This former United Kingdom prime minister was already conscious of the reality and global threat of climate change in 1989. With her speech to the UN in November 1989, Thatcher became the first prominent political leader to warn the world about the danger of climate change, and to outline a strategy for dealing with it. She brought up the threat from greenhouse gases and the “large hole” in the ozone layer. Some say that in the last 60 years, she has done more than anyone else to put environmental issues on the national and international agenda.