date: Mon, 30 Mar 2009 16:08:47 +0100 from: "Parker, David" subject: RE: [Fwd: Chinese urban heat island effects] to: "Phil Jones" Phil Thanks - I've saved this into a safe place! David David Parker, Climate Research scientist Met Office Hadley Centre FitzRoy Road Exeter Devon EX1 3PB United Kingdom Tel: +44 (0)1392 886649 Fax: +44 (0)1392 885681 Email: david.parker@metoffice.gov.uk Website: www.metoffice.gov.uk See our guide to climate change at [1]http://www.metoffice.gov.uk/climatechange/guide/ ___________________________________________________________________________________________ From: Phil Jones [mailto:p.jones@uea.ac.uk] Sent: Monday, March 30, 2009 2:50 PM To: Parker, David Subject: RE: [Fwd: Chinese urban heat island effects] David, surfacestations.org seem to have picked this up a few weeks ago, when they made me the Director of the Hadley Centre - a job that I know doesn't exist! I was asked by someone at DECC on Friday to write a few sentences to help them respond to the following question, which came to Ed Milliband. You'd better not pass this on to anyone, but this is what I sent back. I don't know, if any of what I said below, was used. The reply had to sent today by noon, but I didn't hear back from anyone at DECC this morning. I got the impression that there were other questions/issues that DECC didn't send me. Cheers Phil What the questioner asked: Surface records exaggerate warming, due to urban encroachment on recording stations. Satellite records (available only since 1979) agree with stations distant from towns that temperatures have been growing much slower than is alleged by alarmists. Indeed, temperatures in the USA (the only reliable data series of any large land mass) were as high in the 30s as in the 90s. Even Hansen accepts this. The IPCC `correction' for this `heat island' is inadequate being largely based on unreliable Chinese records. The Director of the Met Office's Hadley Centre finally admitted this last autumn. My reply Every sentence in the above is wrong! There is more than one satellite record of MSU temperatures since 1979. They are almost certainly referring to the University of Alabama at Hunstville (UAH) dataset. There is also a dataset developed at Remote Sensing Systems (RSS, also in the USA) that shows more warming than UAH since 1979. Differences relate to the way numerous issues with the sensors and the satellite orbits have been adjusted for. The MSU instruments on these polar-orbiting satellites also measure temperature in the lower troposphere (centred about 700hPa) so are not directly comparable with what is measured at the surface. The best discussion of all this is in Ch 3 of 2007 IPCC AR4 (Section 3.4.1.2 and also Figure 3.17). The USA is not the only region to have good reliable series. It is the most studied record, only because the data are more freely available than elsewhere and there are a lot of scientists there. There are excellent records also across Europe, Canada, Australia, New Zealand, Japan and Russia, and they are considerably longer in Europe than the USA. Although coverage could be better in other regions of the world, all records from across world have been assessed for long-term homogeneity (including the effects of urbanization). The reference to Jim Hansen indicates that they place great emphasis on the records produced by GISS. There is another US dataset (developed by NCDC in Asheville), which I think is better and this has the contiguous US (lower 48 states) warmer in the 1990s compared to the 1930s. The CRUTEM3 data (the land component of HadCRUT3) agree better with the NCDC data than it does with GISS. A figure from AR4 to illustrate this is Fig 9.12 from Ch 9. This shows observed decadal mean temperatures since 1900 for three parts of North America (west, central and east) and all show that the 1990s was the warmest decade of the 20th century. IPCC doesn't have a correction, just like it doesn't have a data set or a climate model. IPCC assesses the scientific literature, it doesn't do research. The penultimate sentence refers to a recent paper (Jones et al., 2008). This looks at urbanization issues across China. This paper shows that urban-related warming is about 0.1 deg C/decade (for the period 1951-2004). Accounting for this, the remaining warming is 0.81 deg C over the period from 1951-2004. Combining these two bits of information means that 60% of the warming is not due to urban effects. This result is just for China, and cannot be applied elsewhere in the world. The paper shows, for example, that there is no urban-related warming at sites in the centres of London and Vienna. The contrast between the effects in China and those in London and Vienna highlight the fact that urban-related warming cannot be assumed to be occurring just based on a city's population. It is imperative to look at the data and compare urban with rural sites. AR4 of IPCC referred to several studies which looked at the effect of urbanization during the last 50-70 years. These studies include Parker (2004, 2006) and Peterson and Owen (2005), the latter showing hardly any urban-related warming across the contiguous United States (see this in Fig 3.3 of AR4). The Jones et al. (2008) study does not conflict with the earlier Jones et al. (1990) study, but instead confirms its findings, which were based on the 1954-1983 period. Figures 6 and 7 clearly show that much of the temperature rise across China has occurred since the mid-1980s, the period after the 1990 study. Finally, the paper gives the affiliation of the first two authors, namely the Climatic Research Unit at the University of East Anglia. The first author is not the Director of the Hadley Centre at the Met Office. In fact, no such position actually exists. References Jones, P.D., Lister, D.H. and Li, Q., 2008: Urbanization effects in large-scale temperature records, with an emphasis on China. J. Geophys. Res. 113, D16122, doi:10.1029/2008/JD009916. Jones, P.D., P.Ya. Groisman, M. Coughlan, N. Plummer, W.-C. Wang and T.R. Karl, 1990: Assessment of urbanization effects in time series of surface air temperature over land. Nature 347, 169-172. Parker, D.E., 2004: Large-scale warming is not urban. Nature, 432, 290-290. Parker, D.E., 2006: A demonstration that large-scale warming is not urban. J. Climate, 19, 2882-2895. Peterson, T.C. and T.W. Owen, 2005: Urban heat island assessment: Metadata are important. J. Climate, 18, 2637-2646. At 14:17 30/03/2009, you wrote: Barry No, we have not changed our estimates. We already knew that China was undergoing urbanisation, more so than other parts of the world. 0.1°C per decade urban warming since 1951 over China would still translate to a very small influence on the global trend. Jones et al also noted that some Western cities are no longer undergoing urban warming so they are contributing zero urban-warming trend in recent decades. Many other parts of the world have rural stations, and 70% of the Earth's surface is unaffected by cities because it is ocean. David David Parker, Climate Research scientist Met Office Hadley Centre FitzRoy Road Exeter Devon EX1 3PB United Kingdom Tel: +44 (0)1392 886649 Fax: +44 (0)1392 885681 Email: david.parker@metoffice.gov.uk Website: [2]www.metoffice.gov.uk See our guide to climate change at [3]http://www.metoffice.gov.uk/climatechange/guide/ -----Original Message----- From: Gromett, Barry On Behalf Of Press Office Sent: Monday, March 30, 2009 1:35 PM To: Parker, David Subject: FW: [Fwd: Chinese urban heat island effects] David Do you have any comment on this? Thanks very much Barry -----Original Message----- From: David Appell [[4] mailto:appell@nasw.org] Sent: 29 March 2009 02:25 To: Press Office Subject: [Fwd: Chinese urban heat island effects] -------- Original Message -------- Subject: Chinese urban heat island effects Date: Mon, 23 Mar 2009 17:59:57 -0700 From: David Appell Reply-To: appell@nasw.org To: pressoffice@metoffice.gov.uk Hello. Did the revision of Chinese Urban Heat Island effects in the 2008 paper by PD Jones et al (Jones, P. D., D. H. Lister, and Q. Li (2008), Urbanization effects in large-scale temperature records, with an emphasis on China, J. Geophys. Res., 113, D16122, doi:10.1029/2008JD009916) have any effect on overall global temperatures in any of your temperature time series (especially HadCRUT3)? Thank you, David -- David Appell, freelance science journalist e: appell@nasw.org p: 503-975-5614 w: [5]http://www.nasw.org/users/appell m: St. Helens, OR -- David Appell, freelance science journalist e: appell@nasw.org p: 503-975-5614 w: [6]http://www.nasw.org/users/appell m: St. Helens, OR Prof. Phil Jones Climatic Research Unit Telephone +44 (0) 1603 592090 School of Environmental Sciences Fax +44 (0) 1603 507784 University of East Anglia Norwich Email p.jones@uea.ac.uk NR4 7TJ UK ----------------------------------------------------------------------------