Well, Margaret Thatcher was one of the first world leaders to warn about the problem of climate change. Thatcher trained as a chemist. She understood you can’t change the chemical composition of the atmosphere without consequences.

In a speech to the United Nations in 1989 she said, "What we are now doing to the world by adding greenhouse gases to the air at an unprecedented rate is new in the experience of the earth. It is mankind and his activities that are changing the environment of our planet in damaging and dangerous ways."

Thatcher was right. In 2013 New Zealand was hit by our worst storm in sixty years. It left 30,000 Wellington homes without power, some for up to a week. It set the city back $4 million in direct clean-up costs. Around the country, it resulted in over $31 million worth of insurance claims.

That summer of the same year we had our worst drought in seventy years. It cost New Zealand $498 million in lost exports. Treasury estimates that this drought cost our economy over $1.5 billion.

The worst drought in seventy years. The worst storm in sixty. The warmest winter on record. Billions of dollars in costs and damages. All in the same six months.