A United Nations report on climate change says a reduction in potentially harmful greenhouse gas emissions can be achieved, and is affordable.  But the report says that action by governments and individuals must begin immediately. Ron Corben reports from Bangkok.

The United Nations International Panel on Climate Change, IPCC, in a report released Friday, says the technology exists to curb so-called greenhouse gas emissions that are thought leading to global warming.

The report calls for the current rise in global temperatures to be halted at around two degrees Celsius above pre-industrial age levels.  It says this can be achieved by 2030 at a cost to the global economy of about three percent of worldwide gross domestic product.

Rajendra Pachauri, chairman of the IPCC, says the report emphasizes the need for action by both individuals and governments.

"An extremely powerful message in this report is the need for human society as a whole to start looking at changes in lifestyle and consumption patterns," he said.

The U.N. panel says greenhouse gas emissions (GHG) rose 70 percent between 1970 and 2004, with most coming from the energy sector.  Ogunlade Davidson, the panel's co-chairman, says existing policies will not halt GHG growth.

"If we continue to do what we are doing now, we're in deep trouble," he explained.  "As it's clearly stated here, with the current climate change mitigation policies, global GHG emissions will continue to grow over the next few decades.  That is one immediate message from us to take home."

The report says stabilizing emissions of carbon dioxide, the chief culprit in global warming, can be done through increased fuel efficiencies, improved building codes, the setting of stricter industry standards, plus financial incentives.  For the first time, the IPCC endorses the option of nuclear power.

The report will be forwarded to governments, and will enter the public debate over how best to combat climate change. Hans Verolme, director of the World Wildlife Fund's global climate change program, says the matter is now up to the politicians.

"My message to the politicians, to which this document is addressed, let's get to work," he said.  "Politicians need to get together and recognize there's an enormous potential for increasing energy efficiency."

The next step will come when leaders of the major industrialized countries meet in June, followed by another United Nations conference on climate change in Indonesia in December.