In a recent posting I said I would be commenting on a paper by Zhou and Tung (Zhou, J., and K. Tung, 2012: Deducing Multi-decadal Anthropogenic Global Warming Trends Using Multiple Regression Analysis. J. Atmos. Sci.doi:10.1175/JAS-D-12-0208.1, in press.)When I came across this paper I had mixed feelings. The paper says very similar things to those have I have been saying since January 2012: that

Anthropogenic Aerosols It has been pointed out that the model I described in my earlier post (Climate and the Atlantic Multidecadal Oscillation) ignored anthropogenic aerosols. Here I look at the effect of adding these into the model. DataThe data used were downloaded from http://data.giss.nasa.gov/modelforce/Fe.1880-2011.txt. They were used in J. Hansen, et al. (2007) "Climate simulations for 1880-2003

The following comes from a press release from the University of Reading (UK). "Natural climate variations could explain up to 30% of the loss in Arctic sea ice since the 1970s, scientists have found. "Sea ice coverage at the North Pole has shrunk dramatically over the past 40 years. The ice is now more than a third smaller each September following the summer melt than it was in the 1970s. This affects

1. Introduction I would guess that whoever you are, if you were to be told that all the 0.75 °C increase in global temperatures over the past 150 years was due to the increase in anthropogenic greenhouse gases but that temperatures over the next three decades would increase by only 0.1 °C you would have mixed reactions. If you were a sceptic you would scoff at the suggestion that greenhouse

On 16 May we had a post on temperatures in the Yamal peninsula. This is one of the sites much discussed for its influence on temperature reconstructions. In the earlier post we looked at measured temperature data from two stations. This time we have looked at a group of stations in and around the peninsula as shown in the following map. The data were from the station files used by the CRU for their

A recurring topic at ClimateAudit has been the use of tree ring data from the Yamal peninsula in Russia. Steve Mcintyre, the author of ClimateAudit, maintains that data from that area have been used selectively by researchers at the CRU to support the idea of a 'hockey stick' . At the RealClimate blog Gavin Schmidt claims that the results by the CRU were obtained after selection of samples following

One of the fundamentals of the consensus approach to climate change is that increasing temperature should lead to increasing water vapour and cloudiness. One type of data measured but not readily available is ‘hours of bright sun’. Initially it was measured by the Campbell-Stokes solar recorder, developed in middle of the 19th century. It uses a glass sphere to direct sunlight on to specially

We have earlier commented on trends in temperature.  (When is a trend not a trend?) Here we look quite simply at the 30-year trend line from three different temperature data sets and a 23-model ensemble hind-cast/projection. The trends were calculated using LINEST function in Excel. The year shown in the chart is the final year of each 30-year regression period. As can be seen the 30-year trend

The Georgia Institute of Technology has recently released details of a study of the relationship between Arctic Sea Ice and Northern Hemisphere Snow Cover.  The press release summarises it as “The researchers analyzed observational data collected between 1979 and 2010 and found that a decrease in autumn Arctic sea ice of 1 million square kilometers -- the size of the surface area of Egypt --

The realclimate.org blog has a thread posted by Barry Bickmore related to an article which appeared in the Wall Street Journal (WSJ). The original article was written by a group of eminent scientists with little specific expertise in the science of climate change. To summarise in over-simplistic terms they said that they could accept Anthropogenic Global Warming (AGW) but not Catastrophic Anthropogenic