Some people have asked me for clarification on a few points including what the head of the Intergovernmental Panel on Climate Change has said by way of the ‘temperature plateau this century’ and also have asked for more information on my qualifications.
Let’s start by re-looking at the available temperature data, as at least one blogger, Ken Parish, seems to not understand this data.
1. Are temperatures really cooling?
Over very long time periods (thousands of years) the earth experiences cycles of warming and cooling – indeed climate is always changing. The earth is currently in what is known as an interglacial warm period with temperatures warming, and sea levels rising by about 100 metres, during the last 16,000 years.
But there have been ups and downs. For example, there was cooling for several hundred years after the medieval warm period through to about 1900. Then there was warming until about 1945 followed by cooling through until 1975-76. The United Nation’s IPCC (Intergovernmental Panel on Climate Change) predicted in 1990 that there would be continuous warming well into this century driven by rising levels of carbon dioxide. But in fact there has been cooling again over the last decade.
Just two years ago, the Hadley Centre in the United Kingdom predicted that 2007 would be a record warm year – exceeding 1998 – but it turned out to be rather cool.
So to summarize, as I said in the radio interview: if you take 1998 as your point of reference there has been cooling, if you take 2002 as your point of reference there has been a temperature plateau. I also said in the interview that temperatures may start to rise again, or the earth could be about to enter another period of prolonged cooling – we could even be at the end of the current interglacial warm period.
2. What did the Head of the IPCC say?
According to an interview in January 2008 by Reuters:
“Rajendra Pachauri, the head of the U.N. Panel that shared the 2007 Nobel Peace Prize with former U.S. Vice President Al Gore, said he would look into the apparent temperature plateau so far this century.
“One would really have to see on the basis of some analysis what this really represents,” he told Reuters, adding “are there natural factors compensating?” for increases in greenhouse gases from human activities.
“He added that skeptics about a human role in climate change delighted in hints that temperatures might not be rising. “There are some people who would want to find every single excuse to say that this is all hogwash,” he said.
“[Amir] Delju, [senior scientific coordinator of the World Meteorological Organization’s (WMO) climate program,] said temperatures would have to be flat for several more years before a lack of new record years became significant.” [end of quote from Reuters]
3. Who is Jennifer Marohasy?
I have a Batchelor of Science and a PhD from the University of Queensland – my thesis was in insect ecology. I worked as a field biologist for many years and then in the late 1980s started critiquing environmental campaigns while I was environment manager for Canegrowers – I was concerned, in particular, that the World Wild Fund for Nature (WWF) was falsely suggesting science supported various unproven allegations relating to farming and the Great Barrier Reef. I then worked on Murray River water issues, again comparing allegations from environmentalists with the official statistics. I was forced to take an interest in global warming when Professor Tim Flannery made various public statements suggesting that the drought which gripped southern Australia for much of this century was unlikely to ever break because of carbon dioxide emissions. The issue of climate change now dominates much of the discussion at this weblog.
I have applied my training in the scientific method to understanding this issue. In particular I am only interested in the data – not what may or may not motivate commentary. Furthermore I am much more interested in observational data, rather than modelled output.
There are some people who may feel I am unqualified to comment in the area of climatology because my thesis topic was in ecology, however, much of my work for many years has simply been about understanding raw data/numbers and communicating this information in an honest and meaningful way – a PhD in a science discipline is a good formal training for this. I now describe myself as a biologist and a writer. Perhaps I could be best described as a science writer – but I have no formal training as a journalist, my training is as a scientist.