A top Russian scientist has warned that the earth will experience 'global cooling' in next 50 years, followed by a period of global warming in the early 22nd century.

"On the basis of our solar emission research, we have developed a scenario of global cooling of the earth's climate by the middle of this century and the beginning of a regular 200-year-long cycle of global warming at the start of the 22^nd century," said Dr Habibullo Abdusamatov, the head of the space research sector of the Russian Academy of Sciences' astronomical observatory.

Abdusamatov said he and his colleagues had concluded that a period of global cooling similar to one seen in the late 17th century - when canals froze in the Netherlands and people had to leave their dwellings in Greenland - could start in 2012-2015 and reach its peak in 2055-2060.

Environmentalists and scientists today focus on the dangers of global warming provoked by man's detrimental effect on the planet's climate, but global cooling - though never widely supported - is a theory postulating an overwhelming cooling of the Earth which could involve glaciations.

Abdusamatov said such climate change will have serious consequences and that authorities should start preparing for them because "climate cooling is connected with changing temperatures, especially for northern countries."

"The Kyoto initiatives to save the planet from the greenhouse effect should be put off until better times," he was quoted as saying by RIA Novosti.

He said that the global temperature maximum has been reached on the Earth and it will decline to a climatic minimum even without the Kyoto protocol on cutting greenhouse gas emissions.