As Development Secretary, I have seen in the developing world that climate change there is not a theory, is not a future threat: it is a contemporary crisis.
As times change, so do the way each generation see the world. It is rather like the way our generation came to see our grandparents' views on the Empire and colonies as outdated.
David Cameron can change the branding of the party, but he can't change the beliefs.
As Scots, we certainly want change today, but the change the Nationalists offer is not the change we want or need.
I'm at one with Ed Miliband in saying that it's important that people have the right to express their democratic voices and also their deep concerns about climate change because we have a planet in peril.
Just as people have long believed that strengthening ties of trade improves the prospects for peace and the free exchange of ideas, Facebook friendships or Twitter followings already transcend national borders.