Thursday, May 14, 2009

Urban heat

I believe I was reading The Satanic Gases when I came across an interesting explanation for the rise in temperature readings used as evidence of climate change -- urban development. It's basically a variation on the urban heat island effect.

Let's say you set up a temperature guage in a pastoral, rural location. Years go by and development takes place. Asphalt gets spread, concrete is poured and buildings replace lush fields and shady trees. Given that such things tend to trap heat it would logically raise the heat by a slight amount over what it might overwise have been. As this graph illustrates even an increase in half a degree can be considered a big deal:

I thought about that when I read this interview with John Christy, a climatologist that does not accept money from the oil industry to fund his research. Christy is a proponent of the heat effect theory which is nicely summarized here:
His most controversial argument is that the surface temperature readings upon which global warming theory is built have been distorted by urbanization. Due to the solar heat captured by bricks and pavement and due to the changing wind patterns caused by large buildings, a weather station placed in a rural village in 1900 will inevitably show higher temperature readings if that village has, over time, been transformed into small city or a suburban shopping district, Christy says.
The only way to control for such surface distortions is by measuring atmospheric temperatures. And when Christy and his co-researcher Roy Spencer, a former NASA scientist now teaching at UA-Huntsville, began analyzing temperature readings from NOAA and NASA satellites, they found much slighter increases in atmospheric temperatures than what was being recorded on the surface. Clark and Spencer also found that nearly all the increases in average surface temperatures are related to nighttime readings - which makes sense if bricks and pavement are in fact retaining heat that would otherwise be dispersed.

In testimony to the House Ways and Means Committee in February, Christy displayed a chart showing central California temperature trends for both the developed San Joaquin Valley and the largely undeveloped Sierra foothills. "The daytime temperatures of both regions show virtually no change over the past 100 years, while the nighttime temperatures indicate the developed Valley has warmed significantly while the undeveloped Sierra foothills have not," Christy told the committee.
Global warming may very well be occurring. But I remain unconvinced about the contributions of mankind to any such phenomenon, it's alleged severity or the cost-benefit of most of the proposed solutions. Indeed, as Christy says:
The problem is that the solutions being offered don't provide any detectable relief from this so-called catastrophe. Congress is now discussing an 80% reduction in U.S. greenhouse emissions by 2050. That's basically the equivalent of building 1,000 new nuclear power plants all operating by 2020. Now I'm all in favor of nuclear energy, but that would affect the global temperature by only seven-hundredths of a degree by 2050 and fifteen hundredths by 2100. We wouldn't even notice it.
When confronted with hysteria and doom mongering I believe the best policy is to discount it, be that with regard to the rantings of Al Gore about climate change or those on the right who think that Iranian possession of nuclear weapons guarantees a new holocaust.

1 comment:

Josh said...

Check out

Their goal seems to be to review every surface station in the USHCN that is used to track surface temperature.

They have found many that violate the stated rules for where to place temperature stations (some are on airport grounds near runways). Other locations show significant urban development around the stations.

The Climate Change debate is quite interesting because even the baseline claim that the globe is warming is a subjective assertion and not a fact. Personally I see evidence that the globe was warming for roughly 20 years ending a few years ago and is now cooling. However, there's serious uncertainty as to how much given the accuracy and methods used to calculate global temperatures.