme.html?_r=1&partner=rss&emc=rss&pagewanted=printhttp://www.nytimes.com/2011/02/17/science/earth/17extreme.html?_r=1&partner=rss&emc=rss&pagewanted=printhttp://www.cgd.ucar.edu/cas/Trenberth/trenberth.papers/ClimateChangeWaterCycle-rev.pdfhttp://www.cgd.ucar.edu/cas/Trenberth/trenberth.papers/ClimateChangeWaterCycle-rev.pdfhttp://www.cgd.ucar.edu/cas/Trenberth/trenberth.papers/ClimateChangeWaterCycle-rev.pdfhttp://www.cgd.ucar.edu/cas/Trenberth/trenberth.papers/ClimateChangeWaterCycle-rev.pdfhttp://www.cgd.ucar.edu/cas/Trenberth/trenberth.papers/ClimateChangeWaterCycle-rev.pdfhttp://www.nytimes.com/2011/02/17/science/earth/17extreme.html?_r=1&partner=rss&emc=rss&pagewanted=printhttp://www.nytimes.com/2011/02/17/science/earth/17extreme.html?_r=1&partner=rss&emc=rss&pagewanted=printhttp://climateprogress.org/2011/01/20/lester-brown-extreme-weather-climate-change-record-food-prices/http://climateprogress.org/2011/01/20/lester-brown-extreme-weather-climate-change-record-food-prices/ -
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well be conservative as the tools available (the climate models), do not
simulate precipitation and all of its characteristics (intensity, frequency
etc) as well as we would like to see.
As the first study makes clear, future changes in extreme precipitation
are likely to be worse than the models suggest.
In anextended interviewlast year on the subject, Trenberth explained:
I find it systematically tends to get underplayed and it often gets
underplayed by my fellow scientists. Because one of the opening
statements, which Im sure youve probably heard is Well you
cant attribute a single event to climate change. But there is a
systematic influence on all of these weather events now-a-daysbecause of the fact that there is this extra water vapor lurking
around in the atmosphere than there used to be say 30 years
ago. Its about a 4% extra amount, it invigorates the storms, it
provides plenty of moisture for these stormsand its unfortunate
that the public is not associating these with the fact that this is one
manifestation of climate change. And the prospects are that these kinds
of things will only get bigger and worse in the future.
Lets hope these new studies helped put an end to the underplaying ofthe link between human caused emissions and the extreme weather
events we are experiencing now.
The Washington Post has a goodpieceon the two studies, Greenhouse
gases led to increase in deluges, researchers say, with more quotes:
Human influence on the climate system has the effect of intensifying
precipitation extremes, said Francis Zwiers, a climate researcher at
Environment Canada in Toronto and lead researcher on the first study.
Zwiers and his team gathered 50 years of rainfall statistics, and
compared those observations to predictions made by computer
simulations of the 20th century climate.
http://climateprogress.org/2010/06/14/ncar-trenberth-global-warming-extreme-weather-rain-deluge/http://climateprogress.org/2010/06/14/ncar-trenberth-global-warming-extreme-weather-rain-deluge/http://climateprogress.org/2010/06/14/ncar-trenberth-global-warming-extreme-weather-rain-deluge/http://voices.washingtonpost.com/post-carbon/2011/02/green_house_gases_led_to_incre.htmlhttp://voices.washingtonpost.com/post-carbon/2011/02/green_house_gases_led_to_incre.htmlhttp://voices.washingtonpost.com/post-carbon/2011/02/green_house_gases_led_to_incre.htmlhttp://voices.washingtonpost.com/post-carbon/2011/02/green_house_gases_led_to_incre.htmlhttp://climateprogress.org/2010/06/14/ncar-trenberth-global-warming-extreme-weather-rain-deluge/ -
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Those simulations included the warming impact of the billions of tons of
carbon dioxide human society has pumped into the atmosphere.
The study found that observed increase in deluges cannot be explained
by natural internal fluctuations of the climate system alone, saidZwiers. In other words, only the addition of greenhouse gases to the
atmosphere explains why the United States and Canada have
experienced a dramatic increase in heavy downpours.
Large [rainfall] events are becoming larger, Zwiers said. His work
found that from 1951 to 1999, the probability of heavy downpours
becoming even more extreme grew by about 7 percent, a figure he
characterized as really substantial.
Richard Allan, a climate scientist at the University of Reading in
England who was not part of the study, called the method employed by
Zwiers very rigorous.
He added, Theres already been quite a bit of evidence showing that
there has been an intensification of rainfall events across the globe.
But until now there had not been a study that formally identified thishuman effect on precipitation extremes, Zwiers said. This paper
provides specific scientific evidence that this is indeed the case.
Note that these studies do not extend beyond the year 2000, so they
miss the hottest decade on record and the wettest year on record.
You can see some of the amazing photos from the 2000 UK floodshere.
http://www.guardian.co.uk/environment/gallery/2011/feb/16/floods-2000-climate-change-pictures#/?picture=371763964&index=1http://www.guardian.co.uk/environment/gallery/2011/feb/16/floods-2000-climate-change-pictures#/?picture=371763964&index=1http://www.guardian.co.uk/environment/gallery/2011/feb/16/floods-2000-climate-change-pictures#/?picture=371763964&index=1http://www.guardian.co.uk/environment/gallery/2011/feb/16/floods-2000-climate-change-pictures#/?picture=371763964&index=1 -
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Heres some more quotes from leading scientists via Seth BorensteinsAPstory:
Both studies should weaken the argument that climate change is a
victimless crime, said Myles Allen of the University of Oxford. He co-
authored the second study, which connected flooding and climate
change in the United Kingdom. Extreme weather is what actually
hurts people.
Jonathan Overpeck, a University of Arizona climate scientist, who
didnt take part in either study, praised them as sensible and
particularly relevant given the array of extreme weather that weve
seen this winter and stretching back over the last few years.
Put the two papers together and we start to see an emerging
pattern, said Andrew Weaver of the University of Victoria, who wasnt
part of either study. We should continue to expect increased flooding
associated with increased extreme precipitation because of increasingatmospheric greenhouse gas. And we have no one to blame but
ourselves.
Lets run through some of the other recent studies that support the
conclusion that human-caused global warming is making weather more
extreme:
http://www.forbes.com/feeds/ap/2011/02/16/science-us-sci-climate-floods_8312043.htmlhttp://www.forbes.com/feeds/ap/2011/02/16/science-us-sci-climate-floods_8312043.htmlhttp://www.forbes.com/feeds/ap/2011/02/16/science-us-sci-climate-floods_8312043.htmlhttp://www.guardian.co.uk/environment/gallery/2011/feb/16/floods-2000-climate-change-pictures?picture=371763973http://www.forbes.com/feeds/ap/2011/02/16/science-us-sci-climate-floods_8312043.html -
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Study: Global warming is driving increased frequency of extreme wet or
dry summer weather in southeast, so droughts and deluges are likely to
get worse
A new study by a Duke University-led team of climate scientistssuggests that global warming is the main cause of a significant
intensification in the North Atlantic Subtropical High (NASH)
that in recent decades has more than doubled the frequency of
abnormally wet or dry summer weather in the southeastern
United States.
The modelsknown as Coupled Model Intercomparison Project Phase
3 (CMIP3) modelspredict the NASH will continue to intensifyand expand as concentrations of carbon dioxide and other
greenhouse gases increase in Earths atmosphere in coming
decades.This intensification will further increase the
likelihood of extreme summer precipitation variability
periods of drought or deluge in southeastern states in coming
decades, Li says.
And one of mycommentersposted this list in response to the
nonsensical quote by Pielke in the Wall Street Journal, Theres no
data-driven answer yet to the question of how human activity has
affected extreme weather. The first three may be the most relevant.
Some observational, modelling and observational and modelling studies
concerning the trends in temperature extremes and precipitation
intensity. I have limited myself to material that has been released since
2007 (when the last IPCC report was released); this is by no means a
complete list. Not all of them directly challenge the claim about human
activities affecting extreme weather, but I included them because theypoint to a coherent picture.
Zhang et al. (2007):Detection of human influence on twentieth-century
precipitation trends. (Nature)
We show that anthropogenic forcing has had a detectable
http://climateprogress.org/2010/10/28/global-warming-extreme-wet-dry-summer-weather-in-southeast-droughts-and-deluges/http://climateprogress.org/2010/10/28/global-warming-extreme-wet-dry-summer-weather-in-southeast-droughts-and-deluges/http://climateprogress.org/2010/10/28/global-warming-extreme-wet-dry-summer-weather-in-southeast-droughts-and-deluges/http://climateprogress.org/2010/10/28/global-warming-extreme-wet-dry-summer-weather-in-southeast-droughts-and-deluges/http://climateprogress.org/2011/02/11/the-world-bank-droughts-and-voodoo-economics/#comment-324978http://climateprogress.org/2011/02/11/the-world-bank-droughts-and-voodoo-economics/#comment-324978http://climateprogress.org/2011/02/11/the-world-bank-droughts-and-voodoo-economics/#comment-324978http://www.nature.com/nature/journal/v448/n7152/abs/nature06025.htmlhttp://www.nature.com/nature/journal/v448/n7152/abs/nature06025.htmlhttp://www.nature.com/nature/journal/v448/n7152/abs/nature06025.htmlhttp://www.nature.com/nature/journal/v448/n7152/abs/nature06025.htmlhttp://www.nature.com/nature/journal/v448/n7152/abs/nature06025.htmlhttp://www.nature.com/nature/journal/v448/n7152/abs/nature06025.htmlhttp://climateprogress.org/2011/02/11/the-world-bank-droughts-and-voodoo-economics/#comment-324978http://climateprogress.org/2010/10/28/global-warming-extreme-wet-dry-summer-weather-in-southeast-droughts-and-deluges/http://climateprogress.org/2010/10/28/global-warming-extreme-wet-dry-summer-weather-in-southeast-droughts-and-deluges/http://climateprogress.org/2010/10/28/global-warming-extreme-wet-dry-summer-weather-in-southeast-droughts-and-deluges/ -
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influence on observed changes in average precipitation within
latitudinal bands, and that these changes cannot be explained
by internal climate variability or natural forcing. We estimate
that anthropogenic forcing contributed significantly to observed
increases in precipitation in the Northern Hemisphere mid-latitudes,drying in the Northern Hemisphere subtropics and tropics, and
moistening in the Southern Hemisphere subtropics and deep tropics.
The observed changes, which are larger than estimated from model
simulations, may have already had significant effects on ecosystems,
agriculture and human health in regions that are sensitive to changes
in precipitation, such as the Sahel.
Christidis et al. (2011):The role of human activity in the recentwarming of extremely warm daytime temperatures. (J. Climate).
Our analysis is the first that attempts to partition the observed change
in warm daytime extremes between its anthropogenic and natural
components and hence attribute part of the change to possible causes.
Changes in the extreme temperatures are represented by the temporal
changes in a parameter of an extreme value distribution. Regional
distributions of the trend in the parameter are computed with and
without human influence using constraints from the global optimal
fingerprinting analysis.Anthropogenic forcings alter the regionaldistributions, indicating that extremely warm days have
become hotter.
Zwiers et al. (2010):Anthropogenic Influence on Long Return Period
Daily Temperature Extremes at Regional Scales.(J. Climate).
We therefore conclude that the influence of anthropogenic
forcing has had a detectable influence on extreme temperatures
that have impacts on human society and natural systems atglobal and regional scales. External influence is estimated to have
resulted in large changes in the likelihood of extreme annual maximum
and minimum daily temperatures. Globally, waiting times for extreme
annual minimum daily minimum and daily maximum temperatures
events that were expected to recur once every 20 years in the 1960s are
now estimated to exceed 35 and 30 years respectively. . In contrast,
http://journals.ametsoc.org/doi/abs/10.1175/2011JCLI4150.1http://journals.ametsoc.org/doi/abs/10.1175/2011JCLI4150.1http://journals.ametsoc.org/doi/abs/10.1175/2011JCLI4150.1http://journals.ametsoc.org/doi/abs/10.1175/2011JCLI4150.1http://journals.ametsoc.org/doi/abs/10.1175/2010JCLI3908.1http://journals.ametsoc.org/doi/abs/10.1175/2010JCLI3908.1http://journals.ametsoc.org/doi/abs/10.1175/2010JCLI3908.1http://journals.ametsoc.org/doi/abs/10.1175/2010JCLI3908.1http://journals.ametsoc.org/doi/abs/10.1175/2010JCLI3908.1http://journals.ametsoc.org/doi/abs/10.1175/2010JCLI3908.1http://journals.ametsoc.org/doi/abs/10.1175/2011JCLI4150.1http://journals.ametsoc.org/doi/abs/10.1175/2011JCLI4150.1 -
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waiting times for circa 1960s 20-year extremes of annual maximum
daily minimum and daily maximum temperatures are estimated to
have decreased to less than 10 and 15 years respectively.
Krishnamurthy et al. (2009): Changing Frequency and Intensity ofRainfall Extremes over India from 1951 to 2003. (J. Climate).
Statistically significant increasing trends in extremes of rainfall are
identified over many parts of India, consistent with the indications from
climate change models and the hypothesis that the hydrological cycle
will intensify as the planet warms. Specifically, for the exceedance of
the 99th percentile of daily rainfall, all locations where a significant
increasing trend in frequency of exceedance is identified also exhibit a
significant trend in rainfall intensity.
Teixeira and Satyamurty (2011): Trends in the Frequency of Intense
Precipitation Events in Southern and Southeastern Brazil during 1960-
2004. (J. Climate).
In both regions, annual heavy and extreme rainfall event frequencies
present increasing trends in the 45-year period. However, only in
Southern Brazil is the trend statistically significant. Although longer
time series are necessary to ensure the existence of long term trends,
the positive trends are somewhat alarming since they indicate thatclimate changes, in terms of rainfall regimes, are possibly under way in
Brazil.
Ding et al. (2009): Changes in hot days and heat waves in China during
1961-2007. (Int. J. Clim.)
Over most of China except northwestern China, the frequency of HDs
was high during the 1960s-1970s, low in the 1980s, and high
afterwards, with strong interannual variations. A remarkableincreasing trend of HDs occurred after the 1990s in all regions.
Rodda et al.(2009): A comparative study of the magnitude, frequency
and distribution of intense rainfall in the United Kingdom. (Int. J.
Clim).
Most noticeably, increases up to 20% have occurred in the north-west
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of the country and in parts of East Anglia. There have also been
changes in other areas, including decreases of the same magnitude over
central England. The implications of these changes are considered.
Kysel (2009): Recent severe heat waves in central Europe: how to viewthem in a long-term prospect? (Int. J. Clim).
Owing to an increase in mean summer temperatures, probabilities of
very long heat waves have already risen by an order of magnitude over
the recent 25 years, and are likely to increase by another order of
magnitude by around 2040 under the summer warming rate assumed
by the mid-scenario. Even the lower bound scenario yields a
considerable decline of return periods associated with intense heat
waves. Nevertheless, the most severe recent heat waves appear to betypical rather of a late 21st century than a mid-21st century climate.
Gallant and Karoly (2010): A Combined Climate Extremes Index for the
Australian Region (J. Climate)
Over the whole country, the results show an increase in the extent of
hot and wet extremes and a decrease in the extent of cold and dry
extremes annually and during all seasons from 1911 to 2008 at a rate of
between 1% and 2% decade21. These trends mostly stem from changes
in tropical regions during summer and spring. There are relationshipsbetween the extent of extreme maximum temperatures, precipitation,
and soil moisture on interannual and decadal time scales that are
similar to the relationships exhibited by variations of the means.
However, the trends from 1911 to 2008 and from 1957 to 2008 are not
consistent with these relationships, providing evidence that the
processes causing the interannual variations and those causing the
longer-term trends are different.
Romps (2011): Response of Tropical Precipitation to Global Warming.
(J. Atmos. Sci.)
There are many properties of convection that can change as the
atmosphere warms, each of which could produce deviations from CC
scaling. These properties include the effective water-vapor gradient,
cloud pressure depth, and cloud velocity. A simple theory is developed
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that predicts the changes in these properties consistent with CC
scaling. Convection in the cloud-resolving simulations is found to
change as predicted by this theory, leading to an ~20% increase in local
precipitation fluxes when the CO2 concentration is doubled. Overall, an
increase in CO2 leads to more vigorous convection, composed of cloudsthat are wider, taller, and faster.
Wentz et al. (2007): How Much More Rain Will Global Warming Bring?
(Science).
Climate models and satellite observations both indicate that the total
amount of water in the atmosphere will increase at a rate of 7% per
kelvin of surface warming. However, the climate models predict that
global precipitation will increase at a much slower rate of 1 to 3% perkelvin. A recent analysis of satellite observations does not support this
prediction of a muted response of precipitation to global warming.
Rather, the observations suggest that precipitation and total
atmospheric water have increased at about the same rate over the past
two decades.
Allan et al. (2010): Current changes in tropical precipitation.
(Environmental research letters).
Analysing changes in extreme precipitation using daily data within thewet regions, an increase in the frequency of the heaviest 6% of events
with warming for the SSM/I observations and model ensemble mean is
identified. The SSM/I data indicate an increased frequency of the
heaviest events with warming, several times larger than the expected
Clausius-Clapeyron scaling and at the upper limit of the substantial
range in responses in the model simulations.
Allan and sodden (2008): Atmospheric Warming and the Amplificationof Precipitation Extremes. (Science).
We used satellite observations and model simulations to examine the
response of tropical precipitation events to naturally driven changes in
surface temperature and atmospheric moisture content. These
observations reveal a distinct link between rainfall extremes and
temperature, with heavy rain events increasing during warm periods
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and decreasing during cold periods. Furthermore, the observed
amplification of rainfall extremes is found to be larger than that
predicted by models, implying that projections of future changes in
rainfall extremes in response to anthropogenic global warming may be
underestimated.
Lenderink and Meijgaard (2008) Increase in hourly precipitation
extremes beyond expectations from temperature changes. (Nature).
Indeed, changes in daily precipitation extremes in global climate
models seem to be consistent with the 7% increase per degree of
warming given by the Clausius-Clapeyron relation3, 4, but it is
uncertain how general this scaling behaviour is across timescales. Here,
we analyse a 99-year record of hourly precipitation observations fromDe Bilt, the Netherlands, and find that one-hour precipitation extremes
increase twice as fast with rising temperatures as expected from the
Clausius-Clapeyron relation when daily mean temperatures exceed
12C. In addition, simulations with a high-resolution regional
climate model show that one-hour precipitation extremes increase at a
rate close to 14% per degree of warming in large parts of Europe. Our
results demonstrate that changes in short-duration precipitation
extremes may well exceed expectations from the Clausius-Clapeyron
relation.
Of course, dont missTable 3.8in the IPCCs Fourth Assessment,
Working Group I: The Physical Science Basis.
Finally, we have one of my favorites,Record high temperatures far
outpace record lows across U.S.:
http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch3s3-8-5.html#table-3-8http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch3s3-8-5.html#table-3-8http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch3s3-8-5.html#table-3-8http://climateprogress.org/2010/02/11/science-meehl-ncar-record-high-temperatures-record-lows/http://climateprogress.org/2010/02/11/science-meehl-ncar-record-high-temperatures-record-lows/http://climateprogress.org/2010/02/11/science-meehl-ncar-record-high-temperatures-record-lows/http://climateprogress.org/2010/02/11/science-meehl-ncar-record-high-temperatures-record-lows/http://climateprogress.org/2010/02/11/science-meehl-ncar-record-high-temperatures-record-lows/http://climateprogress.org/2010/02/11/science-meehl-ncar-record-high-temperatures-record-lows/http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch3s3-8-5.html#table-3-8 -
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Spurred by a warming climate, daily record high temperatures occurred
twice as often as record lows over the last decade across the continental
United States, new research shows. The ratio of record highs to lows is
likely to increase dramatically in coming decades if emissions of
greenhouse gases continue to climb.
So yes, key weather events are becoming more extremeespecially
deluges, heat waves, and droughtsas climate scientists have long
predicted they would if atmospheric concentrations of greenhouse gases
kept rising. And now we have solid attribution of that increase in
extreme weather to human emissions in multiple independent studies.
So lets move on from that debate and focus on how we best minimize
the damage from future warmingaggressive greenhouse gas
mitigation plus adaptation.
http://www.ucar.edu/news/releases/2009/maxmin.jsphttp://www.ucar.edu/news/releases/2009/maxmin.jsphttp://www.ucar.edu/news/releases/2009/maxmin.jsphttp://www.ucar.edu/news/releases/2009/maxmin.jsphttp://www.ucar.edu/news/releases/2009/maxmin.jsphttp://www.ucar.edu/news/releases/2009/maxmin.jsphttp://www.ucar.edu/news/releases/2009/images/temps_2.jpghttp://www.ucar.edu/news/releases/2009/maxmin.jsphttp://www.ucar.edu/news/releases/2009/maxmin.jsphttp://www.ucar.edu/news/releases/2009/maxmin.jsphttp://www.ucar.edu/news/releases/2009/maxmin.jsphttp://www.ucar.edu/news/releases/2009/maxmin.jsp -
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Related Posts:
The year of living dangerously. Masters: The stunning extremeswe witnessed gives me concern that our climate is showing the
early signs of instability; Munich Re: The only plausibleexplanation for the rise in weather-related catastrophes is
climate change
Hansen: Would recent extreme events have occurred ifatmospheric carbon dioxide had remained at its pre-industrial
level of 280 ppm? The appropriate answer is almost certainly
not.
http://climateprogress.org/2010/12/23/the-year-of-living-dangerously-masters-weather-extremes-climate-change/http://climateprogress.org/2010/12/23/the-year-of-living-dangerously-masters-weather-extremes-climate-change/http://climateprogress.org/2010/12/23/the-year-of-living-dangerously-masters-weather-extremes-climate-change/http://climateprogress.org/2010/12/23/the-year-of-living-dangerously-masters-weather-extremes-climate-change/http://climateprogress.org/2010/12/23/the-year-of-living-dangerously-masters-weather-extremes-climate-change/http://climateprogress.org/2010/12/23/the-year-of-living-dangerously-masters-weather-extremes-climate-change/http://climateprogress.org/2010/10/01/hansen-extreme-events-2010-2012-record-high-global-temperature/http://climateprogress.org/2010/10/01/hansen-extreme-events-2010-2012-record-high-global-temperature/http://climateprogress.org/2010/10/01/hansen-extreme-events-2010-2012-record-high-global-temperature/http://climateprogress.org/2010/10/01/hansen-extreme-events-2010-2012-record-high-global-temperature/http://climateprogress.org/2010/10/01/hansen-extreme-events-2010-2012-record-high-global-temperature/http://climateprogress.org/2010/10/01/hansen-extreme-events-2010-2012-record-high-global-temperature/http://climateprogress.org/2010/10/01/hansen-extreme-events-2010-2012-record-high-global-temperature/http://climateprogress.org/2010/10/01/hansen-extreme-events-2010-2012-record-high-global-temperature/http://climateprogress.org/2010/10/01/hansen-extreme-events-2010-2012-record-high-global-temperature/http://climateprogress.org/2010/12/23/the-year-of-living-dangerously-masters-weather-extremes-climate-change/http://climateprogress.org/2010/12/23/the-year-of-living-dangerously-masters-weather-extremes-climate-change/http://climateprogress.org/2010/12/23/the-year-of-living-dangerously-masters-weather-extremes-climate-change/