Email 3563, April 2009, Phil Jones on his belief that UHI isn't an issue: "I could use the St. James's Park record in the global T calculations. It wouldn't make any difference anyway"

Email 3563

I wrote the paper for two reasons: 1. To show that for London, the temperature in the centre is not getting any higher than in rural areas. Used much more data than anyone else. I did have to get some data digitized. I could use the St. James's Park record in the global T calculations. It wouldn't make any difference anyway, but the combination is with anomalies. Even people I used to think were good, think all city records are affected and shouldn't be used. 2. There is a widespread belief that in the future, the temperatures in London will rise even higher than the increase elsewhere in SE England. I don't know where this comes from, but almost everyone who says they have thought about it thinks so. The HC have run RCMs for Europe with cities in with an urban tiling scheme to try to simulate a city. They also add excess heat (25 and 50 w/m-2) in over the city. When the comparisons are done properly, there is no significant difference between squares in the centre and on the periphery. The HC always show the effect on conducive days! City centres will pass certain thresholds more regularly than rural areas, but that is all. Many people still think that if someone shows an 8 deg C difference on a single day or even at a single hour between a city centre site and a rural one, this is the size of the UHI! I know it's stupid, but I keep hearing this. I just wanted something for idiots like this to read.