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Hansen Has Been Wrong Before
(Part of the How to Talk to a Climate Sceptic guide)
This article has moved to ScienceBlogs
It has also been updated and this page is still here only to preserve the original comment thread. Please visit A Few Things Ill Considered there. You may also like to view Painting With Water, Coby Beck's original fine art photography.Labels: Sceptic Guide
posted by coby @ 4/06/2006 01:43:00 PM
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18 Comments:
At April 06, 2006 6:10 PM,
Anonymous said…
It would be nice to see the originial graph in its original form. The graph everyone shows is from 1998, 10 yers after the fact; and while it includes the observed data, I would like to see it as they orginally saw it in 1988.
Also, I do see it as curious that the Scenario A is represented by the boldest line; to a lay person, this would suggest that the worst case emmissions scenario (A) was actually the most likely scenario (which was actually scenario B).
-sam
At April 06, 2006 7:19 PM,
coby said…
Hi sam,
I agree I'd like to see it, and I checked the link to the 1988 paper and it seems broken. I will try to fix that.
I think line A is solid, not bold, B is broken and C is dotted. It seems to me that 1) this is pretty easy to happen just by chance and 2) it is a pretty weak way to draw attention, especialy on a pretty simple graph.
What if it were intentionally emphasized? Don't we always make warning signs big and bright? Again, I doubt it was.
At April 07, 2006 4:07 AM,
Anonymous said…
Coby, I see in the 1999 paper, Hansen reproduces a graph showing actual vs predicted up till 1999 or so. He also states that with another decade, model accuracy will become more evident (or not). Is there an updated version of this graph, as we're half-way through that decade now?
At April 07, 2006 9:06 AM,
Wag the Dog said…
this would suggest that the worst case emmissions scenario (A) was actually the most likely scenario (which was actually scenario B).
Commenters at RealClimate have discussed that actual testimony and agree that while Dr. Hansen presented a figure with three scenarios, all throughout the rest of his 1988 testimony he described scenario B only.
Is there an updated version of this graph, as we're half-way through that decade now?
Yes. Dr. Hansen included it in a response to Michael Crichton's portrayal of global warming research. It includes observation data up to 2004. The 2005 was a projection as the year was not yet complete. Note that the observation data is not exactly the same as that in the 1998 figure. It seems some very slight corrections were made to later years. This data is actually available from NASA GISS.
Examining Dr. Hansen's updated figure, it seems that he is using the traditional analysis using only meteorological station data for the plot of observations. I've overlayed this (in blue) over the 1998 figure so you can compare for yourself.
At April 07, 2006 4:38 PM,
coby said…
Thanks for your contributions!
At April 07, 2006 4:41 PM,
coby said…
john mann;
Don't forget hindcasting as a great way to test the accuracy of models.
At April 20, 2006 1:22 PM,
Anonymous said…
Umm, doesn't the fact the fact that observations conform to Scenario B indicate that warming over the next century will be fairly modest? And isn't fairly modest (2 deg C or less) warming hard to square with the alarmist rhetoric spouted by Dr. Hansen and others?
At April 20, 2006 1:45 PM,
coby said…
Well, Scenario B in the graphs I am familiar with stops at 2019, so it is not that clear. Such a long term prediction depends too much on human action to be able to predict. It is also very hard to know what effect methane from melting permafrost will do and if we will encounter significant releases of methane clathrates in ocean sediment.
All that aside, history does not support the notion that 2oC more warming (for a change of 3oC since pre industrial) in two centuries is modest, nor does time stop in 2100AD.
3oC warmer oceans will guarantee heat death of virtually all coral reef in the ocean and will commit us to several metres of sea level rise, though how fast that happens is uncertain. It may commit the planet to the loss of most of its ice sheets and therefore dozens of metres of sea level rise. The acidification of ocean water from carbonic acid is another extremely grave threat to marine life and anything that depends on it.
I think you are confusing "alarming" and "alarmist".
At April 21, 2006 8:23 AM,
Anonymous said…
3oC warmer oceans will guarantee heat death of virtually all coral reef in the ocean and will commit us to several metres of sea level rise, though how fast that happens is uncertain. It may commit the planet to the loss of most of its ice sheets and therefore dozens of metres of sea level rise. The acidification of ocean water from carbonic acid is another extremely grave threat to marine life and anything that depends on it.
Horsefeathers. You have zero empirical evidence upon which to base these claims. It's all based on computer models, which aren't capable of accurately modelling the whole earth's ecosystem. GIGO.
Alarmist: A person who needlessly alarms or attempts to alarm others, as by inventing or spreading false or exaggerated rumors of impending danger or catastrophe.
Alarming: Exciting, or calculated to excite, alarm; causing apprehension of danger; as, an alarming crisis or report.
Alarmist is exactly what I meant.
At April 21, 2006 8:31 AM,
Anonymous said…
Such a long term prediction depends too much on human action to be able to predict.
Then what is the rationale for committing to drastic reductions in CO2 levels right now? How do we know that in 20 years time, technological developments will be such that the production of greenhouse gases will be drastically reduced?
Just to be clear, I'm not against studying climate change, or funding research into technology that can mitigate human effects on the environment. What I object to is the alarmist rhetoric that attempts to scare people based on flimsy or no evidence, usually with the intent of having governments implement coercive measures to limit greenhouse gas emissions. The cost/benefit tradeoff for taking the kinds of actions favored in the Kyoto accord are drastically out of whack (the costs are tremendous, immediate, and obvious, while the benefits are uncertain and far in the future).
All that aside, history does not support the notion that 2oC more warming (for a change of 3oC since pre industrial) in two centuries is modest, nor does time stop in 2100AD.
Are you telling me that you would pay any attention to policies implemented to effect the environment that were implemented in 1900? Why do you think our technological knowledge is going to be any less different from now in 2100 than 2000 was from 1900?
At April 21, 2006 9:47 AM,
coby said…
I said:
- 3oC warmer oceans = mass reef death
- 3oC warmer earth = very large sea level rise
- acidic oceans are threat to marine life
You say this is only based on models. Wrong.
The sea level and temperature relationship is based on observations of the past, specifically the Eemian interglacial whose temperatures we are just starting to match and whose sea levels were 4-6m higher and the climate a few million years ago whose temperatures we may reach by 2100 and sea levels were some 25m higher.
Acidification due to rising CO2 is simple chemistry. As for its possible impacts, they are already being observed in th degradation of shell formation in tiny marine organisms that are a major part of the food chain. The ramification of that do not take a model to understand. Also, check out what occured during the Paleocene-Eocene Thermal Maximum, a very similar event occured as to the perturbation we are now causing, the results are sobering.
Alarmist may be what you meant, but it is nevertheless incorrect.
At April 21, 2006 10:06 AM,
coby said…
I said: "Such a long term prediction depends too much on human action to be able to predict."
You replied: "Then what is the rationale for committing to drastic reductions in CO2 levels right now?"
I don't see the connection at all. But to answer the question is that the future depends on our actions and the danger is high CO2 levels, so the rationale is "avoid harm by ceasing dangerous actions".
We don't know what technology will develope, but it surely will develope faster through policy pressure. Examples of this are catalytic converters, anti-ping with unleaded gas technology and CFC replacements. In each case harmful effects were limited via policy and resulting market pressures lead to technological innovations.
If reduction of oil consumption is the only route forward right now, even if technology provides later for unrestrained burning, we will still have the benefit of learning how to conserve a precious and non-renewable resource. It is a clear win-win situation.
The alarm is not based on flimsy or non-existent evidence, I suggest you spend some time on the IPCC TAR. The case has only strengthen in very significant ways since that report was put together.
"The cost/benefit tradeoff for taking the kinds of actions favored in the Kyoto accord are drastically out of whack (the costs are tremendous, immediate, and obvious, while the benefits are uncertain and far in the future)."
Horsefeathers.
"Are you telling me that you would pay any attention to policies implemented to effect the environment that were implemented in 1900? Why do you think our technological knowledge is going to be any less different from now in 2100 than 2000 was from 1900?"
If those policies were stil necessary, yes, of course I would pay attention to them. Whatever technolgy brings us in the foreseeable future, keeping the CO2 concentration in the atmosphere from rising will remain a pertinent concern. If we find a way to burn coal as fast as we want with no CO2 emissions or other pollution, then burn away. Policies are aimed at goals and if new ways to meet the goals come up we will surely change the policies, but not the goals.
Things like Kyoto place targets on emissions, it does not mandate how a country must meet those targets, be it through new technology, efficiency, change in social priorities, sacrifice or what have you.
At November 15, 2006 8:53 PM,
Anonymous said…
coby - we need the entire original testomony from 1988 including the graph. Claiming that Hansen was right or wrong without the original source is kind of silly - isn't it?
At November 15, 2006 10:17 PM,
coby said…
Well, we have the paper and Hansen says he based his testimony on it and there are many accounts of that testimony that agree and Michaels has not denied what he did, so that seems good enough. If I were a lawyer suing Michaels I would of course get the testimony itself.
At December 16, 2006 1:19 PM,
Anonymous said…
From a summary (graphs included) of James Hansen's 1988 debate with Dr. Micheals at the Univeristy of Virginia.
"1. Empirical evidence: climate sensitivity to forcings"
http://www.giss.nasa.gov/edu/gwdebate/gwdebate.pdf
I'd like to say to Coby thank you for your opening blog entry stating your qualifications. Well done. I had some things to say to another blogger who boldly ranted(and aptly titled it so) about his skepticism with no facts, links, or qualifying remarks.
My qualifications are merely that I recently completed a research paper for a university class on Global Warming. However, I was limited to some basics, which is still more than I knew at the time. In other words, I'm more of a layman than it appears many other layman are at this point. I did go into my paper with an open mind and without a conclusion simply researching the obvious beginning areas. My discovering lead me to believe that ocean temperatures and specifically the methane prospect (http://www.newmediaexplorer.org/sepp/2005/02/01/global_warming_methane_could_be_far_worse_than_carbon_dioxide.htm
), as well as, cessation of thermohaline circulation are frightening propositions. (Although, I did not go into methane issues in my paper because it was only a 5 page research paper.)
However, my conclusion is simply this:
Global warming is a reality [based upon current effects]. Factors of global warming are increasingly obvious in shorter durations of time. Ice caps are melting, life cycles are threatened, drought and flooding are predominant, sea levels are rising and the Gulf Stream is weakening. Although the most drastic effects by human contributors may not be reached until closer to the end of this century, benefits of any changes we make now also would not be seen for many years to come. Therefore, it is important that we step up the priority because there will not be time to do so later. As the most advanced form of life on the planet, we have a responsibility and the knowledge to consider all factors, make changes and develop a plan for counter effects. In conclusion, each day that we continue to exploit our resources and environment is time poorly spent on a debt we will be unable to pay later.
The point of my post being (for serious skeptics) is: what will you be able to do about it if you are dead? Evidence will be left for the next age perhaps through your skeletal remains.
I'm not against the skeptic (with supporting arguments) because it provides for a healthy debate.
I am not for a lot of government intervention into our freedoms by any means, but at the same time, as the largest producer of waste in the world, the US has an obligation to, at the very least, consider the what ifs and not shut up their own scientists such as James Hansen and James Titus.
babs
At December 19, 2006 7:07 AM,
Anonymous said…
"Ice caps are melting"
They are melting in the Artic but not in Antartica which is cooling since 1980.
"drought and flooding are predominant"
"Predominant" compared to what please?
"sea levels are rising"
They are since we got out of the last ice age 20.000 years ago when the sea is 130 m below the current level and when carbon emission was not considered a problem. That is a mean rate of 6,5 mm/year compared to the present 2,6 mm/year.
"the Gulf Stream is weakening."
No, it's not true. The highly publicized results of a 30% weakening of the GS by Bryden last year has been refuted (see here). That you are not aware of this show that the public information is skewed in favor of alarmist news :
At December 19, 2006 11:25 AM,
coby said…
[Ice caps] are melting in the Artic but not in Antartica which is cooling since 1980.
What is your source for this? The antarctic overall has shown very little trend but the most recent results do in fact indicate warming overall. The antarctic pennisula has warmed a great deal and its glaciers hae receded dramatically. FWIW, models do not expect much different at this time, please see this article though I think the references are starting to be out of date. The most recent calculations of ice mass balance in the antarctic also do indicate loss of ice, though nothing close to the changes seen in the arctic sea ice and Greenland ice sheet.
[Sea levels] are [rising] since we got out of the last ice age 20.000 years ago when the sea is 130 m below the current level
This is a very weak argument. Sea level rose starting about 20K yrs ago, yes, but it stopped ~8K yrs ago. Since then until last century it was very stable, like the global climate. Read this article for a rebuttal to the "temperature has been rising for 20K yrs" version of that argument.
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