Stanford climate scientists forecast permanently hotter summers

Jun 06, 2011

The tropics and much of the Northern Hemisphere are likely to experience an irreversible rise in summer temperatures within the next 20 to 60 years if atmospheric greenhouse gas concentrations continue to increase, according to a new climate study by Stanford University scientists. The results will be published later this month in the journal Climatic Change.

In the study, the Stanford team concluded that many regions in Africa, Asia and could see "the permanent emergence of unprecedented " in the next two decades. Middle latitudes of , China and North America – including the United States – are likely to undergo extreme summer temperature shifts within 60 years, the researchers found.

"According to our projections, large areas of the globe are likely to warm up so quickly that, by the middle of this century, even the coolest summers will be hotter than the hottest summers of the past 50 years," said the study's lead author, Noah Diffenbaugh, an assistant professor of environmental Earth system science and fellow at the Woods Institute for the Environment at Stanford. The study is co-authored by Stanford research assistant Martin Scherer.

"When scientists talk about global warming causing more heat waves, people often ask if that means that the hottest temperatures will become 'the new normal,'" Diffenbaugh said. "That got us thinking – at what point can we expect the coolest seasonal temperatures to always be hotter than the historically highest temperatures for that season?"

Climate models, past and future

To determine the seasonal impact of global warming in coming decades, Diffenbaugh and Scherer analyzed more than 50 model experiments –including computer simulations of the 21st century when global greenhouse gas concentrations are expected to increase, and simulations of the 20th century that accurately "predicted" the Earth's climate during the last 50 years. The analysis revealed that many parts of the planet could experience a permanent spike in seasonal temperatures within 60 years.

"We also analyzed historical data from weather stations around the world to see if the projected emergence of unprecedented heat had already begun," Diffenbaugh said. "It turns out that when we look back in time using temperature records, we find that this extreme heat emergence is occurring now, and that climate models represent the historical patterns remarkably well."

According to both the climate model analysis and the historical weather data, the tropics are heating up the fastest. "We find that the most immediate increase in extreme seasonal heat occurs in the tropics, with up to 70 percent of seasons in the early 21st century (2010-2039) exceeding the late-20th century maximum," the authors wrote.

may see the most dramatic changes first, but wide swaths of , and Mediterranean Europe are also likely to enter into a new heat regime by 2070, according to the study.

Environmental impact

This dramatic shift in seasonal temperatures could have severe consequences for human health, agricultural production and ecosystem productivity, Diffenbaugh said. As an example, he pointed to record heat waves in Europe in 2003 that killed 40,000 people. He also cited studies showing that projected increases in in the Midwestern United States could reduce the harvest of staples, such as corn and soybeans, by more than 30 percent.

Diffenbaugh was surprised to see how quickly the new, potentially destructive heat regimes are likely to emerge, given that the study was based on a relatively moderate forecast of greenhouse gas emissions in the 21st century.

"The fact that we're already seeing these changes in historical weather observations, and that they match climate model simulations so closely, increases our confidence that our projections of permanent escalations in seasonal temperatures within the next few decades are well founded," Diffenbaugh said.

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User comments : 16

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newsreader
4.3 / 5 (8) Jun 06, 2011

On the positive side its unlikely I'll live another 60 years.

On the negative side, if things really do get this bad we'll probably end up killing ourselves before that 60 year window is over.
3432682
1.7 / 5 (17) Jun 06, 2011
The global warming theory is wrong. The predictions have been falsified. The Earth is not warming as much as predicted, according to satellite surveillance; the seas are not rising as much as predicted; Antarctic ice is growing not shrinking; and the oceans are not warming, according to the ARGO ocean surveillance system. Changes in these measures are all within the range of normal, historic variation.

Earth temperatures were warmer for 90% of the last 10k years, and warmer 1k years ago, and 2k years ago. Current temperatures have warmed about 1F from the little ice age of 200-300 years ago, which was one of the few cool periods in the last 10k years.

Atmospheric humidity is falling not rising (from 1948 onward), thus gutting the central theory and prediction of greater greenhouse effect from increased water vapor. It is going in the wrong direction.

Computer models which predict from false theories are garbage in, garbage out. Back to the drawing boards.
Vendicar_Decarian
3.8 / 5 (13) Jun 06, 2011
"The global warming theory is wrong. The predictions have been falsified." - 3432Tard

Climate models make statistical predictions on the time scales of 30 years or so. Similarly Climate is measured on 30 year time scales. 30 year averages are what define climate.

What we know is that the climate models predict about a 1'C warming since industrialization and what we see is about a 1'C warming since industrialization.

Hence the climate models have correctly predicted the observed warming.

"Antarctic ice is growing not shrinking" -3432Tard

Now we know you are a liar.

Both Antarctic ice volume and Arctic ice volume are in decline.

"The team used measurements taken with the Gravity Recovery and Climate Experiment, or GRACE, to conclude the Antarctic ice sheet is losing up to 36 cubic miles of ice, or 152 cubic kilometers, annually." - University of Bolder Colorado

thermodynamics
3.6 / 5 (11) Jun 06, 2011
3432682: Are you a Luddite or just ill-informed? Where are your references? Do you expect anyone to accept a comment such as: "The global warming theory is wrong." You even contradict yourself when you say: "The Earth is not warming as much as predicted..." So, is it warming or not? As for predictions, which ones? What part of the globe? Please give us some references to back up claims like that.

You then claim that:: "Antarctic ice is growing not shrinking..."

Let's look at both of those claims with a reference:

http://www.nasa.g...les.html

So, in reality, both poles are warming - and faster than thought. So, show some support for your baseless claims.
newsreader
4.3 / 5 (6) Jun 06, 2011


...

So, in reality, both poles are warming - and faster than thought. ...


This is what I find most scary about our climate models. It seems like no matter how much we refine them, they always seem to underestimate the actual changes.
omatumr
1.4 / 5 (10) Jun 06, 2011
we're already seeing these changes in historical weather observations"


Dr. Ivanka Charvátová recalls the historical record of SIM (solar inertial motion) in a recent interview:

Already Sir Isaac Newton in his PRINCIPIA (1687) intuitively came to the following conclusion:

since that centre of gravity (centre of mass of the solar system) is continually at rest, the Sun, according to the various positions of the planets, must continually move every day, but will never recede far from that centre.

"This effect is not insignificant. The Sun moves across an area the size of 4.3 solar radiuses, i.e. 0.02 AU or 3.106 km. As a coincidence, the average solar speed is around 50 km/hr. Just like the speed of a car driving downtown."

"The first study about SIM was written by P.D. Jose in year 1965.

www.klimaskeptik....rom-gfu/

With kind regards,
Oliver K. Manuel
Sinister1811
3.3 / 5 (7) Jun 07, 2011
Global Warming skepticism arguments, and what the science really says.
http://www.skepti...ment.php
Vendicar_Decarian
3 / 5 (8) Jun 07, 2011
Sorry OmaTard, but the sun isn't a Neutron Star no matter how many times you say it.

"Dr. Ivanka Charvátová recalls the historical record of SIM (solar inertial motion) in a recent interview:.." - OmaTard

hush1
2 / 5 (4) Jun 07, 2011
Neither rhyme nor rhythm?
And you think this must be poetry.

Insanity is expecting a new answer every time you reboot your calculators.

You are not insane. You will get a new answer. Every time.
You are without expectation.
Nothing is a surprise.

Which leaves nothing of value.
Like climate.

Simply digress to newsreader.
And find what you seek.

Sinister1811
2.1 / 5 (9) Jun 07, 2011
Darn, why is my post the only one that doesn't get a rating? Oh well, I tried I guess.
hush1
2 / 5 (6) Jun 07, 2011
I rated you. I avoid rating as much as possible. And encourage others not to rate me.

Judging is directly proportional to happiness.
The smile. Any judge has. Do be fooled. By smiles.

:) <---------smiley (Are you fooled, yet?)
Sinister1811
2.1 / 5 (10) Jun 07, 2011
Whoever gave me the 1 rating is a dick. Pure and simple. If they bothered to read this, they would realize the REALITY of Global Warming, as opposed to the myths that they [choose] to believe.
http://www.skepti...ment.php
Javinator
3.5 / 5 (2) Jun 07, 2011
Whoever gave me the 1 rating is a dick.


Expect 1's when commenting on topics as "hot" as global warming (sorry, had to do it).

Also if you click your name and check your activity you can see who's been rating you.
Ethelred
4 / 5 (4) Jun 09, 2011
Dr. Ivanka Charvátová recalls the historical record of SIM
Indeed and if you use HER numbers unlike you get a different then she gives for the next long term minimum. She claims it should start cooling soon but HER numbers don't support that. Her own numbers show there should be a 30 to 50 year long minimum every 179 years between starts. Which is longer than her actual raw data shows.

The beginning of the most recent minumum, the Dalton Minimum (~1790-1840)
Average 1969
Earliest 1950
Latest 1980
So where is it? Its supposed to be every 179 years or thereabouts and last for 30 to 50 years. It didn't happen.

If a theory makes predictions that fail so badly that theory isn't a theory. It is just plain WRONG. Much like your claim of the Sun containing neutron star.

That is the short reply. I have replied to Oliver's latest crap source four times in long form. Three posts. Oliver hasn't had the guts to reply any of them.

Ethelred
3432682
1 / 5 (3) Jun 17, 2011
It will not do any good to provide references to the true believers in AGW. Approach the theory of GW with an open mind and do some actual research. You could begin with considering that we hear of no actual record-setting temperatures, except low temps. Consider which side is cooking the data, blocking publication of opposing views, and which side is getting all the money, even oil company money. Who composed the Hockey Stick, and did nothing when caught but create a new "spaghetti" version?
omatumr
1 / 5 (3) Jun 17, 2011
The climate scandal is now unfolding rapidly:

See Questions the IPCC must now urgently answer by Mark Lynas

www.marklynas.org...-answer/

See: "An opening mind. Part II" by Professor Curry

http://judithcurr...part-ii/

With kind regards,
Oliver K. Manuel
Former NASA Principal
Investigator for Apollo

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