20130927_BB

Source: BBC TV News

URL: N/A

Date: 27/09/2013

Event: Walport: "climate warming is really a bit of a misnomer, it's actually climate disruption"

Attribution: BBC TV News

People:

  • Dr. Tamsin Edwards: Climate scientist and blogger
  • Jenny Hill: BBC reporter and crime correspondent
  • Louise Minchin: BBC journalist and presenter
  • Rebecca Morelle: BBC science reporter
  • Dr Rajendra Pachauri: Chairman of the IPCC
  • Charlie Stayt: BBC journalist and presenter
    • Sir Mark Walport: Chief Scientific Advisor, UK Government

Charlie Stayt: Good morning. First, our main story. The world's top climate change scientists are to give their strongest warning yet that humans are causing global warming. In its first report for six years, the Intergovernmental Panel on Climate Change will say it's virtually certain that pollution is at least partly responsible for rising temperatures.

Louise Minchin: The past 15 years have seen a slowdown in warming, but researchers say this is due to natural variation. They'll point to large-scale changes in the ocean and warn of rising sea levels and shrinking ice sheets and glaciers.

Rebecca Morelle: Over the last 100 years, temperatures have been on the rise. The planet's changed in ways that we've never seen before. And today scientists are expected to say they're more certain than ever that humans are partly to blame. The IPCC report is the most comprehensive assessment of climate change, to date. It's taken years to put together and involved more than 800 scientists. They're likely to warn that temperatures could rise between 1.5 and 4.5 degrees Centigrade - anything above 2 is considered dangerous. In the worst case, sea levels could climb by nearly a metre, and the Arctic could have ice-free summers by 2050.

Rajendra Pachauri: Well, the glaciers, as this report will bring out - they are melting all over the world. And, you know, that's something which you really cannot ignore. It's an important finding in this report.

Rebecca Morelle: But central to the report will be the global warming "pause" - the fact that since 1998 temperature rises have slowed. The IPCC will have to explain why it failed to predict this, while insisting that the warming planet remains a global threat. Rebecca Morelle, BBC News, Stockholm.

Charlie Stayt: Yes, we'll be speaking to the government's Chief Scientific Advisor in a few minutes' time - that's coming up at about 10 past 7.

* * *

Charlie Stayt: Now, in a major report today, scientists will say they're more certain than ever that pollution is responsible for the planet warming up.

Louise Minchin: But they'll also say that the rising temperatures may be temporarily paused, and admit that they got things wrong, on global warming, in the past. So, what's going on? Here's Breakfast's Jenny Hill to talk us through it. A very good morning, Jenny.

Jenny Hill: Good morning. We all know the world is warming up. Today a major report will explain the science behind that. It's taken six years, more than 800 experts and some 9,000 studies. What's baffling scientists is the rate at which global warming has slowed down over the last 15 years. Take a look at this graph - you can see temperatures gradually rising but then here - in the late '90s - they pause. Now there are several theories as to why. Industrial pollution may be reflecting the sun's rays, or perhaps more heat is being stored in our oceans. It's no wonder, perhaps, there's still some confusion and scepticism - and some question the science behind this report. What the climate change experts are, though, expected to agree on, today, is this: they're more certain than ever before that human beings are at least partly responsible.

Louise Minchin: Jenny, thank you very much for going through it a bit for us.

Charlie Stayt: Let's talk more about this with climate scientist and blogger Tamsin Edwards, and in London is Sir Mark Walport, the government's Chief Scientific Advisor, who is tasked with making sure politicians take the science seriously. A very good morning to you both. Sir Mark, if I could start with you, what is the message that you're sending out, as you reflect upon these findings?

Sir Mark Walport: The important message is that the certainty that humans are contributing to climate change is greater than it's ever been. And there's really two key numbers. The first number is that we are putting into the planet - into the atmosphere, each year, 10 gigatonnes of carbon. That's 10 billion tonnes, 10,000 million tonnes of carbon, each year. And that's been associated with an increase in temperature, on average, of between 0.8 and 0.9 degrees Centigrade since the start of the last century. And the real story is that actually this is continuing - the oceans are continuing to rise by about three millimetres each year. And the real story is that actually we can't continue, in the long term, to put in carbon emissions at the rate we're currently doing.

Louise Minchin: So that's the message you're trying to get across to government ministers.

Sir Mark Walport: Yes.

Louise Minchin: What about the "pause"? Because people who are sceptical use that as evidence against what you're saying, really, don't they.

Sir Mark Walport: I know, but I think that the issue is that climate is extremely complicated and there's a lot of natural variation. So, of course there's variation each year with the seasons, and there are 10-year cycles, there are shorter-term cycles. The oceans are an enormous heat sink, and over periods of years, which can be 10 years or more, then there are variations, there are natural pauses and then it goes up again. But the trend is an inexorable trend, and it's not something that we can ignore.

Charlie Stayt: Dr. Tamsin, could you give us your reflections, firstly on that pause - people are talking about the pause - this the flatlining - 1998 to the present day, things haven't got warmer.

Tamsin Edwards: Yeah, I think I'd like to slightly take issue with the word - you know, scientists are "baffled", I don't think we're baffled. I think the important thing to ask about the pause is - is, um, you know - of what, and why. So it's actually a pause in the temperature of the atmosphere, right. And the atmosphere isn't the only part of the planet, we've got to think, as Mark said, about the ocean. And so, although we're seeing this pause of about 15 years in the atmosphere, we think one of the important reasons for that is because that heat is moving around. And we heard a little bit about some of the other reasons, that the sun's output is a little bit weaker - actually, one thing there was wrong. We think probably the volcanoes there are erupting in the tropics are a little bit more important than the industrial pollution.

Charlie Stayt: Because, literally, they're putting - what, dust into the atmosphere, which is - which is stopping the sun's -

Tamsin Edwards: Sort of, yeah. So, both when you get volcanic eruptions and also when you burn coal, you emit this gas sulphur dioxide. And that reacts with water in the atmosphere, and it gives you little particles that reflect the sun. So we - we're not baffled, you know, we have a good understanding of these kind of different things going on. I think the most important thing is that climate is long-term, it's 30 years or more, and these 15 years - you know, that's not climate, that's just sort of a little bit of the picture. We need to look at the big picture.

Charlie Stayt: Sir Mark, how conscious are you of the sceptical argument? Those who are listening to what you're saying and looking around them, and concerned that they don't see these things marrying up. You'll be aware of that mindset, and in a way, what has to be done to try and get this message through in a way that people can understand.

Sir Mark Walport: Oh well I think this is absolutely right, it is about very clear communication. And let's be absolutely clear - this isn't a matter, at the end of the day, that people can vote about. There is actually a right answer, as to whether humans are contributing to global warming, and that answer is that we are. And I think the other very important message to get across is that a 0.9 degree Centigrade rise, over about 100 years, doesn't seem like a lot. But the issue is that that isn't evenly distributed. And climate warming is really a bit of a misnomer, it's actually climate disruption, and we're beginning to see the effects of that. So, for example, the floods in the UK in 2000, the heatwave in 2003, the heatwave in the United States in 2012. Climate scientists are increasingly clear that there's evidence that there is human contribution to these events. So it's the extremes we have to worry about.

Louise Minchin: And Tamsin, just briefly, you know, we are an adaptable species, that's kind of why we've survived so long. So, what are the chances of us being able to adapt to what's going to happen, actually?

Tamsin Edwards: I mean, that's not really my area, but I'd like to quickly talk about the scepticism, because I spend quite a lot of time talking to sceptics and I try to understand, kind of, what their concerns are, you know, where the questions are, in the science. And I think we're trying to find a better way of doing this, rather than having a big, polarised kind of name-calling shouting match about "We are completely right" and, you know, "We think you're completely wrong". It's important to just try to pick apart the strengths and the weaknesses. They ask us some good questions that we can reply to. And I think that's part of the process. The IPCC has been very open to having reviewers from those sceptics, so I think we're getting much better at, sort of, bringing the scientists and the sceptics together, working out what we agree on and why. And not having these kind of extreme camps, basically.

Charlie Stayt: Very interesting, thank you both for your time, this morning.

Louise Minchin: Thank you very much, thank you.