Monday, February 11, 2008

6 Degrees

Last night, National Geographic had 6 Degrees Could Change the World. It was interesting but I couldn't help but wonder what other facts they had wrong.

First, great prominence was given to NASA's Jim Hansen. As you may recall, calculations he did on the mean temperatures proved to be in error.

On Aug. 4, however, the well-known climate change skeptic and former mining executive Steven McIntyre — who previously challenged climatologist Michael Mann's 1998 finding that temperatures have increased rapidly since 1900 A.D., compared with the previous thousand years, forming a distinctive "hockey stick" temperature pattern — observed a strange jump in the U.S. data occurring around January 2000. He sent an e-mail to NASA about his observation, and the agency responded with an e-mail acknowledging a flaw in the calculations and thanking him for his help, he says. By Aug. 7, he says, the agency had removed the incorrect U.S. data from the GISS Web site and replaced it with corrected numbers for all 1,200 stations.

The issue didn't end there, however. The corrections made almost no difference to global temperature trends, NASA reported, while U.S. mean annual temperatures from 2000 to 2006 were all reduced by about 0.15 degrees Celsius. Most significantly for climate change skeptics, however, the year 1934 now edges out 1998 as the hottest year in the United States.

Scientists are saying the errors were minimal. But if basic data such as temperatures are not correlated correctly, how can we, the general public, have confidence that the computer models used to project global warming/change are correct?

In programming, there is the adage: Garbage in, garbage out. New studies have shown that clouds play a critical role in warming and cooling the earth. Reputable scientists who challenge the status quo of the doomsayers for climate warming/change do not seem willing to look at data that contradicts their findings.

Now two new studies have been published in the February 1 issue of Science showing that something is indeed going on in the tropics that is consistent with Lindzen's iris effect (though it does not confirm it). Researchers at two NASA institutes have found that the tropics have become less cloudy over the past 15 years. According to the paper by Junye Chen et al., "satellite observations suggest that the thermal radiation emitted by Earth to space increased by more than 5 watts per square meter, while reflected sunlight decreased by less than 2 watts per square meter, in the tropics over the period 1985-2000." In other words, on balance, more heat escaped into space than was added by the additional sunlight that fewer clouds let in. This process tends toward cooling down the atmosphere.

Why are these studies important? Because as the Lindzen study points out, "Whether the iris feedback ultimately proves as effective as our results suggest, the inability of existing models to replicate the relevant observations suggests the need for model improvement in an area potentially crucial to the determination of climate sensitivity." In other words, the current climate models may be missing important effects that would dramatically reduce their projections of future global warming.

One factor I don't remember ebbing discussed is sunspot activity. In 2004, sunspot activity was being reported as very active. New reports suggest sunspot activity is going quiet. Perhaps it is the sunspot activity that is impacting our climate more so than man's activity:

Looking back through sunspot records reveals many periods when the Sun's activity was high and low and in general they are related to warm and cool climatic periods. As well as the Little Ice Age, there was the weak Sun and the cold Iron Age, the active sun and the warm Bronze Age. Scientists cannot readily explain how the Sun's activity affects the Earth but it is an observational correlation that the Sun's moods have a climatic effect on the Earth.

Today's climate change consensus is that man-made greenhouse gases are warming the world and that we must act to curb them to reduce the projected temperature increase estimated at probably between 1.8C and 4.0C by the century's end. But throughout the 20th century, solar cycles had been increasing in strength. Almost everyone agrees that throughout most of the last century the solar influence was significant. Studies show that by the end of the 20th century the Sun's activity may have been at its highest for more than 8,000 years. Other solar parameters have been changing as well, such as the magnetic field the Sun sheds, which has almost doubled in the past century. But then things turned. In only the past decade or so the Sun has started a decline in activity, and the lateness of cycle 24 is an indicator.

The show talks about Hurricane Katrina. It managed to get one key fact wrong. The show stated New Orleans was hit directly by Hurricane Katrina. This is so patently false that it casts into doubt any of the other facts presented. If they cannot even manage to get that one fact correct, what others are wrong? Hurricane Katrina made its first landing in Buras Louisiana and then came ashore at Lakeshore Mississippi. The show did manage to state correctly that Katrina's storm surge played a role in the levee failures.

The ice sheets of Greenland were given much prominence. The most striking was the film of the rivers of water at the top of the ice sheet gouging a hole to the bottom of the ice sheet. At the beginning, the ice sheet was mentioned to be 1500 meters thick, but when the scientists measured the depth of the water tunnels, it was said to be 73 meters. What gives? Surely, the ice sheets hadn't melted that much or else coastal cities would already be under water.

It would be safe to assume that those readings were done at the margins of the ice sheet and not the interior. I found this study to be very interesting. It shows the interior ice sheet is actually growing and that there appear to be 11 year cycles, much like sunspots occur in 11 year cycles.

By combining tens of millions of data points from ERS-1 and ERS-2, the team determined spatial patterns of surface elevation variations and changes over an 11-year period.

The result is a mixed picture, with a net increase of 6.4 centimetres per year in the interior area above 1500 metres elevation. Below that altitude, the elevation-change rate is minus 2.0 cm per year, broadly matching reported thinning in the ice-sheet margins. The trend below 1500 metres however does not include the steeply-sloping marginal areas where current altimeter data are unusable.

The spatially averaged increase is 5.4 cm per year over the study area, when corrected for post-Ice Age uplift of the bedrock beneath the ice sheet. These results are remarkable because they are in contrast to previous scientific findings of balance in Greenland's high-elevation ice.

One good thing about shows like 6 Degrees, if you pay attention to the facts presented, it should make you question the science behind the conclusions. One thing that struck me was the pictures of the glacier that feeds the Ganges River. A quick google search shows that 1956 was a record year for low temperatures. Could it be the retreat of this glacier also corresponds to sunspot activity?

I agree that we all should make attempts to conserve as much as possible. But I think that there are more variables into global climate change than just the amount of CO2. Other shows have indicated the role of sulphuric acid produced by volcanoes, sunspot activity, cloud cover, and many other factors. Each of us should do our part to conserve water, fuel, and other natural resources.


satiricohen said...

Thanks for the informative write-up.
Have you seen the documentary called the great global warming swindle?

shira said...

You're welcome. And I haven't seen that link. I'll have to read it tonight. Thanks.