Climategate continued...

In continuation of yesterday's post, I thought it was timely to discuss the recent BBC interview with Phil Jones. Jones resigned from his position as head of the University of East Anglia's Climatic Research Unit (CRU) after his scandalous emails leaked to the media.

The full Q&A from the Jones interview is accessible at the following link:

http://news.bbc.co.uk/2/hi/science/nature/8511670.stm

The most pertinent data presented in this feature story are the following warming trends for four different periods since 1860:
Period______Length___Trend (Degree C/decade)__Significance
1860-1880_____21_____0.163____________________Yes
1910-1940_____31_____0.15 ____________________Yes
1975-1998_____24_____0.166____________________Yes
1975-2009_____35_____0.161____________________Yes

Clearly, there have been four statistically significant periods of warming since the pre-industrial 1860-1880 time frame.

Jones also acknowledged that the rate of warming from 1995 to the current day (a 15 year period) was 0.12C. Although the trend is smaller by 0.3-0.4C, Jones says the short length of this time period means that this reduced trend does not yet meet the 95% significance level. But, it will be interesting to see what happens to this rate in 5 years time.

In conclusion, Jones's interpretation of the data is that the observed warming is man-made because volcanic and solar activity records can not explain the temperature increases in these 4 periods. However, I wonder what contribution heat transfer from within the earth's core could do this system and what those measurements look like. Alternatively, there could simply be other factors that have not been discovered yet that could account for these warming periods.

My feeling, as a scientist, is that you should never over-interpret your data and make statements that the data don't support. Therefore, I personally would not stake my professional reputation on a claim that these trends are man-made merely because we currently don't know yet what the real force driving the system is. Even I, in my 10 years of research experience, have learned that good science is well controlled and that interpretation of the data should be used to make narrow claims clearly substantiated by the data. To date, there has been no irrefutable evidence that man has acted and the global temperature has responded to that action.

Furthermore, there are clearly periods between the four warming periods mentioned in the BBC interview. I wonder what happened to the trends in these periods. Was there cooling or steady warming but at a lesser rate?

Speaking of cooling, Jones admits in the interview that from 2002 to the present, we have not been warming. In reality, we have been cooling for the last 8 years. Yes, the data have shown a cooling rate of -0.12C/decade. But once again, this period is too short to reach a 95% significance level. But, this SHOCKED me given that all anyone hears is that we're warming, warming and warming.

I think my final words on this issue are that 1) we have times of warming and cooling and 2) we have not yet identified the precise factors that have caused each warming trend.