Sunday, July 11, 2010

Global Warming vs AGW

Eugene Robinson, appearing in today's Register-Guard, considers the debate on global warming to be over. We should now proceed to the debate on how to deal with it. I'd be perfectly happy, except that warmists shut down any discussion of alternatives to their apocalyptic vision.

But leaving that aside, the debate is not really over warming, it's over manmade warming and specifically over the impact of CO2 in the atmosphere. NASA has a Key Climate Indicators site where they should a number of interesting graphs. One of these is temperature. It does in fact show a much steeper rise over the past 30 years than during the 30 that preceded. CO2 is also much higher. This could be taken as an indication of causation.

However, looking somewhat left on the same graph, we find the period 1910 to 1940. Also 30 years, also showing a rise of about .5 C, however without the corresponding CO2 concentrations.

It's probably getting a bit warmer. It has been getting warmer for the past two and a half centuries, since the end of the Little Ice Age. Still farther back in time, it used to be warmer than then and maybe warmer than now. At the point that science can explain why it's now CO2 and not the same factors that have played out before, then maybe the science will be settled. Not before.

3 comments:

Dan Pangburn said...

From 2001 through 2009 the atmospheric CO2 increased by 18% of the total increase from 1800 to 2001 while the average global temperature has not increased significantly and the trend through 2009 is down. Research, with latest findings regarding projected temperature trends is reported at http://climaterealists.com/index.php?tid=145&linkbox=true. It presents a rational equation that accurately calculates the average global temperatures since 1895 with a coefficient of determination of 0.87. That means that it explains 87% of the measured temperatures. The best that GCMs have done is less than 80%. The equation predicts that the trend of average global temperatures will decline. The above link and sub links, including links to the temperature data reported by the five reporting agencies, track the data back to the published credible sources. It will be interesting to observe what happens as the CO2 continues to increase and the average global temperature does not.

Rob Spooner said...

Mr. Pangborn suffers from the same illusion as the warmists. Predicting the past is not useful. By juggling coefficients and selecting variables, you can always match the past to within any degree of accuracy you wish. Recall that Dikpati's 2006 predictions for Solar Cycle 24 were based on a model that had been 97% accurate in predicting the previous N (8?) cycles, but collapsed spectacularly the first time it attempted to predict the future.

The world is full of computer models that look backward. Wake me up when one of them predicts the future accurately and repeatedly.

Dan Pangburn said...

Spooner's comments are not relevant.

As discussed extensively on pages 5 and 6 at http://climaterealists.com/attachments/database/ClimateChangeMistake2.pdf “Although GCMs are pretty good at predicting weather for up to a few days they are useless for predicting climate for years.”. This work has been available on line since 24 Feb, 2010.

There are two sources of uncertainty in the present analysis.
The first uncertainty is how much longer ESST will continue to do what it has done for the last 114 years. The projections assume that the ESST pattern will not change significantly for another 27 years.

The second uncertainty is in what the sunspot numbers will be. Two projections are given that include allowance for the calculated CO2 influence through 2009. One of these projections assumes that there are few to no sunspots, like the Maunder Minimum. The other projection assumes that the future sunspot numbers will be similar to the years following 1913. That is the most recent period when the sun was as quiet for as long as it has been this last solar minimum.