Thorne says: Just remember, Greenland was named so about 1000 years ago, when it was green. Was humanity responsible for that bit of warming?

Was that a slip? Greenland got colder after its original discovery.

Anyway, I looked it up and it seems most likely that it was called Greenland by Erik the Red or some other Norse character to make other settlers think it was a pleasant place to live, rather than because it really was green and lush, although it might have been in a very few places in the extreme south: this was during the Mediaeval Warm Period, as I'm sure you are aware. (I didn't know that myself, however, and was just making a play on the country's name to emphasise my own arguments.)

I have already conceded the point regarding whose fault global warming is. I don't necessarily blame mankind for it now. But that's not my argument now.

Wolfscout: It would be utterly selfish and grossly inhumane to sit back and do nothing to avert the worst consequences of global warming if it is within our power to mitigate it. On an individual level we should do all we can to minimise our own effect on the planet - to reduce our carbon footprint as it is quaintly called. And on a global level, we should be taking steps now to protect those at greatest risk by helping build flood defences, reclaiming land and, where necessary, relocating whole communities.

We're not defeatists, are we? I'm sure we can find a way if we want to. See below.

Ozme: Good point about the hole in the ozone layer. The hole fluctuates in size according to the season. In 2006, the hole over Antarctica was the biggest ever due to tropospheric ozone depletion (am I convincing you that I know what I'm talking about?). The stratospheric ozone layer - which does more to protect us from the sun's radiation than it affects global warming - is/was slowly diminishing, by about 4% every decade.

It was thought that the reduction of ozone was due to the emission of CFC's at ground level. I wouldn't dare to suggest who or what was emitting them, or how long for, but as soon as international resolutions to replace CFC's with something not quite as bad (HFC's) were implemented due to the Montreal Protocal (yay Canada!) in 1987 things started getting better, or at least, stopped getting worse.

This demonstrates mankind's ability to influence natural events.

However, the hole over Antarctica is still there and, provided global warming doesn't slow its repair, it will remain until somewhere around 2024, while the hole over the Arctic is likely to be there much longer: possibly until 2075. So make sure you're using factor 40+ sun lotion for quite a while yet.

TYWD