20180726_BB

Source: BBC News

URL: N/A

Date: 26/07/2018

Event: Temperature rise "probably about 4 degrees by the end of this century"

Credit: BBC News

People:

    • Christian Fraser: BBC broadcaster
    • Pallab Ghosh: BBC News science correspondent
    • Professor Joanna Haigh: Co-Director, Grantham Institute
    • Dr. Chris Hope: Reader in Policy Modelling, Judge Business School
    • Professor Corrinne le Quere: Director, Tyndall Centre
    • Dr. Bjorn Lomborg: Author, academic and environmental writer
    • Dr. Friederike Otto: Deputy Director, Environmental Change Institute

[These segments were part of a special report on the BBC News Channel called Feeling the Heat.]

Christian Fraser: Now, more and more scientists are saying there's a closer link between carbon emissions and the rising temperatures around the world, but do these weather patterns that we're seeing fit the modelling that the experts came up with? Here's our science correspondent Pallab Ghosh.

Pallab Ghosh: The last time it was so hot in Britain for so long was during the long summer of 1976. The country went wild and Abba was in the charts. There were droughts - thousands had their water cut off, and people had to collect their supplies in buckets from standpipes. This was the temperature map at the time - the heatwave in red localised to parts of Europe, the US and Russia. Now look at this year - it's all across the northern hemisphere, where it's summer. Scientists have been studying whether there's a link to climate change. They feel that they now have the answer.

Joanna Haigh: Absolutely, yes. Perhaps, you know 15, 20 years ago we would have said "Well, it's possible but we really can't say whether a particular weather event can be ascribed to climate change". Now it's becoming much clearer that we can, with quite a lot of confidence, say that something like an extreme weather event is linked to climate change, or at least it would be very unlikely to have happened without climate change.

Pallab Ghosh: This is how the average June afternoon temperatures have been rising in Britain since 1900. And the trend is likely to continue, according to computer modelling. For decades, scientists have predicted that heatwaves, like the one we're having, will become more commonplace. It seems that that's now happening, according to their research. And their projections indicate that they'll last longer, become hotter and occur more often. In recent years there have been forest fires in California and in Southern Australia, which has suffered its worst heatwave in 100 years. Researchers at Oxford University have been assessing the impact climate change has had in Europe.

Friederike Otto: We have a very strong increase in heatwaves in the Mediterranean. It's not that strong in northern Europe but there also is an increase, and last year we looked at heatwaves in June and found there was a four times increase in Belgium and the Netherlands.

Pallab Ghosh: For many, the crazy summer of '76 is a fond memory from a bygone age. But climate scientists believe that these conditions are likely to become the norm, rather than the exception. Pallab Ghosh, BBC News.

Christian Fraser: Well, let's get into more of this - joining me to discuss this is Dr. Chris Hope, he's worked as a climate change advisor to the UK government and to the Obama administration and as a lead author for the 3rd and 4th Assessment Reports of the Intergovernmental Panel on Climate Change, which won a Nobel Peace Prize in 2007. From Norwich I'm joined by Professor Corrinne le Quere, Professor of Climate Change Science and Policy at the University of East Anglia, and she's the Director of the Tyndall Centre for Climate Change Research. And from Prague I'm pleased to welcome Dr. Bjorn Lomborg, who is President to the think tank the Copenhagen Consensus Centre, best known for his book The Skeptical Environmentalist, which challenges some of the presumptions, when it comes to climate change. Welcome to you all.

Corrinne, if I could start with you, I'm just going to bring up the maps that were in the report that we just saw, which compare the heatwave in 1976 with the heatwave of today, 2018. And when you look at the picture 42 years ago, you see there that the UK was the exception, more or less. Now, if you look at the 2018 heat map, you'll see that there's an awful lot more red across the planet. And particularly striking is the heat at the polar regions, as well. So what do you think is happening?

Corrinne le Quere: Yeah, we should really not be surprised with what is happening now. Climate change is causing - is increasing the risks of a heatwave around the world - this is well-known. It's causing longer heatwaves, that are warmer - hotter around the world. This is what is unique about the patterns that we're seeing now, and why we're increasingly confident that we can see a signature of climate change here, is that it's throughout the whole hemisphere - northern hemisphere summer. So having heatwaves - extreme heatwaves around the world at the same time is extremely unusual.

Christian Fraser: And does one heatwave lead to another heatwave? So, I mean, if you get a pattern of heatwaves and the Earth is warming up, does that then bring more heatwaves?

Corrinne le Quere: So this is part of a trend here that we are seeing. So we're seeing an increase, through time, and if we continue to cause climate change the way we have done in the past, then the risks of heatwave will continue in the future.

Christian Fraser: Dr. Chris Hope, if we go on emitting greenhouse gases at the rate that we're doing at the moment, how different will the world look in 2050?

Chris Hope: Well, up to now, we've seen a rise in temperatures of about 1 degree on average across the world. If we carry on on the path that we have been, that rise will be probably about 4 degrees by the end of this century, which is in the lifespan of a baby born today - will expect to be alive at the end of the century. Now of course, there's a little bit of uncertainty about that - it could be a 3-degree rise or a 5-degree rise, but if you can imagine the effects that we've seen with a 1-degree rise, we certainly want to avoid getting to a 4-degree rise, and to do that, we've got to make serious efforts to cut back our emissions of the greenhouse gases.

Christian Fraser: And with that 1-degree rise, we should therefore expect the patterns that we've seen this year to be repeated more frequently?

Chris Hope: Yes, you would expect, by round about the middle of the century, the kind of things that we've seen this year will become fairly normal. And, you know, beyond that, they will become more severe - heatwaves that we've seen, and in England it's been bad but of course if you get these kinds of heatwaves in Africa or in Asia, then you get into a circumstance where people really can't survive them. The temperature gets so high that you can't do any manual labour and you have to find shelter from those kinds of temperatures.

Christian Fraser: Bjorn Lomborg, your 2001 book was The Skeptical Environmentalist in which you argued that certain aspects of global waming are unsupported by the evidence. Have you shifted your opinion somewhat, since then, or do you accept that this is down to climate change or not?

Bjorn Lomborg: So absolutely, I mean, both Chris and Corrinne made it very clear and I think the evidence strongly supports - as temperatures rise, you're going to see more heatwaves. So I'm not contending that at all - that would be silly, that's the evidence and that's the data that we have, that's what the models show. It also makes good sense - as temperatures rise, you're going to see more heatwaves. The question that I have, and what I want us to emphasise, is two things. That we can't just focus on one part of this [?] - remember, right now maybe two - two and a half thousand people die from heatwaves in England, right now. But somewhere between 25 and 50 thousand people die from cold waves. So you have to both realise that as temperatures rise, you will see more heatwaves but you will also see fewer cold waves. And you need to talk about both of those.

The second part is: when we talk about - and I agree with Chris, that in the long run we definitely need to fix climate change. But we should also recognise if we actually want to help people who are stuck in places where it gets uncomfortably warm, there's much cheaper, much more effective and much faster methods to tackle this. So that's about making urban areas, where most people live - they are typically much warmer than the surrounding countrysides, so about that having more greenery, having more water features, having more cool features like white roofs rather than dark roofs - that can reduce temperatures much, much more than what temperature- than what climate policies can do.

Christian Fraser: Corrinne, is the global warming that we're witnessing, is that reversible? If we changed our behaviour?

Corrinne le Quere: So what we can do is stop further warming. So the warming that we have had, so far, I'm afraid is here to stay for a long time, centuries into the future. What we have the power to do is to limit the climate change that we will have in the future. But we have to realise that in order to do that, we need to bring down our emissions all the way down to zero. And that means completely moving away from using fossil fuel, oil, gas and coal to produce energy - we need to be completely renewable energy.

Christian Fraser: Okay. We may be able to do that, Dr. Chris Hope, but of course in developing countries, poverty is linked to the fact that they don't have energy and electricity - they're going to get it, fossil fuels are cheaper and will be cheaper up to 2040, so we might change our behaviour but there's no reason why they would.

Chris Hope: The problem with climate change is it's a wicked issue. It not only makes things difficult for us in this country but if you're already in poverty, then you will suffer more from climate change than people who are in rich countries. When we look at the impacts of climate change, about 80-90% of those are in poor countries, and they lead to people becoming poorer and poorer. So what we need to do is: we need to have the measures that might bring emissions down by 80% or 100%, as Corrinne was talking about, and that basically means having a climate change tax which has four characteristics - it needs to be strong, it needs to start off at about £100 per tonne of CO2, it needs to be comprehensive - it needs to be on all emissions, not just of carbon dioxide but methane - it needs to rise over time, because as we get to the middle of the century and things are getting worse and worse, if you emit one more tonne of CO2, then it has a bigger impact - and it also, very crucially, needs to be able to reduce other taxes in the economy, so we're not building up huge costs for everybody but we're able to reduce income taxes and sales taxes and national insurance. And employ people - we tax things we want to discourage, like emissions of greenhouse gases, and we take taxes off things that we want to encourage, like employing people and goods and services.

Christian Fraser: Okay. And we're obviously going to have to change the way we live - we're going to have to adapt, aren't we, with our homes and the clothes that we wear in the summer when we go to work, and various other things.

Chris Hope: It's quite likely that we'll have to adapt with our diet - more plant-based diet, because livestock contributes towards climate change - and we are locked into one or more degrees of temperature rise, as Corrinne has said.

Christian Fraser: Fascinating debate - I wish we had more time to get into it. Dr. Chris Hope, thank you very much. Thank you, too, to Bjorn Lomborg and also to Corrinne le Quere, for your company as well. Hope some of those questions have been answered through the course of our programme tonight - it's been an unusual few months, hasn't it. Stay cool - we'll leave you with some of the images of our global heatwave. Goodbye.