My advice is very simple: if you can win a small battle, it gives you confidence in the political process to take on bigger battles, and so it is very much a bottom-up grass-roots way of doing politics.

Thirty years ago, if you said the country was living beyond its means, people would have thought about economics. Now, if you talk about the country, or the planet living beyond its means, you think about the environment. We are taking out more than we are giving back. We are consuming energy, water, and other natural resources in a way that is leading to huge and often irreversible damage to the planet. So too are most other developed nations. And so too will China and India if they follow the same path of economic development as us

First, climate change is the greatest long-term threat faced by humanity. It could cause more human and financial suffering than the two world wars and the great depression put together. All countries will be affected, but the poorest countries will be hit hardest. Secondly, the costs of inaction far outweigh the costs of action.

If you decide to run for the leadership, you have to go through it with the people you love. But you also have to protect them and I am determined to protect my mum.

What's now urgently needed [to stop environmental disaster] is the international political commitment to take action to avoid dangerous climate change.

In the end, human history is made up of all our decisions.

Today, the UK must be the pioneer of a new model of economic change, that integrates social and environmental consideration. This is not just a question of values and moral duty. It is about our economy's capacity to sustain itself