Within the next quarter century, AIDS is projected to be among the top three causes of death around the world.  That dire prediction comes from researchers at the World Health Organization.  More dire predictions come from climatologists, who say there's new evidence of the impact of rising global temperatures.  VOA's Melinda Smith and Paul Sisco look at the top medical and science developments of 2006.  Melinda Smith narrates.

In late 2006, an epidemiologist said, ?It will be increasingly hard to sustain treatment programs unless we can turn off the tap of new HIV infections.?  Twenty-five million people have died of AIDS.

Another 39 million are still living with HIV or AIDS.  Health officials continued to preach the practice of safe sex ...such as the use of condoms.  Clinical trials in which circumcision was performed on a group of adult heterosexual men showed great promise in reducing the risk of AIDS.

In 2006 the World Health Organization reversed itself and approved the use of DDT to spray indoors for the mosquito parasite that causes malaria.   DDT has been banned for agricultural use for 30 years because of possible links to cancer.  However world health officials believe this version of the insecticide is not harmful to humans.

There was growing concern in 2006 about the spread of avian flu to humans, and in particular, fears the H5N1 virus could stimulate a human-to-human influenza pandemic. Scientists are working to develop a vaccine.

Towards year's end United Nations health officials called for the wide distribution of a new affordable vaccine against the human papilloma virus. HPV causes 70 percent of cervical cancers.  Cervical cancer is the second most common type of cancer among women.

Obesity became a global issue.  Blame was placed on a sedentary lifestyle and foods high in fat and sugar. On the other hand, not eating enough appeared to be the latest trend among fashion models.  Whoever said you can never be too thin had it wrong, in the minds of health officials in Spain.  They called for the world's first ban on overly-skinny models from the fashion runway.

On the medical research front, stem cells were in the news this year.  President Bush vetoed federal funds for research in the United States.  In South Korea, some highly-touted successes were proven false.  Nevertheless, research continues worldwide, and stem cell therapies are showing promise in battling a number of neurological diseases.

In 2006, dramatic signs of global warming earned international attention.  Findings that both the north and south poles are melting surprised researchers.  A long-term study revealed that Greenland had lost 100 billion metric tons of ice between 2003 and 2005.

Some scientists say a hotter planet could be to blame for such natural disasters as the year's wildfires in the western United States, and growing drought conditions in Africa, and  typhoons caused mudslides in China and the Philippines which claimed thousands of lives.

Record high oil prices helped make renewable sources - such as wind and solar power - the fastest growing energy sector in the United States. Meanwhile. Chevron announced the discovery of up to 15 billion barrels of oil more than two kilometers beneath the Gulf of Mexico.

Discovery of another kind from the distant past. In February, a 3,000-year-old tomb was found in Egypt's Valley of the Kings. In September, scientists also announced they had found the skeleton of a 3-million-year-old early human ancestor.

Back to the future... NASA returned to space in 2006 with three crucial shuttle missions to the expanding International Space Station. Planetary probes, scrutinizing Mars, found signs of recently flowing water.  Another probe gave us incredible images of Saturn and its rings. 

In August, a conference of astronomers stripped Pluto of its status as a planet, but NASA is still sending a probe to Pluto.  It arrives in 2015.

Finally, the U.S. space agency also began a countdown of another sort, revealing its design for the next generation space shuttle craft and announcing plans for a multinational, permanently-manned base on the moon by 2020.