I'm an old member of Greenpeace. I worried intensely, as I think most of my friends did, that the world was coming apart.

We worry about the seemingly ever-increasing number of natural catastrophes. Yet this is mainly a consequence of CNN - we see many more, but the number is roughly constant, and we manage to deal much better with them over time. Globally, the death rate from catastrophes has dropped about fifty-fold over the past century.

When thinking about the future, it is fashionable to be pessimistic. Yet the evidence unequivocally belies such pessimism. Over the past centuries, humanity's lot has improved dramatically - in the developed world, where it is rather obvious, but also in the developing world, where life expectancy has more than doubled in the past 100 years.

I think it's great that we have organisations like Greenpeace. In a pluralistic society, we want to have people who point out all the problems that the Earth could encounter. But we need to understand that they are not presenting a full and rounded view.

Economists treat economics as if it is a pure science divorced from the facts of life. The result of this false accountancy is a willful confusion under cover of which industry wreaks its havoc scot-free and ignores the environmental cost.

I hear so many people talking about what's wrong, whether it's climate change or whatever, but so few say, 'Well, look, we've got this problem, so let's find the solution. Let's find a scientist, let's find politicians who are prepared to shape the future, or try and keep up with it.'

Our planet is warming due to pollution from human activities. And a warming climate increases the likelihood of extreme weather.

Many business leaders are seeing the relationship between long term success and sustainability, and that's very heartening.