Cites Natural Causes
Tom Spears, Canwest News Service
It’s wrong to blame our warming climate on human pollution alone, says a major analysis by U. S. climate scientists who say North America’s warming and drying trend also has important natural causes.
Natural shifts in ocean currents have caused much of the warming in recent decades, and almost all of the droughts, says the U. S. National Oceanic and Atmospheric Administration (NOAA).
Most climate researchers today deal exclusively with man-made “greenhouse” gases, and often dismiss suggestions of naturally caused warming as unscientific.
Yet NOAA says Western Canada has warmed by two degrees and Eastern Canada hasn’t warmed at all because flows of air from naturally shifting Pacific currents have affected the West most.
The lengthy re-analysis of climate data doesn’t dispute that greenhouse gases from fossil fuels cause a warmer climate. But it raises questions about the details: How much warming? How many causes? And why isn’t it the same every-where?
It also stresses that we don’t understand climate as well as we like to think, because scientists only have good data from about 1948 onward.
“Most of the warming [worldwide] is the consequence of human influences,” said Martin Hoerling, a NOAA climate scientist. But he said the question remains, “What does that mean for my backyard?”
Policy-makers need to know whether natural changes or pollution is causing local conditions such as the current drought from California across to Texas, the report notes.
“All regions are not participating [in warming] at the same rate as the global temperature is changing,” Mr. Hoerling said. Some in the West are warming rapidly, and some not at all (the southeastern United States and Atlantic Canada).
Oceans carry vast amounts of heat, releasing heat and moisture into air, which then travels inland. The re-analysis focused on this fact.
Some of the changes in North America’s warming trend of the past half-century have been due to shifting ocean currents, the NOAA team found. It estimates the “natural” change is substantial and could be close to half of all warming in North America (though it is still less than the amount caused by greenhouse gases.)
The study found:
– The 56-year trend of annual surface temperature showed a rise of 0.9C, plus or minus one-tenth of a degree.
– The greatest warming — up two degrees — has taken place across Alberta, Saskatchewan, Yukon and Alaska. Quebec and Atlantic Canada stayed cool.
That East-West difference “is not what we would expect from the effect of greenhouse gases alone,” Mr. Hoerling said. Greenhouses gases should have influenced both. However, NOAA believes Western Canada is receiving more warm air due to shifting patterns of the Pacific Ocean currents.
– Variations within North America “are very likely influenced by variations in global sea surface temperatures through the effects of the latter on atmospheric circulation, especially during winter.” The term “very likely” is defined as a chance of 90% or more.
– It’s “unlikely” that patterns of drought have changed due to global warming caused by human pollution. Rather, natural shifts in ocean currents are probably to blame. For instance, the current drought in Texas and the southwest are due to La Nina, a Pacific Ocean current that starts and stops periodically (such as El Nino), and cuts off the movement of moist air inland. Warmer temperatures from greenhouse gases, however, would worsen the basic drought.
– Seven of the warmest 10 years since 1951 occurred in the decade from 1997 to 2006. The data in the study cover only to the end of 2007.
The study, Reanalysis of Historical Climate Data for Key Atmospheric Features, was completed in December but hasn’t been widely publicized.
(Read the report here, PDF 8 MB)
Meanwhile, a study published in the research journal Science last week raises further questions about our under-standing of global warming. It disputes the theory that global warming is causing more major hurricanes.
NOAA and the University of Wisconsin at Madison blame, instead, a reduction in the number of volcanic eruptions and dust storms near the equator. When there’s less airborne dust and ash, more sunshine reaches the planet’s surface, which warms the tropical oceans and spawns strong hurricanes.
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Out of topic but interesting: Medieval Warming Period was warmer than the last recent warming and it was global. Now the debate centers on what caused the MWP. From Science Magazine this week:
http://www.sciencemag.org/cgi/content/full/324/5923/78
Pete,
Please explain to me (since you seem to know so much) why the planet has been cooling for 10 years when all climate computer models predicted a temperature increase? Preferably, please use NASA satellite data as the basis for your explanation. Also, it would be helpful if you could explain the rationale behind the aerosol forcings assumed in the climate models since they don’t appear to match reality. Finally, please prepare a summary of the programming logic used in the climate models that determine climate sensitivity to CO2. Links to the pertinent lines of Fortran code would be helpful. Thanks!
Pete Simmons said
“Most of you are probably too young to even know what the climate was like thirty years ago, forty years even, you get all your ‘knowledge’ from websites, and believe it. If you did have experience of the climate in the past, you would know it’s changed.”
I know of no one at all on this web site that denies the climate is changing. Equally perhaps they know -as you don’t appear to- that climate change is something that occurs on a permanent basis, and instead of glancing back only thirty or forty years, we look back scores, hundreds and thousands of years.
Then you would know that plants could live much farther north than now, that trees grew at higher altitude than now, that people farmed at higher places than they do today, that the Arctic ice has melted every 60 years or so and there are vestiges of an ancient civilisation in the High arctic regions.
Has the MWP, the Roman warm period, the Holocene optimums completely passed you by? Are you unaware of the considerable warming in the 1920’s and 30’s which triggered exactly the same headlines as we see now? Are you unaware of the warming that Thomas Jefferson wrote about? Have you never heard of the Vikings and their habitation of Greenland?
Before you start making unsubstantiated comments I suggest you learn more of the subject and be a bit more aware of the earths continually changing climate which strectches back much further than thirty or forty years and were marked by storms and droughts much greater than we see today.
Please think before you post and look at some of the numerous threads here that may open your mind a little.
Tonyb
I posted this yesterday off topic on a different thread. Thought I would put it on topic.
Using the new article, I’ve done a “back of the envelope” estimate that the climate sensitivity to a doubling of CO2 is ~1.65C.
Here’s the relevant bits from the story:
—snip—
Some of the changes in North America’s warming trend of the past half-century have been due to shifting ocean currents, the NOAA team found. It estimates the “natural” change is substantial and could be close to half of all warming in North America (though it is still less than the amount caused by greenhouse gases.)
The study found:
– The 56-year trend of annual surface temperature showed a rise of 0.9C, plus or minus one-tenth of a degree.
…
– Seven of the warmest 10 years since 1951 occurred in the decade from 1997 to 2006. The data in the study cover only to the end of 2007.
—snip—
So a bit more than half of the 0.9C increase is due to GW. I’ll use 0.9C * 55% = ~0.5
I’ll also use the Mauna Loa CO2 measurements for the study start and end dates:
1951: 311 ppm
2007: 383 ppm
If I understand it correctly, the change in temp can be calculated as:
tempchange = forcefactor * ln(CO2[end]/CO2[start])
so:
forcefactor = tempchange / ln(CO2[end]/CO2[start])
Plugging in the above values we get:
forcefactor = 0.5 / ln(383/311)
forcefactor = 2.4
And sensitivity to doubling of CO2 as:
sensitivity = forcefactor * ln(2)
sensitivity = 1.65C
This is significantly less than the 3.0C estimated by the model ensemble used by the IPCC.
Also interesting, this is consistent with Bill Illis’s analysis from a while back:
http://wattsupwiththat.com/2008/11/25/adjusting-temperatures-for-the-enso-and-the-amo/
A few points:
– I haven’t read the actual study. It’s based solely off the news story.
– I couldn’t determine if the reported trend was for North America only or global.
– The article did not mention which temperature record was used, but being a NOAA study, I can guess.
All the usual caveats and discussion points apply.
AJ
Pete Simmons (05:15:54) : Awh. . ., come on Pete, lighten up.
We are neither young nor old, neither farmers nor apartment dwellers, nor any other category you would like to put us in. I guess we could all be from Missouri, “The Show Me State.” This “conotates a certain self-deprecating stubbornness and devotion to simple common sense.”
I think most here acknowledge the Earth’s climates change but not that human activities have much to do with it. Apparently you believe the opposite.
So, explain to me why Earth had an ice age 20,000 years ago and this is not so today? I can show you the ice age existed. You cannot show me how humans caused it to go away.
Chill! Have a drink! Cheer up!
I have read the Executive Summary’s key findings of this report and have some thoughts on them.
• Seven of the warmest ten years for annual
surface temperatures from 1951 to 2006
have occurred between 1997 and 2006.
Just common sense would tell you this was true since it was the only period during the study when both AMO and PDO were warming simultaneously
• Virtually all of the warming since 1951 has
occurred after 1970.
Again this is the only period when PDO was warming 1976 -2007 and AMO was warming 1994-2009
• More than half of this warming is likely
the result of human-caused greenhouse gas
forcing of climate change.
What does LIKELY mean. To me this implies doubt?
• Changes in ocean temperatures likely explain
a substantial fraction of the human caused
warming of North America.
This is very confusing. How can changes in ocean temperatures explain a substantial part of human caused warming? They are two different causes entirely. Are they trying to say that ocean temperatures account for much more of the PREVIOUSLY AND ERRONEOUSLY attributed human caused warming?
What does substantial fraction mean [ if more than half of warming is human caused and a substantial part of this is ocean caused , what is left that is human caused. VERY LITTLE
Pete Simmons (05:15:54),
I’m sure you will get lots of responses. However, You clearly don’t understand the position of most AGW skeptics. Although many skeptics have their own pet theories I’d say the vast majority feel that no one understands climate well enough to say anything conclusive about the causes and effects.
That doesn’t mean skeptics feel that man is not PART of the equation, just that there’s no way to determine how much impact should be atrributed to man. Until this can be understood we should not be running off half cocked trying to fix something we have no idea is broken. The latest mitigation experiment (dumping iron into the ocean) covered here recently is ample evidence of that.
Please stay around and try and understand the facts and the data. I think you will be surprised if you keep and open mind.
I also find it humorous that you assert the skeptics are all young. Another recent attempt to generalize skeptics claimed we were all old. The truth is if you want to generalize skeptics then what you will find is they are mostly intelligence logical people that like to understand the world around them.
Finally, maybe you should take some time to get to know and understand farmers. You might be surprised as to what you can learn. However, if you truly hate farmers then I’d suggest you boycott all their products. That would demonstrate you really believe what you have stated.
Caleb (06:10:48) : & Richard Heg,
Note that while the article seemed to imply an attempt “. . . to once again shrink the MWP”, as you say, it emphatically drew simutaneous timing links between most of the major climate makers around the world.
As for the MWP, it is being continually re-certified, here:
http://co2science.org/ . . . on a weekly basis
Medieval Warm Period Record of the Week
Was there a Medieval Warm Period? YES, according to data published
by 687 individual scientists from 402 separate research institutions in
40 different countries … and counting!
Keeping with my previous post, this fits the “show me” category.
Bruce Foutch (06:17:30) : Thanks for the link to missing pages.
Pete Simmons (05:15:54) :
You need to calm down.
We know climate changes – always has, always will. Man’s effect on climate is pretty much nil, though, and that is what the debate is all about.
And, FYI, ranting, name-calling, or otherwise attempting to belittle or denigrate is not an effective tactic to use, and in fact not only puts you in a bad light, but diminishes whatever argument you are trying to make. The science disputing manmade warming is sound, and readily available. The “consensus” argument is not a sound scientific one, and whatever “consensus” there was is actually falling apart.
John F. Hultquist (08:16:45) :
Caleb (06:10:48) : & Richard Heg,
As for the MWP, it is being continually re-certified, here:
http://co2science.org/ . . . on a weekly basis
Medieval Warm Period Record of the Week
And here this week:
http://www.sciencemag.org/cgi/content/full/324/5923/78
A piece from the article:
“We present here a 947-year-long multidecadal North Atlantic Oscillation (NAO) reconstruction and find a persistent positive NAO during the MCA. Supplementary reconstructions based on climate model results and proxy data indicate a clear shift to weaker NAO conditions into the Little Ice Age (LIA).
Here’s a nugget I found on the PMEL website. Check out this paper on modeling arctic climate using AOGCMs:
“Intrinsic versus forced variation in coupled climate model simulations over the Arctic during the Twentieth Century, ” Wang et al., J. Climate, 20(6), 1093–1107 (2007).
http://www.pmel.noaa.gov/pubs/outstand/wang2804/abstract.shtml
The paper compared “predictions” from over 20 models with historical data. Here’s the money quote:
“We consider that the eight models [GISS-AOM, GISSEH, GISS-ER, IPSL-CM4, MIROC3.2(hires), MIROC3.2(medres), MRI-CGCM2.3.2, and FGOALSg1.0] that did not pass both criteria (magnitude in 20C3M simulation and control runs variance) do not have enough intrinsic decadal variability to produce a reasonable magnitude for arctic warm anomalies.”
In other words these 8 models couldn’t even ** hindcast ** the arctic climate very accurately! And what do you know – all the GISS codes failed. Gavin – what say you??
The biggest drought I know of in N. America occured in the last half of the 1500’s. There was another one in the 8th century (735-765).
http://adsabs.harvard.edu/abs/2002AGUFMPP71C..04S
There was no AGW cause for either one.
Yes, it is wrong to blame everything on man, not that man is innocent.
The public is really getting sick & tired of the constant spew of AGW scare.
It reads like sour grapes and a slick con job.
Mr Lynn (05:42:17) :
Not really OT: Despite a little hedging, the drumbeat continues:
“Small islands urge deep CO2 cuts, fear rising seas”
http://www.reuters.com/article/environmentNews/idUSTRE5305AT20090402
Have they closed their international airports yet?
From Spaceweather.com:
NEW: Spotless Days
Current Stretch: 26 days
2009 total: 80 days (87%)
Since 2004: 591 days
Typical Solar Min: 485 days
Is that “Typical Solar Min” number right? How do you define the boudaries for the minimum and maximum anyway?
It is not about warming or cooling, it is just a psychological pandemic infection affecting the northern hemisphere.
and…the cure I have told it already, but I need to repeat it, it is CASTOR OIL; the old and faithful castor oil. It will empty gwrs’ guts and, in so doing, it will liberate them of all those harmful toxins circulating through their already small brains.
The study found:
– The 56-year trend of annual surface temperature showed a rise of 0.9C, plus or minus one-tenth of a degree.
Let’s see: 56 X .9C = 50.4C ??
Probably should read either: The 56-year period showed an increase in temp of 0.9C, or, the trend over the 56-year period was 0.016C/year. C’mon Mr. Spears, get it right.
Pete Simmons (05:15:54),
You the Pete Simmons who grew up in Arnold, MD ?
“In other words these 8 models couldn’t even ** hindcast ** the arctic climate very accurately! And what do you know – all the GISS codes failed. Gavin – what say you??”
Any programmer who has looked at the GISS code knows full well the code has many errors. That much code that has been modified several times and lacks proper documentation will have programming errors. PERIOD! If a first year compsci student wrote this code they would get a big red F.
What’s interesting about this situation is the algorithms could actually be fine and simply programmed wrong.
Aron (00:25:45) :
What is this crazy black line?
http://www.newscientist.com/data/images/ns/cms/dn11648/dn11648-2_726.jpg
This chart is credited to Robert Wilson of Edinburgh University. A quick look at his homepage offers this:
“I am currently funded through the European Union on a project entitled, “Millennium – European Climate of the last Millennium. The Millennium project is a multidisciplinary consortium of more than 40 European universities and research Institutes, with the aim of answering a single question:
Does the magnitude and rate of 20th Century climate change exceed the natural variability of European climate over the last millennium?”
The Millenium project appears to apply global-climate against Euro-climate. But it does include the phrase “natural variability.” Something we can expect to hear more of as AGW is phased downward.
Now “they” are admitting the existence of the Medieval Warm Period. Explained by
the North Atlantic Oscillation. And Mann is cetting close to admitting a solar driver:
” It’s wrong to blame our warming climate on human pollution alone…’
So, if a Mt Redoubt spews x tons of SO2 into the atmosphere, that is natural, but if coal-burning plants spew the same molecule, that is pollution?
Maybe the whole biosphere is pollution.
It means that’s the reason they’ve chosen, therefore it’s “likely”.
It’s more likely that we’re still shooting in the dark, and one reason is as likely as any other at this point.
Obviously assuming that all natural forces are cooling the planet is a bad assumption or presumption, since the Earth has been warmer than now many many times in the past, even the recent past. So your analogy falls apart right there.
Having skimmed through the entire report:
PDO and AMO are treated very superficially as if they are not relevant. No plots of PDO or AMO together with temperature anomalies to show relationships. This appears to be strange as they clearly say that the STRENGTH OF LINK BETWEEN ATMOSPHERE AND OCEAN IS STRONG for both the AMO and PDO.
The shift of climate when PDO went negative in 1976 is strangely explained as
“From an oceanographic perspective, changes in ocean heat content and SST’s that happened suddenly over the Pacific basin north of 30 degrees N were caused by atmospheric circulation anomalies.”
Warm periods are highlighted, cool ones are not
El Nino’s are talked about; la Nina’s are hardly mentioned
No evidence to support why for a North American study, they would say “most of the warming [worldwide] is the consequences of human influence. They suddenly jump to worldwide from a local study and just assume that the same applies.
When they use the term LIKELY it means more than 66 % PROBABILTY
This report is clearly prepared to support the AWG point of view primarly
The report is about weather and climate but no professional or working meteorologist is part of the team.