Wellington - The Royal Society of New Zealand, whose members are the country's most eminent scientists, moved Thursday to settle the debate over global warming with a statement declaring unequivocally that humans are to blame.

"The globe is warming because of increasing greenhouse gas emissions," the society said, reporting the findings of an expert committee on climate.

"Measurements show that greenhouse gas concentrations in the atmosphere are well above levels seen for many thousands of years. Further global climate changes are predicted, with impacts expected to become more costly as time progresses.

"Reducing future impacts of climate change will require substantial reductions of greenhouse gas emissions."

The society said it was speaking out because of the controversy over climate change and its causes and confusion among the public.

It said that major international policy changes would be required to deliver reductions in greenhouse gas emissions but various technologies existed to provide them.

The society said these included more efficient use of energy - for example, better designed and insulated houses, more efficient appliances and industrial processes.

It also advocated renewable energy sources, including hydropower, geothermal, wind, marine, and solar power, use of lower-carbon fossil fuels, such as natural gas, and capturing and storing emissions from power plants.

The society said more efficient transport and urban systems and the use of appropriate biofuels and other renewable energy sources to power transport were also needed along with reforestation, reduced deforestation and lower emissions from agriculture, which account for nearly half of New Zealand's total greenhouse gases.

The Green Party welcomed what it called "the unambiguous statement" by the Royal Society, with co-leader Russel Norman saying, "The New Zealand public is frustrated that progress on addressing climate change has been hampered by myths parading as science, when the consensus among climate scientists has been remarkably clear."

He said the statement provided welcome reassurance to the public in the face of lobby groups with vested interests and anti-environmental agendas which continued to try to spread scepticism. (dpa)