Jon Snow: Let's go to David Hempleman-Adams, because you think we're letting the viewer down anyway.

David Hempleman-Adams (explorer): I don't think we've seen enough about global warming, from my own experience. I went up to the Arctic in 1980 and then I went up again last year - and, in that time, there is one-third less pack ice. I was going over the Brazilian rain forest back in the early 1980s, went flying over it again last year, and there's an area the size of France that we've cut down. So we are seeing huge devastation in a really small amount of time, 20 years.

Jon Snow: I think you'd accept that there has been, not a huge amount, but a fair amount of coverage of both Antarctic and Arctic ice melt. The problem, surely, is what do we do after that? I know from my own experience that there's only a limited amount of large chunks of ice falling into water, polar bears swimming, even your good self dragging a sledge - there's only a limit to how much of that you can keep putting on the air, because it all looks the same as the last time we saw it. We then have to push on somehow, to try to link what you're experiencing in the Arctic to what we are doing in our kitchens or in our cars or whatever else to bring that about. That's a big challenge, isn't it?

David Hempleman-Adams: I absolutely agree. And when you were talking about Katrina, all the stories were about the human suffering and not actually about the weather or what caused it. You can talk to different meteorologists and they can say: “We're coming up to an ice age or we're going into this cycle of ice ages.” But all the meteorologists I talked to, all the experts, they all believe that in this really short time, 20 years, we've devastated the climate. It shouldn't be happening that fast. So we have to try and link, somehow, these tornadoes, Katrina and anything else that's going to come up in the next five years, and try and relate that to global warming.

Jon Snow: Elizabeth Palmer, it feels dangerously close to a news story.

Elizabeth Palmer: I think that, for the American channels, for it to get the coverage it deserves it has to pass the "so what?" test.

Jon Snow: You mean: "So what? Your grandchildren are going to be dead."

Elizabeth Palmer: People need to know what to do about it. As you pointed out, sitting in our kitchens and living rooms, it's all very well to be told that cataclysmic things are happening, but in order for it to begin to make a difference, it has to become a political story and a prescriptive story. There have to be people with some gravitas saying: “We've gotta do this.” And if the government doesn't want to, then let us now cover the fight. Just as a story of enormous, apocalyptic change, it should concern us. I don't think it does.

Jon Snow: Charlie Kronick, it's got no "so what?" factor.

Charlie Kronick: Bizarrely, I think that's true. And even more bizarrely, I almost agree with Bjorn Lomborg. But the problem with climate change is that it has been expressed as an environmental issue, which means that it can be put off in the environmental ghetto. What Katrina taught us very clearly is that it's vulnerable communities that pay the price. Now, vulnerable communities in Africa, in Latin America, in South Asia, have been paying the price. This is the first time that a vulnerable community in the centre of the media world, in North America, has been at the centre of this. When climate change will become a news item that you can't escape is when the realisation increases that you can't separate it from issues of poverty, issues of global trade or issues of health. And even, bizarrely, if you look at the oil price, it skyrocketed after Katrina because of the impact on the oil infrastructure. It's not just getting dangerously close to a real news story, it's getting dangerously close to real politics.

Jon Snow: You're letting people down, Elizabeth. He said it.

Elizabeth Palmer: It's a story that is multifaceted. I have confidence that it's going to come up and it's going to be part of the daily dialogue of news. I don't know when that will happen, but I can tell you that it has already come up in Canada, for example, as a defence-policy story, because all of a sudden Canada has an Arctic it is not at all equipped to defend. So it's going to creep onto screens in disguise.

Jon Snow: Andrew, do you divine these signs, that it will suddenly become the daily staple?

Andrew Tyndall : I would press this argument even further and say that it's actually better not to cover global warming as a story. It's better to cover it as an angle of all the other stories. The word to newsrooms would be: Don't try and lobby for an increased environmental beat, so we can do more features, sending the person up to the Arctic, because you'll get that on once every couple of months and it'll be down at the bottom of the news program on a light news day and it won't be, when there are the big headlines. The lesson from the tsunami was that it's coastal populations who are vulnerable. I say what you do is make it the third bullet point of your story on oil prices, on transportation, on hurricanes, on anything to do with coastal residents. That's the way you get global warming covered, not as a story itself.

George Monbiot: I'm suspicious of that approach for two reasons. The first is that that was exactly what the BBC said it was going to do in 1992. It said: “Don't worry about the fact that we're not doing dedicated environmental coverage; we're going to embed the environmental coverage in everything else.” They totally failed to do so, and effectively let themselves off the hook by making that promise.

The second reason is that unless an issue divides the major parties, it's very hard to make that issue news unless you're intending to make it news. One of the problems we have in almost all developed economies is that the major parties don't really want to do very much about it. They will stand up and say, “Yes, it's very worrying and something should be done.” But in both the United States and in the United Kingdom, there is an agreement - even in the U.S. now - that something should be done about it, but very little determination on the part of either party to push that. And that leaves news journalists with a problem, because if they're trying to make climate change part of their everyday coverage, the political parties aren't giving them that opening.

Jon Snow: Maybe we shouldn't even leave it to politics. Fran Unsworth, here's an example. I was watching the telly yesterday and what was on it? Stella McCartney's new fashion release to H&M stores in London, and people flocking in to get this stuff. It was an absolutely nonsensical report, in which I didn't think the stuff even looked very nice and the people looked decidedly unhappy buying it, but they cleared the shelves and that was that. Now, let us imagine that we send someone along with some brief to reflect the global-warming aspect of Stella McCartney's set of clothes arriving on the shelves in Oxford Street. One: Air miles to get the clothes from Taiwan, China, wherever, to the shelves. What was the cost in ozone demolition to get this stuff there speedily - had to come by air because it was a quick new release of fashion, so didn't come by sea. Can you imagine a BBC newscast that, as a natural matter of course, reflects that the new Ford Fiesta has an environmentally destructive level of 0.89 per cent - or whatever.

Fran Unsworth: I can, actually, to be quite honest. I think it would be an interesting approach, which I can easily see on Newsnight, and I think that we do that kind of thing quite often. George said we bottled out of environmental coverage since 1992. I just can't see that. We have five environment correspondents who are working alone for network news, and we have another 11 or so who are working in the English regions. So I don't think we can be accused of not committing ourselves to environmental coverage.

Your point is a good one, about how many polar-bear pieces you can end up seeing on the screen. The way to approach it is the way that we have been approaching it, which is to kick it into the realm of other specialisms. We get our economics correspondents to look at what the impact of development in India and China is going to be on the environment. Rupert Wingfield-Hayes, our China correspondent, did a piece about how the Chinese are hoping to cope with an increase in energy needs by developing clean-coal power stations. This is the multifaceted approach that you were talking about, which frankly I think the BBC are already doing.