Among the issues most commonly discussed are individuality, the rights of the individual, the limits of legitimate government, morality, history, economics, government policy, science, business, education, health care, energy, and man-made global warming evaluations. My posts are aimed at intelligent and rational individuals, whose comments are very welcome.

"No matter how vast your knowledge or how modest, it is your own mind that has to acquire it." Ayn Rand

"Observe that the 'haves' are those who have freedom, and that it is freedom that the 'have-nots' have not." Ayn Rand

"The virtue involved in helping those one loves is not 'selflessness' or 'sacrifice', but integrity." Ayn Rand

24 December 2009

Claim that Half of Late 20th Century Temperature Rise is Caused by Land Use

Professor Brian Stone, City and Regional Planning Professor, of the Georgia Institute of Technology claims that half of the increase in temperature which has occurred since 1950 is due to land use changes, rather than due to greenhouse gas emissions.  The land use changes are largely those of city creation and expansion and the clearing of forests for crops.  His study is published in the journal of Environmental Science and Technology.

My expectation on this is that he is largely right, given that he is trying to explain land surface temperature data which shows temperature increases after 1950 which are half due to the fact that many weather stations are in urban and suburban areas and are therefore showing temperature increases due to the urban heat island effect and the remaining half is due to unfounded upward adjustments of the raw temperature measurements such as those we have discussed for the U.S., Australia, New Zealand, Northern Europe, Russia, and Alaska.  The impact on rural land surface temperatures of land use changes is modest, but perhaps not insignificant.  The impact on sea surface temperatures will almost certainly be negligible.  This is how I would lay my bets as a scientist deciding where to invest my own research efforts in any case.

No comments: