Heat waves to become more frequent and severe, research says

Aug 14, 2013
Formation of a heat wave. Credit: U. S. National Weather Service

Climate change is set to trigger more frequent and severe heat waves in the next 30 years regardless of the amount of carbon dioxide (CO2) we emit into the atmosphere, a new study has shown.

Extreme such as those that hit the US in 2012 and Australia in 2009—dubbed three-sigma events by the researchers—are projected to cover double the amount of global land by 2020 and quadruple by 2040.

Meanwhile, more-severe summer heat waves—classified as five-sigma events—will go from being essentially absent in the present day to covering around three per cent of the global land surface by 2040.

The new study, which has been published today, Thursday 15 August, in IOP Publishing's journal Environmental Research Letters, finds that in the first half of the 21st century, these projections will occur regardless of the amount of CO2 emitted into the atmosphere.

After then, the rise in frequency of extreme heat waves becomes dependent on the emission scenario adopted. Under a low emission scenario, the number of extremes will stabilise by 2040, whereas under a high emission scenario, the land area affected by extremes will increase by one per cent a year after 2040.

Lead author of the study, Dim Coumou, from the Potsdam Institute for Climate Impact Research, said: "We find that up until 2040, the frequency of monthly heat extremes will increase several fold, independent of the emission scenario we choose to take. Mitigation can, however, strongly reduce the number of extremes in the second half of the 21st century."

Under a high emission scenario, the projections show that by 2100, 3-sigma heat waves will cover 85 per cent of the global land area and five-sigma heat waves will cover around 60 per cent of global land.

"A good example of a recent three-sigma event is the 2010 heat wave in Russia, which expanded over a large area stretching from the Baltic to the Caspian Sea. In the Moscow region the for the whole of July was around 7°C warmer than normal—it was around 25°C. In some parts, temperatures above 40°C were measured," continued Coumou.

In their study, Dim Coumou, from the Potsdam Institute for Climate Impact Research, and Alexander Robinson, from Universidad Complutense de Madrid, used state-of-the-art climate models to project changes in the trend of heat extremes under two future warming scenarios—RCP2.6 and RCP8.5—throughout the 21st century. The historic period was also analysed, and the results showed that the models can accurately reproduce the observed rise in monthly heat extremes over the past 50 years.

Co-author of the study, Alexander Robinson, said: "Our three- and five-sigma thresholds are defined by the variability a region has experienced in the past, so the absolute temperatures associated with these types of event will differ in different parts of the world. Nonetheless these events represent a significant departure from the normal range of temperatures experienced in a given region."

According to the research, tropical regions will see the strongest increase in heat extremes, exceeding the threshold that is defined by the historic variability in the specific region. The results show that these changes can already be seen when analysing observations between 2000 and 2012.

"Heat extremes can be very damaging to society and ecosystems, often causing heat-related deaths, forest fires or losses to agricultural production. So an increase in frequency is likely to pose serious challenges to society and some regions will have to adapt to more frequent and more severe heat waves already in the near-term," continued Coumou.

Explore further: Nighttime heat waves quadruple in Pacific Northwest

More information: Historic and future increase in the global land area affected by monthly heat extremes, Dim Coumou and Alexander Robinson 2013 Environ. Res. Lett. 8 034018, iopscience.iop.org/1748-9326/8/3/034018/article

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NikFromNYC
1.8 / 5 (30) Aug 14, 2013
The 1930s Dust Bowl was much worse:

http://www.epa.go...aves.pdf

Computer model runs are not studies.

"Empirical evidence does not lend much support to the notion that climate is headed precipitately toward more extreme heat and drought. The drought of 1999 covered a smaller area than the 1988 drought, when the Mississippi almost dried up. And 1988 was a temporary inconvenience as compared with repeated droughts during the 1930s "Dust Bowl" that caused an exodus from the prairies, as chronicled in Steinbeck's Grapes of Wrath." James Hansen, 1999
NikFromNYC
1.7 / 5 (28) Aug 14, 2013
The NOAA specifically dispelled media hype about the 2012 drought by clearly stating it was not climate change related:

http://drought.go...ort-page

"...the signal of climate change may be very small compared to the noise of the intrinsic year-to-year variability. Detectability of a global warming signal in the statistics of summertime Great Plains rainfall may thus be very difficult at this time."

"Neither ocean states nor human-induced climate change, factors that can provide long-lead predictability, appeared to play significant roles in causing severe rainfall deficits over the major corn producing regions of central Great Plains."
MR166
1.8 / 5 (25) Aug 15, 2013
"Potsdam Institute for Climate Impact Research"

A suspicious person could guess the outcome of the research just from the name of the "institute" sponsoring it.
plaasjaapie
1.7 / 5 (23) Aug 15, 2013
Wow! The warmists are really going hysterical with allegations today! Here on the central coast of California the leaves of our maple trees have already gone yellow two months early. We're expecting an especially severe winter. :-(
Lurker2358
1.8 / 5 (21) Aug 15, 2013
According to the research, tropical regions will see the strongest increase in heat extremes, exceeding the threshold that is defined by the historic variability in the specific region. The results show that these changes can already be seen when analysing observations between 2000 and 2012.


Doubtful. The strongest increase in heat extremes is predictable by sea surface temperature anomalies, and the warmest SST anomalies in the northern hemisphere have been consistently occurring between about 40n and 55n, in both the pacific and the Atlantic, which is well outside the tropics.

The tropical atlantic and tropical pacific are currently about as average as anyone could expect them to be, with the eastern tropical pacific being slightly cooler than average, and because of the ITCZ pumping a constant stream of moisture between sea and land, I don't expect that land temperatures would rise any faster than water temperatures in the tropics anyway.

It's a ridiculous claim.
antialias_physorg
3.8 / 5 (13) Aug 15, 2013
Here on the central coast of California the leaves of our maple trees have already gone yellow two months early.

Weather. Climate. Please look up the difference before commenting on anything climate related.
NikFromNYC
1.5 / 5 (25) Aug 15, 2013
Weather. Climate. Please look up the difference before commenting on anything climate related.


"Psychological projection was conceptualized by Sigmund Freud in the 1890s as a defense mechanism in which a person unconsciously rejects his or her own unacceptable attributes by ascribing them to objects or persons in the outside world." - Wikipedia

See: "new normal."
MR166
1.7 / 5 (23) Aug 15, 2013
So Antialias how many years of stagnant/decreasing temperatures does it take for weather to become climate??? It seems that a relatively few hot summers is all that is needed to prove that the climate models are correct but how many years of stable to lowering world temperatures are needed to prove that this is just a temporary pause in a warming trend?

I ask this since it is obviously impossible to prove that the models are faulty by any possible changes in temperatures that could happen in ones lifetime.
Water_Prophet
1 / 5 (16) Aug 15, 2013
They say sooth, for Water's blessed avater, Ice has receeded from our nations and cannot be quickly recovered, even with most fevered prayers.
Blessed Ice can no longer cool the domains of man. See the wisdom of the authors in not blaming the Air Elemental CO2.
CO2 can grow many fold before it o'erwhelms the blessed Water.
If the number of droughts, or the curse of a lack of the blessed Element, per scores of years is increasing, then how is this not of climate?
antialias_physorg
4.1 / 5 (13) Aug 16, 2013
how many years of stagnant/decreasing temperatures does it take for weather to become climate???

Global vs. local is the issue, here. If you have local seasonal changes that tells you very little about global climate change. The bigger issue is energy content. Climate is a complex issue
You can even have a warming problem in a cooling era.
E.g. if you have a buffer system - like ice melting or methane hydrates sublimating. Then, beyond a certain temperature, you get energy taken from the atmosphere to fuel conversion from solid to liquid (or solid to gas in the case of methane hydrites). This takes energy - and seems to cool the atmosphere. BUT these buffer systems are limited - and acting as if climate change is suddenly not happening because of such a cooling observation is short-sighted (and extremely dumb).

But that is exactly what people who say "but we had a very cold winter" are doing. Being dumb.
antialias_physorg
4.1 / 5 (13) Aug 16, 2013
The Earth's surface is not uiform in temperature. Change of flow systems

Then there's the morons that say "we have seen cooling in X therefore there is cooling everywhere".

News flash: The Earth isn't uniform and there are atmospheric and ocean flow systems. Shifts in energy content shift these system, so that different regions will experience different WEATHER than before. This can even mean that some regions will see cooling. The cruicial thing to remember is that the AVERAGE energy content in the atmosphere is going up. (It's like winning the lottery: That you got more out of it than it cost you to buy a lottery ticket doesn't mean the lottery consortium is, on average, losing money)

As I said: This isn't science on the level of barroom talk. Climate science is heavy stuff. And I wish all these armchair coaches with half a brain cell and no education in statistics would stay out of it. They're only adding noise and showing off their lack of education.
Shootist
1.9 / 5 (23) Aug 17, 2013
"The polar bears will be fine". - Freeman Dyson.

Climate? For 500 years it was warm enough in Greenland for dairy farms. Since ~1350 CE it has been too cold. It is still too cold.

Climate? River Thames frost fairs were held on the tideway (held on the frozen river for those who can't read) of the River Thames at London between the 15th century and early 19th century, during the period known as the Little Ice Age, when the river froze over. It has been to warm since the early 1800s. The Thames no longer freezes at London.

The Little Ice Age followed the Medieval Climate Optimum. I can only expect that after the Little Ice Age ended, the climate warmed, again. And it has. All is as expected. Life is good. Warm temperatures for the next 1000 years or so, judging by the past 5000, anyway.
Gmr
3.5 / 5 (8) Aug 17, 2013
Weather. Climate. Please look up the difference before commenting on anything climate related.


"Psychological projection was conceptualized by Sigmund Freud in the 1890s as a defense mechanism in which a person unconsciously rejects his or her own unacceptable attributes by ascribing them to objects or persons in the outside world." - Wikipedia

See: "new normal."

Wow... projecting projection. We're in that other layer in "Inception" right?
hopper
1.9 / 5 (18) Aug 17, 2013

CO2 can grow many fold before it o'erwhelms the blessed Water.

Actually, recent studies have showed that increased CO2 has resulted in a greening of the deserts. Which would seem natural since CO2 is what plants breathe.http://news.inves...ener.htm
http://wattsupwit...ing-co2/
Egleton
3.5 / 5 (16) Aug 18, 2013
Am I to believe 97% of the Climatologists or a few wanna-be ranters?
Hmm. Lemme see. Tricky.
ubavontuba
1.7 / 5 (20) Aug 18, 2013
Am I to believe 97% of the Climatologists or a few wanna-be ranters?
Hmm. Lemme see. Tricky.
Consensus definition of global warming:

"global warming
n.
An increase in the average temperature of the earth's atmosphere, especially a sustained increase sufficient to cause climatic change."

Global temperatures: http://www.woodfo....5/trend

So what are you going to believe now?
ubavontuba
1.6 / 5 (19) Aug 18, 2013
Here on the central coast of California the leaves of our maple trees have already gone yellow two months early.

Weather. Climate. Please look up the difference before commenting on anything climate related.
Cold waves are weather and heat waves are climate, now? How does that work?
ScooterG
1.4 / 5 (20) Aug 18, 2013
Uba asked " Cold waves are weather and heat waves are climate, now? How does that work? "

You're demanding an absolute definition of "climate change" when none exists. A slippery definition helps perpetuate the AGW fraud.

Here's a vid of AL Gore recently rallying a few of the more intelligent AGW-faithful:

http://www.livele...76600179
Gmr
3.6 / 5 (14) Aug 18, 2013
Am I to believe 97% of the Climatologists or a few wanna-be ranters?
Hmm. Lemme see. Tricky.

Consider carefully! The wanna-be ranters have years of study of compartmentalized ignorance and multiple blogs at their disposal! You can't trust experts; just trust these guys - they're experts in not trusting ... oh, wait...
ubavontuba
1.4 / 5 (19) Aug 19, 2013
Uba asked " Cold waves are weather and heat waves are climate, now? How does that work? "

You're demanding an absolute definition of "climate change" when none exists. A slippery definition helps perpetuate the AGW fraud.
But there is an absolute consensus definition for global warming:

"global warming
n.
An increase in the average temperature of the earth's atmosphere, especially a sustained increase sufficient to cause climatic change."

Global temperatures: http://www.woodfo....5/trend

Hmm... maybe we should start checking the definitions for global cooling? LOL

ubavontuba
1.6 / 5 (21) Aug 19, 2013
Am I to believe 97% of the Climatologists or a few wanna-be ranters?
Hmm. Lemme see. Tricky.

Consider carefully! The wanna-be ranters have years of study of compartmentalized ignorance and multiple blogs at their disposal! You can't trust experts; just trust these guys - they're experts in not trusting ... oh, wait...
Typically ignorant AGWite believer, simply can't be bothered with facts.

Howhot
3.1 / 5 (7) Aug 20, 2013
Am I to believe 97% of the Climatologists or a few wanna-be ranters?
Hmm. Lemme see. Tricky.

Consider carefully! The wanna-be ranters have years of study of compartmentalized ignorance and multiple blogs at their disposal! You can't trust experts; just trust these guys - they're experts in not trusting ... oh, wait...
Typically ignorant AGWite believer, simply can't be bothered with facts.

Totally brainwashed droid anti-environmentalist, who ignores and distorts facts for his mental convenience and winger buds.
ubavontuba
1.5 / 5 (16) Aug 21, 2013
Totally brainwashed droid anti-environmentalist, who ignores and distorts facts for his mental convenience and winger buds.
Ha! Environmental protection is my profession.

What do you do for the environment?
antigoracle
1.3 / 5 (14) Aug 26, 2013
Still waiting for the more frequent and severe hurricanes and tornadoes as spouted by the same propaganda machine of the AGW Alarmist cult.
Just more fodder for the AGW chicken littles.
Neinsense99
2.1 / 5 (7) Aug 28, 2013
Totally brainwashed droid anti-environmentalist, who ignores and distorts facts for his mental convenience and winger buds.
Ha! Environmental protection is my profession.

What do you do for the environment?

Protecting the toxic environment that you and your ilk create here, perhaps.
Howhot
4.2 / 5 (5) Aug 28, 2013
Still waiting for the more frequent and severe hurricanes and tornadoes as spouted by the same propaganda machine of the AGW Alarmist cult.
Just more fodder for the AGW chicken littles.

Your too North America-centric. If you look at the typhoons on China, India, Australia they have been pretty powerful this year.
ubavontuba
1 / 5 (14) Aug 29, 2013
Totally brainwashed droid anti-environmentalist, who ignores and distorts facts for his mental convenience and winger buds.
Ha! Environmental protection is my profession.

What do you do for the environment?
Protecting the toxic environment that you and your ilk create here, perhaps.
What toxic environment are you protecting, where?

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