Another biased report

ABC Science are running this Reuters report about a recent PNAS paper titled "Reconciling anthropogenic climate change with observed temperature 1998–2008" that finds there has been no global warming since 1998. Seems Geologists Ian Plimer and Bob Carter have been vindicated in their assessment of recent global temperature trends. Here's link to an article by Bob Carter from 2006.

"There IS a problem with global warming... it stopped in 1998" 12:01AM BST 09 Apr 2006.

"Consider the simple fact, drawn from the official temperature records of the Climate Research Unit at the University of East Anglia, that for the years 1998-2005 global average temperature did not increase (there was actually a slight decrease, though not at a rate that differs significantly from zero)." 

And Ian Plimer's conversation with ABC's Tony Jones in 2008:
TONY JONES: OK, let's look at some of the information. We don't have time to go through the whole book. Let's focus on one critical aspect of your thesis. In your book you state many, many times, that the planet has been cooling, not warming, in recent years, since 1998. I counted a dozen references in one chapter, they're arguably dozens throughout the book. This is fundamental to your whole argument, isn't it?

IAN PLIMER: No, it isn't. What is fundament to the argument - if we just take the last 2000 years. The planet was hot in Roman and Greek times. Then it cooled in the dark ages, then it warmed in the medieval warmth. Then it cooled in the little ice ages, and we are now, we've just come out of the little ice age. Is it any wonder that the planet has warmed up?

Climate Scientist Judy Curry provides the following critique on the paper on her blog Climate Etc...pity ABC did not seek to balance their report.

Science News is writing an article on this paper (haven’t spotted it yet-ED it's HERE).  Here is the complete comments I provided to the reporter via email:

This paper points out that global coal consumption (primarily from China) has increased significantly, although the dataset referred to shows an increase only since 2004-2007 (the period 1985-2003 was pretty stable).  The authors argue that the sulfates associated with this coal consumption have been sufficient to counter the greenhouse gas warming during the period 1998-2008, which is similar to the mechanism that has been invoked  to explain the cooling during the period 1940-1970.

I don’t find this explanation to be convincing because the increase in sulfates occurs only since 2004 (the solar signal is too small to make much difference).  Further, translating regional sulfate emission into global forcing isnt really appropriate, since atmospheric sulfate has too short of an atmospheric lifetime (owing to cloud and rain processes) to influence the global radiation balance.

 The alternative explanation is  natural internal variability associated with the ocean oscillations.  Since 1999, the Pacific Decadal Oscillation has been shifting from the warm phase (warm phase since 1976) to the cool phase, and has been mostly in the cool phase since 2007.   A cool PDO is associated with more frequent La Nina events, which are associated with globally cooler temperatures. The climate model studies cited by the authors do not do a convincing job of ruling out natural internal variability as an explanation, either for the cool period since 1998, and the earlier cool period during 1940-1970.

 In summary, the authors have put forward one possible explanation for the lack of warming, but an explanation associated with natural internal variability associated with the ocean oscillations is at least as plausible as the explanation put forward by the authors.