Climate change is for real. We have just a small window of opportunity and it is closing rather rapidly. There is not a moment to lose.

Unless a price can be put on carbon emissions that is high enough to force power companies and manufacturers to reduce their fossil-fuel use, there seems to be little chance of avoiding hugely damaging temperature increases

Climate change: It's here. If we don't react, war, pestilence and famine will follow close behind

There is, even today, a Flat Earth Society that meets every year to say the Earth is flat. The science about climate change is very clear. There really is no room for doubt at this point.

We have embarked globally on a path of unsustainable development. Our lifestyles, the way we produce goods and services, are all part of a system that is completely unsustainable. I see solutions to climate change leading to a much larger philosophical shift in the way human society develops. We need a new matrix to define what human progress is.

The impact of climate change will fall disproportionately upon developing countries and the poor persons within all countries. It will therefore exacerbate inequalities in health status and access to adequate food, clean water and other resources.