I note John Tulloch’s comments (Urban heat islands, SN, 31 July 2012) on the global warming debate in which he draws our attention to recent evidence that the siting of temperature measuring devices in close proximity to growing “urban heat islands” may have distorted measurements of the rate of rise in temperature.
However while the trend might be revised (from + 0.309C/decade down to + 0.155 C/decade) it is still a rising trend.
There is also new work (confirming earlier studies) that oceanic algal blooms can withdraw massive amounts of atmospheric carbon dioxide, lowering global temperatures, and these can be seeded by iron dust (http://www.wired.com/wiredscience/2012/07/algae-ice-age-climate/ ).
So we can always grind up our cars as scrap iron when we run out of oil and dump that in the sea to induce global cooling. I wonder what we’ll be warming ourselves on by then.
Robin Barclay Edinburgh