I posted (here) about the rather strange way that the Met Office uses reference periods when it announces record breaking weather events. As New Year is the time when they make their annual global temperature forecast for the next twelve months, I thought that it would be worth looking at what they predicted for 2007, and then what they are predicting for 2008.
Here’s the Met Office’s first press release of 2007 issued last January:
4 January 2007
2007 – forecast to be the warmest year yet
2007 is likely to be the warmest year on record globally, beating the current record set in 1998, say climate-change experts at the Met Office.
Each January the Met Office, in conjunction with the University of East Anglia, issues a forecast of the global surface temperature for the coming year. The forecast takes into account known contributing factors, such as solar effects, El Niño, greenhouse gases concentrations and other multi-decadal influences. Over the previous seven years, the Met Office forecast of annual global temperature has proved remarkably accurate, with a mean forecast error size of just 0.06 °C.
Met Office global forecast for 2007
- Global temperature for 2007 is expected to be 0.54 °C above the long-term (1961-1990) average of 14.0 °C;
- There is a 60% probability that 2007 will be as warm or warmer than the current warmest year (1998 was +0.52 °C above the long-term 1961-1990 average).
The potential for a record 2007 arises partly from a moderate-strength El Niño already established in the Pacific, which is expected to persist through the first few months of 2007. The lag between El Niño and the full global surface temperature response means that the warming effect of El Niño is extended and therefore has a greater influence the global temperatures during the year.
Katie Hopkins from Met Office Consulting said: “This new information represents another warning that climate change is happening around the world. Our work in the climate change consultancy team applies Met Office research to help businesses mitigate against risk and adapt at a strategic level for success in the new environment.”
The reference to El Niño is important. These periodic and unpredictable convulsions in the Pacific Ocean’s surface temperatures can have a dramatic effect on climate across much of the world. A major El Niño event was partly responsible for the very high global temperatures of 1998. In fact about a third of the temperature anomaly that made that year the warmest recorded for the 20th century can be attributed to this effect. So the Met Office is relying on a perfectly natural, but unpredictable event to boost global temperatures towards a new record. But the problems with predictions, particularly if you base them on phenomena that are not well understood, is that things can go very badly wrong. Continue reading »
Recent Comments