Excerpt of an article from the New Scientist, 01 December 2008 by Mark Buchanan (h/t to Richard Hegarty)
EVEN if we turn to clean energy to reduce carbon emissions, the planet might carry on warming anyway due to the heat released into the environment by our ever-increasing consumption of energy.
This picture, taken with a thermal imaging camera, reveals how much heat is being emitted by City Hall in London (Image: National Pictures)
That’s the contentious possibility raised by Nick Cowern and Chihak Ahn of the School of Electrical, Electronic and Computer Engineering at Newcastle University, UK. They argue that human energy consumption could begin to contribute significantly to global warming a century from now.
Cowern and Ahn considered an emissions scenario proposed by James Hansen of the Goddard Institute for Space Studies in New York, and others. Under this scenario, which envisages greenhouse gases being cut significantly through phasing out coal over the next 40 years, Cowern and Ahn calculate that the greenhouse effect will start to diminish by 2050, stabilising the climate.
Read more here
Consider then UHI, and my recent measurement of a temperature transect from Reno, NV
Here is the result of my South to North transect driving Virgina Street overlaid on a Google Earth image oriented to match the timeline of the transect:
Click for larger image
It seems clear that waste heat is already having an effect, because the UHI bubble from Reno has been shown by NOAA to affect the USHCN weather station there, which caused them to move the station once. They even include this in their own training manual.
What was amazing is that they’d already determined that there were significant problems with this USHCN station placement that contributed a significant warming bias to the record.
In fact, the National Weather Service includes the UHI factor in one of it’s training course ( NOAA Professional Competency Unit 6 ) using Reno, NV and Baltimore, MD as examples. The Reno station had to be moved because it was producing an erroneous record, and the Baltimore station has so much bias (because it existed on a rooftop of a downtown building) that they simply closed it in 1999.
From that manual:
Reno’s busy urban airport has seen the growth of an urban heat bubble on its north end.
The corresponding graph of mean annual minimum temperature (average of 365 nighttime
minimums each year) has as a consequence been steadily rising. When the new
ASOS sensor was installed, the site was moved to the much cooler south end of the
runway. Nearby records indicate that the two cool post-ASOS years should have been
warmer rather than cooler. When air traffic controllers asked for a location not so close
to nearby trees (for better wind readings), the station was moved back. The first move
was documented, the second was not. The climate record shows both the steady warming
of the site, as well as the big difference in overnight temperature between one end of this
flat and seemingly homogeneous setting, an observation borne out by automobile
traverses around the airport at night.
They were also kind enough to provide a photo essay of their own as well as a graph. You can click the aerial photo to get a Google Earth interactive view of the area.
This is NOAA’s graph showing the changes to the official climate record when they made station moves: