Global warming underestimated?

By: Dr. Jeff Masters , 3:00 PM GMT on February 10, 2006

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Are the official estimates of a 1.4° to 5.8°C (2.5° to 10.4°F) increase in global mean surface temperatures by the year 2100 significantly in error? That was the conclusion of MIT professor Dr. Peter H. Stone, in a lecture I attended last week at the annual meeting of the American Meteorological Society. Dr. Stone's results were also published January 13, 2006 in Geophysical Research Letters. The "official word" in the science of climate change comes from the United Nations-sponsored Intergovernmental Panel on Climate Change (IPCC), a collaborative effort between over 2,000 scientists from over 100 countries, including many of the top climate researchers in the U.S. The IPCC publishes an extensive assessment of the state of the science every six years. The most recent report, issued in 2001, predicted the 1.4° to 5.8°C increase. If Dr. Stone is right, the next IPCC assessment, due out in 2007, will have to revise that estimate upwards.

Dr. Stone started his talk by posting this quote from the Executive Summary of the 2001 IPCC model evaluation chapter: "Confidence in the ability of models to project future climates is increased by the ability of several models to reproduce the warming trend in 20th century surface air temperature when driven by radiative forcing due to increasing greenhouse gases and sulphate aerosols." (The term "forcing" in climate research refers to any process, natural or human-caused, that "forces" the climate to respond in a significant way.) The IPCC report supported their statement by comparing climate simulations of the observed 20th century climate that used just natural processes ("forcings" such as volcanic eruptions and natural changes in the sun's brightness) with simulations done including human-caused "forcings" (greenhouse-effect gases added since pre-industrial times, plus aerosol particle pollution). Dr. Stone presented Figure 4 (below), a modified version of a figure from the 2001 IPCC report. The figure shows a typical 20th century climate simulation by one of the major climate models used for the IPCC assessment--the UK Hadley Center model. The results look good. The model is able to reproduce the observed climate of the 20th century. In addition, the simulation shows that one cannot explain the observed 20th century global warming of 0.6°C without including human-caused (anthropogenic) climate forcings.



Dr. Stone argued that the IPCC's confidence in the ability of models such as the UK Hadley Center Model to predict future climate was invalid, and that the good agreement between the observed climate and model prediction seen in the figure above could have been coincidence. He outlined several ways that compensating errors in two or more areas of model uncertainty could have produced a climate simulation that matched the observed 20th century record.

Major uncertainties in climate change computer models include:

1) Climate Sensitivity (how much global surface temperature changes when CO2 is doubled)
2) Rate at which the oceans take up heat
3) Strength of forcing by aerosol particles
4) Natural variability

For example, if a model has a Climate Sensitivity that is too great (the model predicts too much warming for a given increase in CO2), and improperly assumes too much cooling will occur due to pollution from aerosol particles, the two errors will cancel each other out and lead to a realistic-looking simulation. The Climate Sensitivities of the 11 key models used to generate the 2001 IPCC results varied by about a factor of 2.5, from 1.5°C to 4.5°C. Similarly, the amount of heat taken up by oceans varied by about a factor of 2.5 in the models. Additional uncertainties exist in the models' treatment of aerosols and natural variability.

Rather than dismiss the climate models as being too filled with uncertainty to be useful for performing climate simulations, Dr. Stone maintained that one can do an intelligent uncertainty analysis by varying two of the major uncertainties in a model simultaneously, and study the resulting model predictions. He described his group's research to evaluate the uncertainties in 11 of the key models used to formulate the 2001 IPCC climate report. The study was done using data from the Coupled Model Intercomparison Project (CMIP), an international research program begun in 1995. The talk then became quite technical, with several plots showing Probability Distribution Functions on parameter-space diagrams. It was at this point I bemusedly watched the audience member next to me who hadn't had enough cappuccino that morning repeat the classic pecking bird "doze-droop-jerk-I'm awake!" pattern. Meteorology talks aren't always filled with captivating displays of 3-D Category 5 hurricanes! There's a lot of hard science needed to understand the concepts.

Finally, Dr. Stone finished his uncertainty analysis, and he presented some rather startling conclusions:

1) Models have been over-estimating the rate of mixing of heat into the deep ocean.

2) This implies that their projections of surface warming for the 21st century are too low.

The guy next to me jerked fully awake now, and the audience got noticeably more attentive. "And this worries me," Dr, Stone continued. "It worries me enough that we've made many extensive tests of our methodology that try to make sure that there are no flaws. I would be delighted if anybody here could come up with a test that we might look at to see if we've done anything wrong." The audience, filled with several hundred people, including many of the world's foremost climate experts, was silent. No one could come up with a reason to dispute Dr. Stone's gloomy conclusion.

So how much in error are the climate models? Dr. Stone didn't give a number in his talk, and when I asked him about this later he said he had only a rough preliminary idea of what this error might be. His research team is currently analyzing their results to see how much additional warming we can expect. When they publish some specific error estimates, I'll be sure to post a follow-up blog on the subject.

Professor Stone's talk can be heard on-line for free. To do so, you must install the free WebEx player for IE or Netscape. Note: this will not work for other browsers, such as Firefox! The talk is about 40 minutes long, and includes figures. Alternatively, you can read the paper on the subject that he co-authored along with C.E. Forest and A.P. Sokolov of MIT's Joint Program on the Science and Policy of Global Change:

Forest, C.E., P.H. Stone, and A.P. Sokolov, "Estimated PDFs of climate system properties including natural and anthropogenic forcings", Geophysical Research Letters, 33, L01705, doi:10.1029/2005GL023977, 2006.

A free abstract of the paper is available from the agu.org website. A full version costs $9 for non-subscribers.

A note on my global warming blogs
In an issue as complex, contentious, and important as global warming, it is impossible for anyone to present an unbiased and fair treatment of the subject. My bias will be towards presenting new scientific findings published in peer-reviewed journals, as well as calling attention to the political aspects of the debate when it appears that one side or the other is attempting to twist or hide the truth. While thus far I have only focused on the NASA/Dr. James Hansen affair, I also have criticism of those claim that Hurricane Katrina was significantly enhanced by global warming. Although it is possible that global warming did contribute significantly to Katrina's intensity, the current best hurricane science supports only a 1-2 mph enhancement in Katrina's winds by global warming. I have a blog on this topic I plan to post next week, highlighting recent questionable statements by the editor of Science magazine on the matter.

For those of you following the NASA/Dr. James Hansen affair, see this morning's New York Times article, where George C. Deutsch, the young NASA press aide who resigned on Tuesday amid claims that he had tried to keep Dr. James Hansen from speaking publicly about global warming, defends himself publicly.

A note on media bias on the global warming issue
I'm of the opinion that articles in the New York Times on global warming tend to be biased in favor of dramatizing the problem and calling for action. Articles in the Wall Street Journal, Washington Times, and Newsweek magazine generally have the opposite bias. Time magazine seems pretty neutral, and CNN.com may have a pro-action bias. I'm not sure about the USA Today, Washington Post, or other sources. One of my favorite sources of global warming info (but a little too technical for many readers) is from realclimate.org, which is maintained by some of the top climate scientists in the field. They have serious disagreements with the Wall Street Journal.

Jeff Masters

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127. Fshhead
9:57 PM GMT on February 10, 2006
Gotta go to work BUT, I will definitly come back after to see how the war is going LMAO!!!!!!!!!
Member Since: November 19, 2005 Posts: 9 Comments: 9960
126. Fshhead
9:56 PM GMT on February 10, 2006
Chaser I accept MY part on MY blog!!!!
BTW I hope evrything is well with U.
Member Since: November 19, 2005 Posts: 9 Comments: 9960
124. hurricanechaser
9:54 PM GMT on February 10, 2006
Fsshead,

To clarify, the views expressed in your blog of a political tone spilled over into this blog. I am not tryiong to blame you for it was just timing I suppose. However, we ALL have our own part in continuing the political discussions including DR. Masters.

I accept my part in it, can anyone else do the same?

Stormtop,

you were the one who asked for clarifdication on the Bibles view of Homosexuality from last nights blog wgich started that discussion from Inyo and others. I make no apologies for ANYTHING I said regarding my religious views for I not once attacked another in expressing them. I hate the sin of homosexuality but love the person who committs the sin. Just as we all sin. I was sharing the Bibles view from Scripture as you know.:)

Thanks,
Tony


123. Fshhead
9:53 PM GMT on February 10, 2006
Posted By: smadsen8486 at 3:11 PM GMT on February 10, 2006.
pulling up a nice comfy chair on the sidelines, waitin to watch the debate heat up in here!
LMAO!!!!!
Hey Smads....
"Fshhead throws on the flak jacket & dives right in"
Member Since: November 19, 2005 Posts: 9 Comments: 9960
121. Fshhead
9:46 PM GMT on February 10, 2006
In short, I ask that we ALL refrane from personal attaxks and please can we get away from politics which I have been pleading for since Fsshead began his blog that interjected politics into the global warming debate a couple months ago.

Before any of you accept the assumption that I made this political, go back and read the beginnings of Fssheads blog and you will see me continually saying it should not be political. However, when my Christian views are attacked, I will respond as I should.

Hmmmmmmm,
K gotta put my 2 cents in here. I just got done reading all the posts for the last day & 1/2.
Chaser... don't try to blame this heated topic on me..
I was not even hereLOL.
Chaser when I stated those political tones, they were on MY blog. I reiterate MY BLOG. (if memory serves me correct)
Even though we really disagreed I think for the most part it was pretty civil.
I think that bashing Dr. Masters on HIS blog was wrong(glad you apologized).
That being said, this issue IS rather political,viewing the current situation in this country.
Like I said to you before, hopefully the statement in the State Of The Union address holds true for more reasons than just the global warming issue.
Hopefully we will see the BIG experiment unfold before our eyes. Like I said if the data supporting the warming theory is inaccurate & we start to slide back into an ice age.... WE SURE KNOW HOW TO PUT THE GASES BACK!!!!!
Man..... u guys sure get worked up when someone questions your beliefsLOL!!!!!!!!!
Member Since: November 19, 2005 Posts: 9 Comments: 9960
120. FtWaltonBch2Tucson
9:44 PM GMT on February 10, 2006
For those who are interested: We actually got a trace of rain here in Tucson (It's bad when people start cheering for a few raindrops on the ground......). The system was south of us, so we only caught the northern edge. Nogalas got almost .09". Now if we can only get several more of these storms, and not only the edge of them..... Current count: 162 days with less than .25" of rain.
Member Since: January 9, 2006 Posts: 0 Comments: 21
117. haydn
9:29 PM GMT on February 10, 2006
Now I am gone. ....back later
115. sayhuh
9:24 PM GMT on February 10, 2006
TPaul, yeah..I think I agree with you. I looking a the WV imagery, it seems to be tracking a bit further south. Also looking at the GFS, the model looks like the potential for some rapid strengthening?
114. haydn
9:23 PM GMT on February 10, 2006
For those who want to discuss tunnels, I have set up a blog under the subject tunnels. I may or may not join in the discussion. If you decide to post, please read my entry.

Look under Haydn
113. TPaul
9:08 PM GMT on February 10, 2006
Yea, New York and Boston look to be in for it but looks like we are getting some shear from the Northwest that is blocking the moisture from coming as far North and I think shifting the overal track of this storm a little further South. Actually if this storm tracks more South and strengthens we could see a storm like the February 96 storm here. Then we would see our heavy snow on Saturday night Sunday which would take everyone by surprise.
Member Since: May 2, 2002 Posts: 5 Comments: 111
112. haydn
9:05 PM GMT on February 10, 2006
Chaser,

I feel the same you do about some of the above mentioned topics. I have found that being defensive isn't the best thing to do. I have been in your shoes before. It will be hard, but not saying a thing may be the best thing.
110. billsfaninsofla
9:03 PM GMT on February 10, 2006
wow.. hope all this gets out of the system before hurricane season starts..
Member Since: September 5, 2005 Posts: 0 Comments: 5434
109. Cregnebaa
9:02 PM GMT on February 10, 2006
please no more tunnels
Member Since: October 19, 2005 Posts: 6 Comments: 323
108. sayhuh
9:02 PM GMT on February 10, 2006
TPaul, dunno - think this snowstorm will be something else as it moves more northeast...wouldn't want to be in New York this weekend... ;-)
107. hurricanechaser
8:59 PM GMT on February 10, 2006
Just look for the copnsistent perrsonal attacks througout these blogs toward me and you will see WEatherguy03 and his on topic comments.:)

TPaul and others,

can we agree to drop this discussion and let people talk about tunnels and global warming, I'm cool with that myself.:)
106. haydn
8:59 PM GMT on February 10, 2006
I'll be back later. I have to finish the cleanup of an insulation job.

KRWZ would agree with me on this. Can we be nice and pull religion and personal conflicts off the blog?

Fires stop when there is no fuel...eg..our posts.
105. TPaul
8:56 PM GMT on February 10, 2006
Chaser, who is Bob, never mind, I don't want to know. If he is sending you emails just send him emails back. I don't see what all the fuss is about.
Member Since: May 2, 2002 Posts: 5 Comments: 111
104. hurricanechaser
8:55 PM GMT on February 10, 2006
Just for the vrecord everyone, I am all for staying away from politics and religious discusion on here if we can all abide by that. If not, I will ALWAYS respond to any and every religious comment directed to my attention as I should do if I truly care about what I believe and the person asking me the question. You don't haVE TO AGREE OR EVEN LIKE ME BUT YOU SHOULD RESPECT MY EARNEST desire to do what I personally think is right.

103. hurricanechaser
8:51 PM GMT on February 10, 2006
We are off that topic but you are keeping it going Bob.
102. Cregnebaa
8:50 PM GMT on February 10, 2006
Colby what are you trying to work out?

Cyclone I think Caymanite, may be in Cayman which is in the caribbean south of cuba and west of Jamaca.
Member Since: October 19, 2005 Posts: 6 Comments: 323
101. hurricanechaser
8:50 PM GMT on February 10, 2006
Bob,

Please stop the sarcasm and dishonesty. YOu have consistently and unwaveringly attacked me every chance you've had.

Just look at todays posts... please stop with this type of action if you can.

Another recdoncilitory email from my friend, Bob.

"Listen the religous crap has got to stop!! This is not the place for that. I'll even take your diatribes on global warming over that stuff. They have plenty of religous blogs if you need them."

Have I ever said anotyhers beliefs are CRAP? Never, but I can't ge the vsame respect. Yet, I am somehow the bad guy, Whatever, think what you will people. It doesn't have ANY effect on my true intentions and the Truth therein.
100. haydn
8:46 PM GMT on February 10, 2006
Colby, What are you calculating?
99. weatherguy03
8:45 PM GMT on February 10, 2006
And he is still talking!!..LOL..OMG..Chaser give it a rest already..LOL..Noone wants to hear about your religous talk. I can tune into EWTN if I want that!!..LOL..Oh boy!!
Member Since: Posts: Comments:
98. haydn
8:43 PM GMT on February 10, 2006
That was the volume.

If you want a slice, you need the area formula....pi times radius squared
97. weatherguy03
8:41 PM GMT on February 10, 2006
And the beat goes on. I would love to have a conversation here, on the topics at hand. But how could we. He keeps going on and on and on. Well at least I have other blogs to go to discuss some real issues. Its a real shame. Oh well.
Member Since: Posts: Comments:
96. ForecasterColby
8:44 PM GMT on February 10, 2006
Thanks haydn. Earth is close enough to a sphere to make the calculations good enough for this sort of thing.
95. hurricanechaser
8:43 PM GMT on February 10, 2006
Simply put,

Don't attack me personally (feel free to attack my opinions)and we are all cool because I have no desire in doing that to another.
94. hurricanechaser
8:35 PM GMT on February 10, 2006
Tpaul,

How is it a stretch that Dr. Masters wasn't politisizing the debate on Global warming when He keeps repeating characterizations of people who deny whast he posts that are conservative. He consistently bashes the Bush administration and even leaves out the gest of yesterdays article about Mr. Deutsch's denials until a short sentence today.

And, I don't appreciate your judgement saying I am not trying to be reconncilatory when I tried apologizing to both Dr. masters and all about last night and specifically Bob while He continued hios attacks.

Please show me where I am SHOVING my beliefs down anyones throats? That is both inaccurate and very demeaning to my sincere concern and love for others. Who are you to suggest otherwise.

I also take exception with the so called everything has its time and place. I agree, and when someone asks me what I believe about the Bible, it becomes the absolute time ands place to respond with God's Word and you can sit back and worry about othes opinions of you while I'll suffer the attacks for sharing what I said IS MY PERSONAL BELIEFS.

I would never critisize another Christian for sharing the Gospel especially when it was brought to me first.

93. haydn
8:37 PM GMT on February 10, 2006
Colby,

sphere= 4/3 times pi(3.1416) times radius cubed

earth is 7926.41 miles in diameter(average) earth is not a perfect sphere

atmosphere extends to 62 miles. 75% is below 11km or 6.8354 miles.

remember to halve the above diameter or any calculations are messed up
91. ForecasterColby
8:39 PM GMT on February 10, 2006
*rolls eyes*

This is hopeless. I'll come back in a few days and see if this decaying community has come up a bit.
90. cyclonebusted
3:37 PM EST on February 10, 2006
My tunnels would stop the snow
Member Since: Posts: Comments:
89. TPaul
8:34 PM GMT on February 10, 2006
The big snow storm for Central Kentucky looks like it is going to be a bust. I can't imagine that there is anyway for this topic to become heated.
Member Since: May 2, 2002 Posts: 5 Comments: 111
88. TPaul
8:27 PM GMT on February 10, 2006
I was meaning no offense to Sheraqueenofthebeach. I don't mean any offense to you either Hurricanchaser but you saying your are trying to bring reconcillation here is almost as laughable as CBs "tunnels". I am a Christian as well but everyone has there own path and I never agree with shoving my believes down others throats. I also think that your saying that Dr. Masters made this political to start is definitly a stretch of imagination on your part. Now I feel like I have gotten sucked into another discussion I had not planned on, those darn "tunnels".
Member Since: May 2, 2002 Posts: 5 Comments: 111
87. sayhuh
8:33 PM GMT on February 10, 2006
Aside from global warming/other topics..anything of interest weather related going on today?
86. hurricanechaser
8:28 PM GMT on February 10, 2006
Thanks Colby...what is the toipic again? I didn't bring up religion but responed to questins and statements about it directed towards me.
85. sayhuh
8:26 PM GMT on February 10, 2006
Chaser, you may not be the sole reason for the bickering, clearly it takes two to tango, but conversely, you are perpetuating it. Having faith and opinion is fine, and I support that, but there is a time and place. And for off topic rants such as religion..this is neither.
84. hurricanechaser
8:27 PM GMT on February 10, 2006
I have been here as much as most until I got fed up with the personal attacks on others about two weeks ago.
83. ForecasterColby
8:25 PM GMT on February 10, 2006
Chaser, I'll tell you now that if you don't get at least a little back on-topic, you'll either be banned, or the spam reports will remove your posts.
82. hurricanechaser
8:25 PM GMT on February 10, 2006
To I have to remind people that it was Dr. Masters himself who chose to interject politrics into his blogs and I find it hypocritical to set that example and then complain when this weather chat forum gets off topic.

Just my opinion.:)
81. TPaul
8:24 PM GMT on February 10, 2006
I meant no offense to you, hope none was taken. Trying to keep it light as I remember how it was back during Hurricane season. But I have to admit don't seem to see you on here very often. Of course I guess most of us are just lurkers from time to time.
Member Since: May 2, 2002 Posts: 5 Comments: 111
80. hurricanechaser
8:21 PM GMT on February 10, 2006
TPAUL,

It is wrong for you to personally blame me for anything for all this bickering. I have tried to bring reconciliation. But, I can't stop othes from the constant personal attacks.

I make NO APOLOGIES for sharing the Truths of the Bible as I personally see them when I am asked directly about them...please reread previous posts before making inaccurate statements.

Thanks,
Tony


79. Sheraqueenofthebeach
3:20 PM EST on February 10, 2006
Everything has a place TP.
Member Since: Posts: Comments:
77. TPaul
8:15 PM GMT on February 10, 2006
Now see what you have done HurricaneChaser, you have brought out Queen of the Rules.
Member Since: May 2, 2002 Posts: 5 Comments: 111

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Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.

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