United Nations AFP-JIJI

U.N. Secretary General Ban Ki Moon has lauded a little-remembered act in Margaret Thatcher's welter of political firsts — when she urged action on global warming.

Ban "pays tribute to her contribution to addressing climate change, having been one of the first world leaders to issue a warning about its effects by calling for action at the U.N. General Assembly already in 1989," his spokesman said Monday.

Thatcher, who died the same day at age 87, gave a speech to the United Nations in 1989 that many environmentalists say helped bring the climate crisis into the mainstream. She later came to distance herself from her plea as the cause was increasingly taken up by leftwing parties.

The ex-prime minister told fellow world leaders in New York that green- house gases had become an "insidious danger."

"What we are now doing to the world, by degrading the land surfaces, by polluting the waters and by adding greenhouse gases to the air at an unprecedented rate — all this is new in the experience of the Earth," she said. "It is mankind and his activities which are changing the environment of our planet in damaging and dangerous ways," Thatcher warned.

She later changed her mind, and in her 2002 book "Statecraft" called climate change warnings "alarmist" and an excuse for "worldwide, supranational socialism."

The U.N. chief told reporters that "we will miss her great leadership. She was a pioneering leader for her contribution to peace and security, particularly at the height of the Cold War."

"She was also a great model as the first woman prime minister of the United Kingdom, who not only demonstrated her leadership but has given such great hope for many women for equality, gender equality in Parliament," Ban added at The Hague.