Unusual numbers in “Climate facts to warm to”
I came across Christopher Pearson’s recent article “Climate facts to warm to” today. In it, Mr Pearson takes the opportunity to strongly attack the concept of climate change and suggest that soon all manner of public figures will be rueing the day they publicly supported efforts to combat climate change and its effects.
His key assertion seems to rest on an interview with Jennifer Marohasy in which she states that global temperatures have plateaued this century.
That really got my attention. For global temperatures to have levelled out this last 7-8 years would be a noteworthy finding indeed. It wouldn’t necessarily mean that climate change was not real - any weather system as complex as our planets is going to show spikes and dips from the trend - but it would be worthy of analysis and note.
Unfortunately there were no references in the article for me to check the figures on. I visited Jennifer’s blog and was able to find some graphs and references to Roy Spencer’s work. Roy Spencer is a research scientist who has done a lot of work with climate measurements derived from satellites, and has a book out called “Climate Confusion” that attacks a lot of the science behind climate change.
He’s also quite famous for co-authoring a report showing that warming in the troposphere did not match current climate change models. At the time, this caused quite a stir, and was touted by many as the “death” of climate change theories. However, a later analysis revealed an error in the figures - the task of factoring in all the data sources was a complex one. The revised analysis that fixed this error did in fact show that warming in the troposphere matched climate models closely. You can read more about this in this New York Times article, or this more in-depth article at Skeptical Science.
But to return to the original point - although I could find some static images of graphs, I was curious to find the actual data showing a plateauing of temperature this century. So, using the amateur researcher’s best friend, I called on Google. While I couldn’t find the source of Roy Spencer (and Jennifer Marohasy’s) graph, I did find this great page from NASA concerned with GISS Surface Temperature Analysis.
The summary says it all:
“The year 2007 tied for second warmest in the period of instrumental data, behind the record warmth of 2005, in the Goddard Institute for Space Studies (GISS) analysis. 2007 tied 1998, which had leapt a remarkable 0.2°C above the prior record with the help of the “El Niño of the century”. The unusual warmth in 2007 is noteworthy because it occurs at a time when solar irradiance is at a minimum and the equatorial Pacific Ocean is in the cool phase of its natural El Niño-La Niña cycle.”
The site also features a graph that shows no sign of a plateau (a shrunken version shown above) - not surprising, given that 2005 was apparently the warmest year ever recorded! For those who are into numbers, you might also like this NASA web page, which gives a table of numbers from which you can calculate the average global temperature for any given year.
It may be there is another set of measurements that give the different set of numbers which Roy Spencer, Jennifer Marohasy and Christopher Pearson are so excited about. What would be useful is some sort of attribution for these numbers in the article for the readers to evaluate. Even better would be an analysis that explains how those numbers were derived and why they differ from the NASA figures that continue to show a warming trend.
(Graph sourced from http://data.giss.nasa.gov/gistemp/2007/)
Categories: current affairs, environment, skeptic
Tags: climate change, global warming, media, nasa, skeptic
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April 17th, 2008 at 10:42 am
The claims by Marohasy about global temperature leveling off or dropping are unfounded. A simple email to her source, Roy Spencer at NASA, can clear it up. Which is what I did. Roy says that Marohasy is confused. He states that the data is not from the much vaunted Aqua satellite project as Marohasy claimed, and is not global average but a much smaller sample of 20 degrees either side of the equator.
Paper published by Roy Spencer can be found here:
http://www.weatherquestions.com/Spencer_07GRL.pdf
Now for some clearly needed Ad hominem. Marohasy, the scientist who has misrepresented the information in the interview, appears to have published only a dozen scientific papers or so in areas such as biological control. Her expertise is clearly not climate. She has had a long association with banking, industry and anti-conservation environmental groups that advocate actions like whale hunting. Not the person I would be quoting on climate change.
Check out Marohasy’s web site:
http://www.jennifermarohasy.com/about.php
Finally, the author of the article, Pearson, complains about The Age leaving out some phrases that soften the claims of one of their climate change articles. Pearson has done the exact same thing in this article. See the quoted paragraph from the readily available transcript of the interview from the unashamedly right wing Counterpoint program on the Radio National web site.
http://www.abc.net.au/rn/counterpoint/stories/2008/2191714.htm
“Jennifer Marohasy: It is extraordinary, though I perhaps should pick you up on ‘global warming has stopped’. It has stopped for the last ten years, but that’s a very short timeframe. If you look over the last 100 years, it’s mostly been warming over the last 100 years but there was some cooling from 1940 through to 1975 and now there appears to be some cooling since 1998. But if you look at the longer timeframe, say, since the last glacial maximum, well, that’s going back, say, 16,000 years, then there actually has been significant warming, and sea levels of course have risen over 100 metres over this period. So the last eight to ten-year dip may just be a dip, and there may be continued warming into the future, or it could be the end of this interglacial warm period and we could go into another ice age. We don’t know what the future holds.”