Source: BBC Radio 4: Today Programme
URL: N/A
Date: 13/02/2014
Event: Sir Brian Hoskins on the missing heat: "Oh yes, it's there in the oceans"
Credit: BBC Radio 4
People:
Justin Webb: Is there a link, Sir Brian, between the rain that we have seen falling, in recent days, and global warming?
Brian Hoskins: There's no simple link - we can't say "Yes" or "No, this is climate change". However, there's a number of reasons to think that such events are now more likely. And one of those is that a warmer atmosphere that we have can contain more water vapour, and so a storm can wring that water vapour out of the atmosphere. And we're seeing more heavy rainfall events around the world, and certainly we've seen those, here.
Justin Webb: So it's the heavy rainfall, it's the severity of the event, that points us in this direction?
Brian Hoskins: Well, in this event, we've had severe rainfall but we've also had persistence, and that's where I say: we just don't know whether the persistence of this event is due to climate change or not. But another aspect is sea-level rise, that the sea level has risen about 20 centimetres, over the 20th century, and is continuing to rise, as the system warms, and that of course makes damage in the coastal region that much greater, when we get some event there.
Justin Webb: But can a reasonable person, possessed of the evidence, as it is known to us at the moment, say "Look at the rain that we've had recently", and say "Look, I do not believe that the evidence exists, that links that rain to global warming"?
Brian Hoskins: I think the reasonable person should look at this event, they should look at extremes around the world, the general rise in temperature that's well recorded, reduction in Arctic sea ice, the rise in sea level, a number of extreme rainfall events around the world, the number of extreme events that we've had - we've had persistent droughts, we've had floods and we've had cold spells and very warm spells. The number of records being broken is just that much greater.
Justin Webb: Lord Lawson, it's joining the dots, isn't it?
Nigel Lawson: Now I think that Sir Brian is right on a number of points. He's right, first of all, that nobody knows. Certainly it is not the case, of course, that this rainfall is due to global warming, the question is whether it is marginally - global warming has marginally exacerbated it. He's right, and nobody knows that. Though, he's right, too, to say that you have to look at the global picture. And, contrary to what he may have implied, in fact, people who have done studies show that there has been no - globally, there has been no increase in extreme weather events. For example, tropical storms, which are perhaps the most dramatic form of weather events - there's been, in the past year, there has been an unusually quiet year for tropical storms. And again, going back to the "nobody knows", only a couple of months ago the Met Office were forecasting that this would be an unusually dry winter. So -
Justin Webb: Do you accept that, Sir Brian? Just on that point, that important point about the global picture. Do you accept, Sir Brian, we haven't actually seen the kind of extreme conditions that we might have expected?
Brian Hoskins: I think we have seen these heavy rainfall events around the world. We've seen a number of places breaking records - Australia, with the temperatures in Australia going to new levels, um...
Justin Webb: Trouble is, we report those, and we're interested in them. There is an effect, isn't there, that is possibly an obfuscatory effect, actually, on the real picture, and you accept that that might be the case.
Brian Hoskins: Absolutely, and we have to be very careful to not say "Oh, there's records everywhere, therefore climate is changing". But we're very sure that the temperature's risen by about 0.8 degrees, the Arctic sea ice has reached a minimum level in the summer, which hasn't been seen for a very, very long time, the Greenland ice sheet and the West Antarctic ice sheet have been measured to be decreasing. There's all the signs that we are changing this climate system. Now as we do this, as the system warms, it doesn't just warm uniformly. The temperature changes by different amounts in different regions. And that means the weather that feeds off those temperature contrasts is changing and will change - it's not just a smooth change, it's a change in the weather, it's a change in regional climate we can expect.
Justin Webb: Lord Lawson?
Nigel Lawson: Yeah, I think we want to focus, not on this extremely speculative and uncertain area - I don't blame the climate scientists for not knowing. Climate and weather is quite extraordinarily complex, and this is a very new form of science. All I blame them for is pretending they know, when they don't. But anyhow, what we want to focus on is what we're going to do. And I think this is a wake-up call. We need to abandon this crazy and costly policy of spending untold millions on littering the countryside with useless wind turbines and solar panels, and moving from a sensible energy policy of having cheap and reliable forms of energy to a policy of having unreliable and costly energy. Give up that - what we want to focus on - it's very important - is making sure this country is really resilient and robust to whatever nature throws at us, whether there's a climate element or not. Water storage, when there's drought -
Justin Webb: Surely the wise thing... Can I just put this to you -
Nigel Lawson: - flood defences, sea defences - that's what we want to focus on.
Justin Webb: Can I just put this to you though: if there is a chance - and some people would say there is a strong chance - that global warming, man-made global warming, exists and is having an impact on us, doesn't it make sense, whether or not you believe that that is a 95% chance or a 50% chance or whatever, does it not make sense to take care to try to avoid the kind of emissions that may be contributing to it? I mean, what could be wrong with doing that?
Nigel Lawson: Everything. The - first of all, even if there is warming - and there's been no recorded warming over the past 15, 16, 17 years -
Justin Webb: Well, that's - oh yeah, there is a lot of controversy about that.
Nigel Lawson: No, there's not - that's a fact. It's accepted even by the IPCC. No measured warming -
Justin Webb: No, no measured warming , but... Well, all right -
Nigel Lawson: No measured warming, exactly, well, that's -
Justin Webb: We'll get back to that.
Nigel Lawson: - measurements are actually not unimportant. The - but what - even if there is some problem, it is not able to affect any of the dangers, except marginally. What we want to do is to focus on dealing with the problems that there are, with climate - which there are, with drought and floods, and so on. These have happened in the past - they're not new. And as for emissions, this country is responsible for less than 2% of global emissions. Even if we cut our emissions to zero - which would put us back to the, sort of, pre-Industrial Revolution, and the poverty that that [inaudible] - even if we reduced and did that, it would be outweighed by the amount of the Chinese, China's emissions' increase, in a single year. So it is absolutely crazy, this policy -
Justin Webb: Sir Brian?
Nigel Lawson: - it cannot make sense at all.
Justin Webb: Sir Brian?
Brian Hoskins: I think we have to do - to learn two lessons from this. The first one is that by increasing the greenhouse gas levels in the atmosphere, particularly carbon dioxide, to levels we've not seen for millions of years on this planet, we're performing a very risky experiment. And we're pretty confident that that means - if we go on like we are - that temperatures are going to rise somewhere 3 to 5 degrees by the end of this century, sea levels up to half to one metre rise -
Justin Webb: Lord Lawson was saying there, there has been a pause, which you hear a lot about - a pause in what, 10, 15 years, in measured rising of temperature. That is the case, isn't it?
Brian Hoskins: It hasn't risen much, over the last 10 to 15 years, if you measure the climate from the global averaged surface temperature. But during that time, the excess energy has still been absorbed by the climate system, and being absorbed by the oceans, which are warming up.
Justin Webb: So it's there, somewhere.
Brian Hoskins: Oh yes, it's there in the oceans. And the oceans -
Nigel Lawson: That is pure speculation.
Brian Hoskins: No, it's a measurement.
Nigel Lawson: No, it's not, it's speculation, with respect.
Justin Webb: Well, it's a combination of the two, isn't it, as is this whole discussion. Lord Lawson, and Sir Brian Hoskins as well, thank you both very much.
Brian Hoskins: Thank you.