Tuesday, October 4, 2011

Climate change science history

A question at the question place regarded this history of climate change science.  See that link for the full question.  Here's my response, which over-ran the blog comment length limit there.

On the historical link side, the best single source is Spencer Weart's _The Discovery of Global Warming_ http://www.aip.org/history/climate/index.htm  I think he under-rates the significance of G. S. Callendar's work in the 1930s-50s, but that's my take and I haven't yet written it up formally.  It's an idea I've had, to do so.  Unfortunately, a lot of Weart's work will probably pass your students' level.  But you should be fine with it yourself and translate suitably to your students.

A different matter for your middle schoolers is the time scale of the history.  Perhaps combine this with a project to collect family history?

I'll take your students as being about 11. Let's go with 30 years per generation, which is, at least, fairly accurate for my family.  That means your kids born in about 2000, parents about 1970, grandparents in 1940, great-grandparents in 1910, great-great grandparents in 1880, great-great-great grandparents (g3 grandparents) in 1850, and g4 grandparents in 1820.

The history is:
When your students' g4 grandparents were pre-school age, Fourier realized and documented that the greenhouse effect (the name for it now, the name didn't exist then) existed.  That the earth was warmer than it would be if the atmosphere didn't do anything to retain heat to the earth's surface.  1824-1827.

When your students' g3 grandparents were middle school age, Tyndall showed that water vapor, carbon dioxide, and some other gases, were greenhouse gases.  1859-1861.

When their great-great grandparents were about to graduate from high school, Arrhenius showed that doubling the atmospheric CO2 levels could lead to about a 4 C warming, and that the warming would be stronger towards the poles than the equator.  Both are still considered reasonable predictions, and the latter is now well-observed.  1896.

Around the time their great-grandparents were being born, Angstrom made his error regarding saturation.  The error was to think that because the band centers saturated, that increased CO2 and water vapor could not increase the earth's temperature.  This was wrong because he ignored the fact that there is more than band centers involved.  The off-center parts can give continued warming, even while the centers are saturated.

During their grandparents' early lives (and somewhat before), Callendar was at work, documenting that CO2 levels had risen significantly (he was right, but the objection to his work was also correct -- this is one of the things I want to document properly), that the rise was from human activity, and that meaningful-to-humans climate change can be expected to result.  (1938 and following).

As your students' grandparents were graduating from high school and starting to work, Ralph Keeling started observing atmospheric CO2 levels on a regular and reliable basis.  Plass conducted his acceptable-to-modern-scientists computation of CO2-induced climate changes.  The international geophysical year was held and first earth-observing satellites were launched.  (1956-1958)

When your children's parents were younger than your children, the earth experienced its last month that was colder than the 20th century average (in 1976).  Your children have never experienced a year when the global mean temperature was colder than the 20th century average.  The younger parents never have either.

1988 was something of a watershed year in climate policy, if not the science.  1987-8 was a particularly hot year in the US, and a major drought across the US corn belt (for that time, these days it would be unremarkable, or even a rather cool year).  In 1988, Jim Hansen testified to Congress about climate change.  One part of that even was that the Whitehouse edited his testimony about the science.  The second being that Hansen was predicting that the signature of human-induced climate change would soon come out of the noise.  I thought he was ahead of the evidence at the time.  He turned out to be correct.  But the precedent of politicians trying to (and often being successful) in editing what science was presented was set.

Since 1988, there has (I would say) been little change in the public knowledge of the science in the US on climate change.  Your middle schoolers don't really hear much more than their parents did.  I have some late 80's, early 90's general press articles on climate, and they could all still be published as-is today.

Another thing I'll point out from the history:  The existence of a greenhouse effect was shown long before we knew what gases were greenhouse gases.  We knew what gases were greenhouse gases long before we knew that humans could significantly change climate by changing greenhouse gas levels.  And (not mentioned above) at the time it was discovered, it was considered (Arrhenius) a beneficial thing.  He lived in a very cold climate.


Kooiti Masuda said...

Observations of CO2 concentration during IGY was made by Charles David Keeling. Ralph is his son and a living expert of the issue at present.

Anonymous said...

I'd also recommend "The Warming Papers" for a compendium of some of the most important papers in climate science history, along with some insightful commentary on them...


Paul D said...

I created an interactive application with John Cook on this subject. It is really designed to show the amount of research on climate related subjects carried out over time. Moving the slider changes the year. Here is the URL:


Another interesting article in Physics Today shows that Climate Science is following similar historical patterns in science in which the public eventually accepts the findings.


Belette said...

> I think he under-rates

I think Weart is very US-centric. But that may just be a European viewpoint.

jg said...

I have to second Paul's link to the Physics Today article. At the end of the article, there's a nice timeline comparing the time involved in accepting various revolutionary scientific theories, including climate change. I also like Paul's visual comparison of the literature; thanks for sharing it's location -- I had lost track of it.
Another related skepticalScience project is this recent post on the common use of citing Galileo in defense of anti-concensus views of climate change: Modern scientists... This article has a summary of the scientific achievements and a timeline.

The timeline is a greatly abridged version of one that has a lot more gratuitous visuals; the more embellished version is here:
Climate Science Milestones


Anonymous said...

Interesting anecdote - the greenhouse effect of CO2 may have been demonstrated 3 years prior to Tyndall by one Eunice Foote.


I was able to verify the source online.


Robert Grumbine said...

Thanks barry! I'll take it up as a post once I have a chance to read the full write-up.

Anonymous said...

I hope you do a write-up on that, Robert. I'm attached to the story for some reason (probably to do with women in science at a time when it was difficult for women to participate) and have been slipping it in very occasionally at the climate blogs to mixed reviews.

I've traded a couple of emails with the author of the monograph and asked him if I could pass it around. He said yes, and also,

"I stumbled on to this material several years ago by accident after acquiring the book as an impulse purchase in a used book store. I decided to put together the short paper and post it in an on-line journal because I felt it was the best way to provide proper credit to an unknown researcher and make the information available to others.

As I got into the biographical background, I realized that it really needed to be book-length considering the celebrity status of almost everyone involved. That is a project that I do not intend to tackle."

Spencer Weart replied to an email from me saying that he was not sure how work that was not submitted formally should be listed in a history of science, but agreed that acknowledging this anecdote wasn't inappropriate, suggesting that he might include it at his history of climate science web site when he next updates.

There. I've let the bee in my bonnet have its buzz.

Best regards,


Hank Roberts said...

Recommending -- from the AGU videos, Ben Santer on Steve Schneider.

He begins with a memorial -- Steve Schneider is part of history.

He goes on to a teaching story.

CG43G : AGU Fall Meeting 2011

Starting at about minute 17:00 he gives the specific example of rebutting Prof. Happer's testimony, given to a Congressional hearing, claiming that global warming stopped in 1998:

1) can human models simulate such 10-year hiatus periods, and
2) if you look at the full 32-year satellite period and the warming of approximately half a degree Celsius, is that unusual.

Clear explanation, clear slides.