Global warming is often in the news these days, usually in connection with changing, and sometimes destructive, weather patterns. But the World Health Organization says rising temperatures also have alarming implications for public health. VOA's Kurt Achin reports from Jeju, South Korea, where delegates to a WHO gathering say they will focus more on the issue in the years ahead.

Dr. Timothy Pyakalyia says farmers in his tropical homeland, Papua New Guinea, have been enjoying fruit harvests at elevations where fruit never grew before.

Along with that good news, Dr. Pyakalyia - who is also PNG's Deputy Secretary of Health - says there is some bad news.

"We're seeing local malaria transmission in zones we've never seen before," he said.

Dr. Pyakalyia spent the past week here in Jeju with dozens of other Western Pacific delegates to the World Health Organization. WHO Spokesman Peter Cordingly says the new malaria cases can be traced to global warming.

"The warm zones are spreading in this region into areas that weren't warm before. And when that happens, you're looking at vector-borne diseases, mosquito-borne diseases... Dengue and malaria are just becoming very, very difficult to control," he said. "The numbers are growing, and that's because the numbers of mosquitoes are growing, as well."

Cambodian women with their children, many of whom are sick with dengue fever, wait for treatment outside a children's hospital in the capital Phnom Penh, Cambodia, 27 Jul 2007

Mosquitoes thrive in warm, wet conditions. WHO officials say they have seen dramatically higher incidences of mosquito-borne disease in Singapore, Cambodia, and other countries.

The WHO's Western Pacific regional director, Dr. Shigeru Omi, says global warming is emerging as one of the organization's most urgent issues.

"Already we have evidence to indicate that global warming [and] climate change have a negative impact on health," he said. "So the WHO, I think, has to play our role."

WHO officials say larger mosquito populations are just one of global warming's health threats. Higher temperatures will dry up arable land in some Pacific countries, many of which are already poor and experiencing widespread malnutrition. Changing weather patterns may also put densely populated areas at risk of deadly flooding, along with the resulting contamination of food and water supplies.

Right now, the WHO is not explicitly raising the issue of global warming in its public activities, but spokesman Cordingly says that is about to change.

"Next year, global warming will show up on our agenda," he said. "By then we will have done quite a lot of research into the subject."

Officials say that research will probably be put to use in new programs urging governments to cut back on fossil fuel consumption and stop destroying the region's rainforests - which are believed to be two of the biggest factors in climate change.