By Alex Kirby  BBC News Online environment correspondent

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. 

The Thames barrier could need a redesign

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.

The southern UK: The map may need redrawing

"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

I don't see this as a change in the trend. Labour market conditions will continue to be severe

Heizo Takenaka Japanese economy minister

The fall in the jobless rate could be a first sign that the recession-hit Japanese economy is about to bounce back.

"Until December last year, the figures were completely negative," said LFSO director Masato Chino.

"Some data continue to be bad but others are so-so, showing signs of bottoming out."

Mixed views

Unusually, analysts appeared more optimistic than the government.

"When we look ahead, the economy is generally starting to enter a period of recovery," said Daiwa Institute of Research economist Tatsuya Torikoshi.

Japan's economy minister Heizo Takenaka took a more cautious view.

"I don't see this as a change in the trend. Labour market conditions will continue to be severe," he said.

Indeed, although the rate of unemployment fell last month, the actual number of unemployed people rose to 3.79 million from 3.56 million in February.

But that was mainly due to seasonal factors, said analysts.

The Japanese school year ends in March and many firms tend to push through lay-offs and cost cuts at the end of the accounting year.

Other indicators

Separate data showed that Japanese shoppers are wary about the future, as seen from a fall in both retail sales and household spending in March despite generally falling prices.

But a Reuters poll of analysts predicted that industrial production rose for the second month in a row in March.

This was in part due to rising exports fuelled by an economic recovery in the US and other countries that import Japanese goods.

Dmytro Hrodzynskyy said the concrete sarcophagus placed over the remains of the damaged reactor was failing.

Radioactive dust is escaping

Professor Dmytro Hrodzynskyy

In an interview published to coincide with the 16th anniversary of the world's worst civil nuclear disaster, the respected scientist said the remaining fuel inside the reactor was heating up.

But other experts said there was no need to worry about further explosions at the site in the Ukraine.

Professor Hrodzynskyy, who heads the Ukrainian Government's commission on radiation security, told the Izvestia newspaper that 24% of babies now born near Chernobyl have birth defects.

Thyroid cancer in local children is now 1,000 times more likely than before the disaster, he said.

Concrete poured over the ruins to seal them is cracking, Professor Hrodzynskyy says

"There is more than one kilometre [0.6 mile] of holes and cracks there," he said.

"Fuel is starting to heat up inside the ruined reactor... and radioactive dust is escaping." 

The concrete sarcophagus - designed to encase the ruins and hundreds of tonnes of nuclear fuel remaining from the 1986 disaster - was built too hastily and is now failing, the professor said.

Ukraine is dependent on Western financial aid to maintain the sarcophagus and has complained that is does not have enough to do the job properly, a BBC correspondent says.

A spokesman for the International Atomic Energy Agency in Vienna said the agency was aware of the general problems of Chernobyl but could only register official reports filed by national agencies.

There is no chance of a chain reaction inside the reactor

Volodymyr Kholosha, exclusion zone official

The head of the Chernobyl exclusion zone, Volodymyr Kholosha, said there was no reason to talk of new dangers.

"The Ukrainian and foreign experts who permanently monitor the shelter facility see no cause for concern," he said in response to Professor Hrodzynskyy's interview.

"The same has been confirmed by the data received from monitoring equipment."

He denied that fuel was heating up inside the crippled reactor.

He said the sarcophagus had been designed to allow air in and would be replaced as planned in 2007.

"There is no chance of a chain reaction inside the reactor," he said.

About 250 people gathered near the ruins on Friday to observe a minute's silence at 0123 (2223 GMT Thursday), the exact time when Chernobyl's nuclear reactor number four blew up 16 years ago.

Continuing contamination

The explosion spewed clouds of radioactive smoke that spread over much of Europe.

Between 15,000 and 30,000 have since died and the United Nations estimates that nearly six million people continue to live in contaminated areas.

A 30 km (18-mile) exclusion zone around the site is still maintained though there is some talk of trying to generate tourism opportunities in the area.

 Chernobyl's other three reactors continued to be used after the accident but the plant was closed down for good in 2000.

Eugenics is the science of using genetics ostensibly to "improve" mankind.

The idea that this was a good thing had wide currency throughout the early part of the 20th century.

The new medical technology of eugenics is going to take off

Professor Richard Lynn

Now Richard Lynn, Emeritus professor of Psychology at the University of Ulster, has written a book in which he says it is time for a re-think.

He told the BBC that advances in medical technology, such as the pre-natal diagnosis of pregnant women for genetically disordered foetuses, meant that in a sense eugenics was already being practised.

"The general principle of eugenics, that we could improve the genetic quality of the population need taking seriously.

"The new medical technology of eugenics is going to take off, because it satisfies the needs of individuals, both for themselves and as parents.

"Parents would like to have children who are free of genetic diseases, and potentially in the future they will want to have children who are intelligent.

"This is serving people's needs and wishes. As the technology comes on line to allow them to do this, people will take it up."

Prophesy of despair

Dr Tony Cole is a consultant paediatrician who works with Downs children and is a member of the Guild of Catholic Doctors.

If you are going to manipulate the genetic composition of an individual you are changing not only that individual, but perhaps a thousand descendants of that individual

Dr Tony Cole

Dr Cole stressed that the idea of genetic enhancement was specifically forbidden by current regulations.

"If you are going to manipulate the genetic composition of an individual you are changing not only that individual, but perhaps a thousand descendants of that individual.

"This is so-called germ line manipulation, and it is very tightly regulated because it could be hideously abused."

He said countries coming together to try to find an acceptable way forward.

"The fundamental issue is a question of justice between generations. Do we control the next generation in that sort of way? Are they are a sort of custom-specified commodity?"

The weak growth figure seems likely to confirm fears that the UK economy is still far from the economic recovery forecast by the chancellor in his latest Budget statement. 

Although the growth rate compares favourably with zero growth in the previous three month period, it was lower than economists were expecting. 

The consensus forecast was that the UK economy would grow by 0.4% between January and March 2002. 

Service sector slackens

The news makes it less likely that the Bank of England will raise interest rates in the next few months, despite suggestions from some economic forecasters, including the OECD club of rich nations, that rates were likely to rise soon.

Output in the service sector, which makes up the bulk of UK plc, was flat, while manufacturing output sagged. 

The service sector grew by 0.5%, unchanged from the previous three months; compared to the same period of last year services grew 2.5%. 

Growth in services was heavily dependent on High Street spending. Growth in the distribution, hotels and catering category was "a result entirely of strength in retail output," according to the Office for National Statistics (ONS). 

However, retail sales figures for March have shown a slowdown in High Street spending. 

More pain for industry

Britain's manufacturing output declined across all major sectors, the ONS said. 

"The output of the production industries is estimated to fall sharply once more," in the first quarter, according to the ONS. 

"The source of the disappointment is very much on the production side of the economy," said Simon Rubinsohn, an economist at stockbrokers Gerrard, though the service sector's performance was also below par.

"We could have expected better" from service industries, Mr Rubinsohn added. 

The British Chambers of Commerce warned that "the recovery should not be taken for granted in the next few months" and called for interest rate rises to be put on hold.

London's FTSE 100 share index, which was already having a lacklustre day, hardly flickered in response, continuing to trade about 0.3% lower on the day. 

The FTSE 100 was down 17 points at 5,180 at 0856 GMT. 

The pound dipped on the news. The UK currency was trading at 1.452 to the dollar at 0902 GMT compared with 1.454 beforehand. 

As encouraging as this number is, I am not content. We've got more to do

US President George Bush

The sharp rise in gross domestic product (GDP) fuelled hopes that the US recession which began in March last year has now come to an end.

"This number shows that we clearly have started a recovery," said AG Edwards & Sons chief economist Gary Thayer.

Cautious optimism

But although the bust might be over, there are no guarantees of a boom ahead, some analysts warned.

"The economy is probably not as strong as the headline number is suggesting," Mr Thayer cautioned.

The quarterly growth figure was the strongest since the final three months of 1999.

It followed a 1.7% expansion during the October to December period, and a 1.3% contraction in the three months to September.

But much of the strength in the US economy depends on consumers' willingness to spend.

And the weaker University of Michigan index suggests that the consumer spending spree may run out of steam.

The index for April fell to 93.0 from 95.7 in March, a steeper than expected decline.

"As encouraging as the (economic growth figure) is, I am not content. We've got more to do," said US President George Bush. Stock rundown

Analysts added that much of the GDP growth was fuelled by an increase in defence spending since US forces began military action in Afghanistan.

"It is stronger than we expected. Part of that is due to the increase in defence spending," said Wachovia senior economist Mark Vitner.

Economic activity received a further boost from a jump in new orders as firms finally exhausted stockpiled goods and raw materials. 

Growth to slow

Growth is expected to decline during the April to June period.

"In the second half of the year we are going to see somewhat slower growth," said Northern Trust chief economist Paul Kasriel.