Around 150,000 deaths now occur in low-income countries each year due to climate change that causes crop failure and malnutrition, diarrhoea, malaria and flooding, says the World Health Organisation (WHO).

"Almost 85 percent of these excess deaths are among young children," WHO spokesperson Sari Setiogi said.

Health hazards from climate change are diverse, global and difficult to reverse over human time scales, WHO experts said at the Climate Change: Global Risks, Challenges and Decisions conference last week in Copenhagen, according to Setiogi.

"They range from increased risks of extreme weather events, to effects on infectious disease dynamics and sea level rise leading to salinisation of land and water sources."

The experts also pointed out that the health impacts of climate change are felt unequally.

"Whether it’s the 70,000 excess deaths from the heat wave in Europe in 2003, or new malarial deaths in the central African highlands, the people at greatest risk for climate-related health disorders and premature deaths are the poor, the geographically vulnerable, the very young, women and the elderly," Setiogi said.

"The populations considered to be at greatest risk are those living in small island developing states, mountainous regions, water-stressed areas, megacities and coastal areas in developing countries, particularly the large urban agglomerations in delta regions in Asia, and also poor people and those lacking access to health services."

On the brighter side, improvements in environmental conditions could reduce the global disease burden by more than 25 percent, the experts said.

A large part of the current burden is linked to energy consumption and transport systems. Changing these systems to reduce climate change would have the added benefit of addressing some major public health issues, Setiogi said.

These include outdoor air pollution (800,000 annual global deaths); traffic accidents (1.2 million annual deaths); physical inactivity (1.9 million deaths); and indoor air pollution (1.5 million annual deaths), she added.

The spokesperson said putting these three health arguments at the centre of discussions at the climate change summit scheduled in Denmark this December "would ensure that in the new post-Kyoto agreement we will all share in the health and economic benefits that can accrue from countering climate change."