BBC News Online: Sci/Tech

Record warm start to 2002

Surface temperature variations in the Arabian Sea: Satellites see more than ships can

UK scientists say the last three months were globally the warmest January, February and March since records began.

They are also the second-warmest consecutive three months ever recorded.

Worldwide temperatures were 0.71 Celsius above the 1961-1990 average.

The scientists say it is significant that the record was broken in the absence of any warming influence from El Nino, the climate disturbance that originates in the Pacific.

El Ninos, which occur roughly every four years, are associated with increases in global temperatures.

Dr Geoff Jenkins, of the UK Government's Hadley Centre for Climate Prediction and Research, said: "These three months were the warmest January, February and March since records began in 1860.

No outside help

"Proxy records, for instance from tree rings, suggest they are in fact the warmest for a thousand years.

"Previous records have chiefly been broken during an El Nino, but this has happened in a slightly cool period."

The only consecutive three months warmer than the last three were February, March and April 1998, during a marked El Nino.

El Ninos occur when a huge mass of warm water builds up in the western Pacific and moves eastwards to the normally colder waters off the coast of South America, with widespread effects on weather in many parts of the world.

Dr Jenkins was speaking at the launch of a report, Climate Change Scenarios for the United Kingdom, prepared by the Hadley Centre and the Tyndall Centre for Climate Change Research.

The report refines an earlier set of predictions published four years ago.

It explores four possible impact scenarios, based on low, medium-low, medium-high and high emissions of the gases many scientists believe are exacerbating the climate's natural variability.

Snow a distant memory

Some scientists argue that human activities are irrelevant to climate change, and that attempts to reduce any impact are misconceived.

The report includes predictions that by the 2080s:

• annual average temperatures across the UK may rise by between 2 C (low) and 3.5 C (high)
• warmer summers will become more frequent and very cold winters increasingly rare
• winters will become wetter, summers perhaps drier, and under the high emissions scenario summer soil moisture across much of England could be 40% less, with serious implications for farming
• snowfall across the UK will decrease: average reductions over Scotland could range from 60% to 90% (high)
• relative sea level will go on rising around most of the UK: it could rise by between 26 and 86 cm (10 to 34 inches) in southeast England
• in some places the probability of extremes of sea level (for instance, during a storm surge) in any given year could rise from about 2% to 90% (high)
• the Gulf Stream may weaken, but probably not enough to cool the UK during this century.

"But we now have to worry about ourselves as well. Some of the impacts we will not be able to avert.

"The changes are already locked into the climate system and cannot be reversed."

Dr Jenkins told BBC News Online: "We believe there's an inbuilt temperature rise of 0.5-1C still to come.

Safeguarding London

"With sea level rise, there's even more of an inbuilt commitment there over the next 30 or 40 years, because the oceans take so long to warm."

Dr Mike Hulme, of the Tyndall Centre, said temperatures over the UK lowlands could exceed 40 C within 80 years.

Barbara Young, chief executive of the Environment Agency, said: "The ultimate challenge is going to be the Thames.

"We need to start planning now all along the Thames estuary if London is going to be safe for the future."

Satellite images courtesy of the Advanced Along Track Scanning Radiometer Programme