NHS resources "could be overwhelmed" by death and disease caused by major climate change over the next 50 years unless preventative action is taken now a government report warned today.

Local authorities also face huge costs to prevent "catastrophic" flooding that could cause widespread destruction and leave tens of thousands of people temporarily homeless. Billions of pounds may need to be spent on concrete flood defences while some coastal regions could even be abandoned.

The report, by the Expert Group on Climate Change and Health, is the first official assessment of the effect of global warming on health and has been launched by the government's chief medical officer, Professor Liam Donaldson.

The Health Effects of Climate Change recommends that efforts to reduce the impact of global warming should continue and an expanded research programme should be established "as a matter of urgency".

Prof Donaldson warned: "If global climate changes continue unchecked there will be an impact on the health of the population of this country."

Average temperatures in the UK are expected to rise by up to 2.3 degrees celsius, leading to hotter, drier summers and more intense heatwaves.

Heatwaves such as the one in 1976 are currently expected once in every 350 years. But by 2050, they could occur every five to six years.

This will cause a further 3,000 deaths - and 30,000 extra cases of skin cancer, unless pollution can be cut. There will also be 10,000 extra cases of food poisoning and another 2, 000 cases of cataract.

Malaria could also return to salt marsh districts, such as Essex, Kent and Norfolk, for the first time since the beginning of the last century.

The impact of the disease in the UK would be small but high-risk areas could be vulnerable to malaria for up to four months of the year.

Global warming could mean popular tourist destinations, such as Turkey, becoming increasingly tropical and vulnerable to the severest type of the disease - caused by plasmodium falciparum. Travellers could it back to the UK but it is unlikely to become established because conditions in this country are unsuitable for the species of mosquito that carries it.

Other insect-borne diseases such as the tropical west Nile fever could also be seen in the UK.

However, warmer winters should reduce deaths among the elderly by 20,000, with 2m fewer hospital admissions due to cold-related illnesses.

Prof Donaldson warned that gales and floods could cause the worst problems. The flooding of low-lying coastal areas will become more likely as sea levels rise due to the melting of the Arctic ice-cap, and storms worsen. "Flooding that spreads inland from coastal areas may be catastrophic," warns the report.

In the last 13 years, Britain has suffered three winter storms of a severity that would usually be expected once every 200 years.

The report also warns that gales could lead to more deaths and severe injuries, with people being crushed by collapsing buildings or falling trees.

Likely loss of electricity could cause further problems. The improved inspections for buildings, particularly hospitals, is recommended.

Information on the impact of climate change on public health is intended to help the government plan for long-term affects.

The report concludes that the NHS should cope well with the impact of climate change - if preventative action is taken early.

The government report comes as the inter-governmental panel on climate change prepares to finalise its third report on the global outlook next week.