NOAA Paper: North American 2008 Cooling Attributed to Natural Causes

Cool sea surface temperatures overrode warming

December 4, 2009

Left side: 1970-2007 trend in annual surface air temperature. Right sid: 2008 annual surface air temperature, shown as a departure from the 1971-2000 climatology.

Left side: 1970-2007 trend in annual surface air temperature. Right sid: 2008 annual surface air temperature, shown as a departure from the 1971-2000 climatology.

High resolution (Credit: NOAA)

Cooler North American temperatures in 2008 resulted from a strong natural effect, and the overall warming trend that has been observed since 1970 is likely to resume, according to university and NOAA scientists.

“Our work shows that there can be cold periods, but that does not mean the end of global warming. The recent coolness was caused by transitory natural factors that temporarily masked the human-caused signal,” said Judith Perlwitz, lead author of the study and a researcher with the Cooperative Institute for Research Environmental Sciences, and NOAA Earth System Research Laboratory, both in Boulder, Colo. The paper will be published Dec. 8 in Geophysical Research Letters.

[NOTE: We have it here – see link below]

Using computer-generated models as well as observations, the team analyzed causes for climate variations in the recent decades. Special emphasis was given to the reasons for North American coolness in 2008. The research is an exercise in climate attribution, a scientific process for identifying the sources of observed climate and weather patterns. Climate attribution is a vital part of NOAA’s climate services.

“We found that North American coolness resulted from a strong bout of naturally caused cooling in the tropical and northeastern Pacific sea surface temperatures,” said Martin Hoerling, a NOAA meteorologist and co-author. “This illustrates how regional patterns can vary independent of the overall global average. In 2008, global land temperatures were the sixth warmest on record, whereas it was the coldest year in North America since 1996.”

The analysis included historical data and climate model simulations that were conducted in the U.S. and internationally. The science team discerned both natural and human-caused influences for 2008.

“North American temperatures would have been considerably colder in 2008 had there been no human-induced warming influence present,” Perlwitz said.

The scientists conclude that the North American temperatures are likely to resume increasing again, and do not see the recent coolness as an emerging downward trend.

“Our work shows the importance of the role of natural climate variability in temporarily masking or enhancing human-induced climate change. Through diagnosis, we ensure that natural changes, when occurring, are not misunderstood to mean that climate change is either not happening or is happening more intensely than the expected human influence,” said Arun Kumar, a NOAA meteorologist and co-author.

Authors of A strong bout of natural cooling in 2008 are Judith Perlwitz, Cooperative Institute for Research in Environmental Sciences, Boulder, Colo., and NOAA Earth System Research Laboratory, Boulder, Colo.; Martin Hoerling, NOAA Earth System Research Laboratory, Boulder, Colo.; Jon Eischeid and Taiyi Xu, both of the Cooperative Institute for Research in Environmental Sciences, Boulder, Colo., and NOAA Earth System Research Laboratory, Boulder, Colo.; and Arun Kumar, NOAA Climate Prediction Center, Camp Springs, Md.

The work was funded by the NOAA Climate Program Office.

NOAA understands and predicts changes in the Earth’s environment, from the depths of the ocean to the surface of the sun, and conserves and manages our coastal and marine resources.

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Link to GRL Paper is here

(Thanks to Leif Svalgaard)

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photon without a Higgs
December 7, 2009 10:14 pm

Cooler North American temperatures in 2008 resulted from a strong natural effect, and the overall warming trend that has been observed since 1970 is likely to resume, according to university and NOAA scientists.
I’ve seen predictions from them be wrong before.
The sun, as noted by a post here at WUWT, is getting quieter.
They shouldn’t look for results that come from increased energy from the sun to happen when there is no increase in energy from the sun.

Pieter F
December 7, 2009 10:16 pm

Cool sea surface temperature? In the previous thread, Congressman Ed Markey said (in the CNN video posted by Ron de Haan), “We are reporting this year the warmest ocean temperature in history. The last nine years have been amongst the top ten warmest in the history of the planet.”
His co-author in the Waxman-Markey climate bill said earlier this year that “evaporating” Arctic sea ice would cause a “catastrophic rise in sea level.”
Is it necessary to point out that by all reasonable measures the Medieval Warm Period, most of the Late Holocene prior to about 500 AD, the Eemian Interglacial, and most of the entire Eocene were warmer — much warmer — than present? Does it take a 5th grader to explain to Congress that melting ice on water does not increase the level of the water?
These two members of Congress are the best we can do? To think people listen to and believe these clowns. Perhaps we are doomed.

Leon Brozyna
December 7, 2009 10:17 pm

“The recent coolness was caused by transitory natural factors that temporarily masked the human-caused signal.”
I expect this line will get quite a workout over the coming decades as the climate cools. Then, when it starts to evoke snickers, it will switch to how natural factors are having a greater expected effect than expected and is still masking climate change, giving us a few more years to save the planet. And when more snickers ensue, the cause of the cooling will be pollution itself.
By then, China will be an industrial superpower and the self-righteous will hold up examples of American sacrifice, having self-destructed its economic base and call on China to join in the crusade to save the planet. And the people in China will look at the West in amazement and wonder why they should give up the pleasures of warmth and prosperity.

December 7, 2009 10:19 pm

“North American temperatures would have been considerably colder in 2008 had there been no human-induced warming influence present,” Perlwitz said.
Of course . . .

rbateman
December 7, 2009 10:21 pm

My non-computerized observations of flora, fauna and human behavior all indicate that 2009 follows 2008 as ever colder.
It wasn’t likely for the Sun to have spent 2 years sinking ever deeper, either, but it happened. And most predictions missed it.
Global Warming is over.
We have returned to the 70’s cooling period level in short order.
Lay the computer models down, and get back to the business of restoring the historical data that has been computationally corrupted.
The Models have no more value in predictability than did the highwire-act market-bubble models. When they fail, they fall flat on thier face.

savethesharks
December 7, 2009 10:22 pm

“NOAA understands and predicts changes in the Earth’s environment, from the depths of the ocean to the surface of the sun, and conserves and manages our coastal and marine resources.”
Uh huh. Whatever. Methinks NOAA protesteth too much.
“Through diagnosis, we ensure that natural changes, when occurring, are not misunderstood to mean that climate change is either not happening or is happening more intensely than the expected human influence,” said Arun Kumar, a NOAA meteorologist and co-author.”
And my hard-earned tax dollars are paying YOUR salary to deliver this bunk??
“To mean that climate change is either not happening?”
Huh? Wha?? Whoever contested that climate is not changing?????? Nobody in their right mind.
Climate changes. That’s what it does.
THIS type of sophistry folks….funded by the taxpayer…its days are numbered.
Attention bureaucracientists and the the politicians that support them:
Your ill-gotten reign…is about to end.
Chris
Norfolk, VA, USA

December 7, 2009 10:22 pm

Is there, really, any unambiguous factual data proving that there is a “human-caused signal” and allowing us to measure its extent exactly?
If not, why there is almost nobody in the scientific community who would protest ideologically driven statements of this kind?
These people, Perlwitz and Kumar, are truly shameless. What they are doing is worse than prostitution.

Richard deSousa
December 7, 2009 10:25 pm

Why is there no mention of the PDO?? Is there a bias in NASA’s research?

DJ Meredith
December 7, 2009 10:26 pm

“Our work shows that there can be cold periods, but that does not mean the end of global warming…”
Yeah, and my our work shows that there can be warm periods, but that does not mean the end of global cooling.

Terry Jackson
December 7, 2009 10:26 pm

You may want to look at this site for some historical comparisons. They do a pretty good job of introducing progressively longer time periods. http://www.foresight.org/nanodot/?p=3553 The site is about nanotechnology but takes up climate in this post.

paullm
December 7, 2009 10:26 pm

What we have here are all kinds of maybes that do not amount to any kind of support for the destruction of the worlds economies in order to address the age old problem of what I see as the real goal of the AGWers – the conquering of WEATHER CHANGE. However, rather than being laughed off the stage the AGWers call it Climate Change. Using AGW, which has morphed into WEATHER CHANGE (Climate Change), as the very short timeline basis for economic turmoil is an unforgivable “crime against humanity”.
(I have the UNFCCC show on (CSPAN) as I write this. Gawd! That second girl soloist in the Danish Girls Choir was so bad I had to turn the sound off until the piece was over. The Opening – WHAT A REAL PAGEANT OF CRAP! The movie, the self adulation of the participants, the drapings, the lies. )
“Cooler North American temperatures in 2008 resulted from a strong natural effect, and the overall warming trend that has been observed since 1970 is likely to resume, according to university and NOAA scientists.”
“Our work shows that there can be cold periods, but that does not mean the end of global warming.”
“North American temperatures would have been considerably colder in 2008 had there been no human-induced warming influence present,” Perlwitz said.
– OK, how about admitting the NOAA couldn’t see 2008 coming. Where are some specific predictions. How about proof that the models have worked,, instead of just continually adjusting them to predict the past?
(Pachauri is speaking of the ‘sinking of the Maldives’. What a piece of work. I can’t take him any more……….

Mapou
December 7, 2009 10:28 pm

“We found that North American coolness resulted from a strong bout of naturally caused cooling in the tropical and northeastern Pacific sea surface temperatures,” said Martin Hoerling, a NOAA meteorologist and co-author. “This illustrates how regional patterns can vary independent of the overall global average. In 2008, global land temperatures were the sixth warmest on record, whereas it was the coldest year in North America since 1996.”
After reading this, I still have no idea what caused the cooling. I have two questions. First, what would be considered an *unnaturally* caused cooling of North America? Second, why did the tropical and northeastern Pacific sea surface temperatures decrease in 2008? Enquiring minds want to know.

Andrew
December 7, 2009 10:29 pm

CO2 CAUSES global warming, EXECPT….., or UNLESS…., or IF…. or, or , or, give me a minute, I’m thinking…….
The science must stand on its own.
In science the burden of proof is on the theory.
The theory must provide the proof.
If the theory makes a prediction, which it must to not simply be a hypothesis, and the prediction is wrong then the theory is discarded.
That is part of the scientific method.
The AGW theory predicts that CO2 causes global warming.
CO2 is higher now then it was in 1998.
Average global temperature has been declining since 1998
The prediction made by the theory is wrong therefore the AGW theory must be discarded.
QED.
It is called the scientific method. It only takes one wrong result to discard a theory.
‘No amount of experimentation can ever prove me right; a single experiment can prove me wrong.’ Albert Einstein
Please see also:
scienceandpublicpolicy.org/originals/climategate.html
For a satirical look at the climategate computer programming:
Anthropogenic Global Warming Virus Alert.
http://www.thespoof.com/news/spoof.cfm?headline=s5i64103

Nigel S
December 7, 2009 10:29 pm

Well of course the cooling was natural but so was the heating.

James F. Evans
December 7, 2009 10:29 pm

The new doublespeak: When it gets cooler, that’s part of ‘warmer’.

Mapou
December 7, 2009 10:31 pm

Two more questions. Why the repeated reference to global warming and why is it relevant to the findings of the study?

December 7, 2009 10:33 pm

Warm temperatures = Anthropogenic factors. Cool temperatures = Natural factors…
Of course! Silly me! How could I have been so stupid?
/sarcasm
Cheers

Steve S.
December 7, 2009 10:35 pm

Yeah sure and we’re supposed to imagine NOAA has some credibility when their new head, Lubchenco, claims
“CO2 emissions have turned parts of the ocean so acidic that it’s corrosive”.
And created “Osteoporosis of the sea.”

Or
“climate models are robust enough to predict wind patterns 100 years from now”.
Or who after spending 5 years and a $9 million NAS grant failing to find an AGW link to ocean dead zones, simply made up one.
We live preposterous times managed by preposterous people.

December 7, 2009 10:38 pm

So, the natural variablity of Sea Surface Temps cause the recent years of cooling and the exceptionally cool year of 2008 specifically.
The paper doesn’t really get into what causes the variablity of Sea Surface Temps, but does frequently admit a 10 year cooling trend.
They plugged in the SST variablity to the models and the cooling is explained with any doubt an AGW explained.
I wonder how many years of cooling it will take before weather becomes climate?
As a computer simulator this type of ‘proof’ drives me nuts. In the ‘old days’ the math folks came up with formulas to predict the orbit of mars while maintaining that the earth was the center of the universe. Just plug in the right fix to the computer models and what should be common sense proof that the models are not accounting for solar effects or why we warmed after the last little ice age, is explained away.
This is so much like religion driving science. Disenting scientists are in ‘house arrest’.

David
December 7, 2009 10:38 pm

“the expected human influence” Expected?
That said, how much of recent warming is due to natural causes? Why wait until there is cooling to try and attribute natural variations? What is the expected cooling’s actual value?

pat
December 7, 2009 10:38 pm

This meme that global warming can cause cooling is a bit tiresome. it violates the first law of thermodynamics and it is about time the grown ups stopped the children from playing doctor.

Doug in Seattle
December 7, 2009 10:39 pm

And if it persists for 20 more years? Let say . . . in conjunction the negative PDO? What will they call that?

Paul Vaughan
December 7, 2009 10:42 pm

So the soundbite is:
Cooling can happen for natural reasons but warming is anthropogenic. (Is that too many syllables to be realistic?)

Jan Lindström
December 7, 2009 10:42 pm

Guess how the “overwhelmed”, underlying, antropogenic warming trend was “showed” in the paper? I am not sure this is science anymore..

F. Ross
December 7, 2009 10:46 pm

The way I read it, just more toeing the old PC line.