Met Office affirms its position on long-term global warming
Post Date: 08 January 2013
The Met Office has been forced to issue a statement clarifying its position on long-term global warming following an item on Radio 4's Today programme this morning.
The item said that the UK's weather forecasting bureau had revised its opinion on average global temperature increases up to 2017, to believe that they will not increase as much as previously thought, and that temperatures had flatlined. The news, derived from a decadal forecast statement, which is updated every year and was published last December on the organisation's website, had previously circulated on anti-anthropogenic global warming websites amongst climate change sceptics as "evidence" that global warming does not exist.
The statement says: "Global average temperature is expected to remain between 0.28 °C and 0.59 °C (90% confidence range) above the long-term (1971-2000) average during the period 2013-2017, with values most likely to be about 0.43 °C higher than average".
It says nothing about long-term temperature rises.
The new position statement, released this morning by the Met Office, clarifies any misconceptions by saying: "The updated decadal forecast is the first to make use of our latest climate model, HadGEM3. The fact that the new model predicts less warming, globally, for the coming five years does not necessarily tell us anything about long-term predictions of climate change for the coming century."
It adds that as science revises its understanding of short-term effects, for example from sun cycles, on longer term trends, predictions are bound to be modified.
"The Met Office is actively researching potential causes of the recent slowdown in global warming, including natural variability, the recent deep solar minimum, the influence of forcing from short-lived species, such as sulphate aerosol emissions, and the climate response to these forcings," the statement says.
Decadal forecasting relies on knowledge of the low frequency (multi-year) variability of the oceans and the response of the climate system to natural and human-induced forcings.
This is an extremely challenging area of research not least because long-term comprehensive observations of the ocean do not exist to help us understand how the global oceans behave over decadal and longer timescales.
The Met Office has been clear that these forecasts are for research use only.
It is unsurprising that climate change opponents would jump on announcements like this to support their cause, which is fundamentally anti-science.
Nevertheless, the Met Office remains convinced that, in a timeframe longer than five years, its predictions remain within the same parameters.
A leaked draft of the next IPPC report on climate change, to be published in the late summer, is in line with this and predicts "greater sea level rise than it did in 2007", "that we could see almost 9 °C of warming by 2300; and that "a large fraction of climate change is largely irreversible on human timescales", according to the New Scientist magazine.
The Met Office's 2013 annual global temperature forecast says "2013 is expected to be between 0.43 °C and 0.71 °C warmer than the long-term (1961-1990) global average of 14.0 °C".
It adds: "2012 is currently ranked the 9th warmest year on record. The global average temperature for 2012 falls well within the range predicted by the Met Office for 2012 of between 0.34 °C and 0.62 °C, with a most likely value of 0.48 °C above the long term average. This is consistent with the Met Office forecast statement that 2012 was expected to be warmer than 2011, but not as warm as the record year of 2010."
In addition, its review of the weather in 2012 said that the record amount of rainfall was due to an increase of about 0.7 °C in global temperatures since pre-industrial times. "From basic physics, this would equate to about a 4% increase in moisture in the atmosphere which means there is a greater potential for heavy rain," it says.
Story: David Thorpe, News Editor