The newly elected president of the World Conservation Union (IUCN) said Wednesday that global warming and the lack of protected marine zones were key challenges that needed to be hoisted high on the green agenda.

"Global warming is the single biggest environmental problem this world faces," Valli Moosa, a former South African environment minister and anti-apartheid activist, told Reuters.

He was picked as president for a four-year term Wednesday at the IUCN's third World Conservation Congress in Bangkok.

"Another big challenge we face is to declare protected areas in the oceans and the high seas. Twelve percent of the land surface is under conservation but only 1 percent of the ocean," Moosa said in a telephone interview from the Thai capital.

"This is an area that will need concerted attention and will be quite a high priority for us."

Among its members, the Swiss-based IUCN counts 81 countries, 730 national non-governmental organizations (NGOs) and 77 international NGOs. Its total external operating income in 2003 was just over 102 million Swiss francs ($87.70 million).

Over 10,000 scientists work on its six commissions and its data bases, assessments and case studies are among the world's most respected and frequently cited sources of information and reference on environmental issues.

"This is a potentially powerful organization ... The union is well positioned to take conservation to a completely new level," Moosa said.

"We do not want conservation to just remain the activity of specialized environmentalists or groups of concerned citizens. We plan to put it higher up on the agenda of groups like the United Nations and the WTO (World Trade Organization)," he said.

Moosa also said he was keen to raise the organization's state membership. Oil-rich Angola and Iran are the latest countries to join -- two states which have more than their fair share of environmental problems.

"We will also be making a bigger push on the role of conservation in economic life and strive for greater interaction with businesses and global corporates," he said.

He said that a positive sign was the growing number of sustainable indices which allowed investors to scrutinize the environmental records of publicly listed companies.