Source: Climate Assembly UK
URL: https://www.climateassembly.uk/
Date: 25/01/2020
Event: Climate Assembly UK, Weekend 1: Panel 1
Credit: Climate Assembly UK, Just Transcription
People:
[Contains public sector information licensed under the Open Government Licence v3.0.]
[Professor Joanna Haigh, Imperial College London: What climate change is: Panel one.]
Tim Hughes: But now it's time for our first panel. This panel is going to focus on an introduction to climate change. So we're going to hear from four speakers. So the first speaker we'll going to hear from is Joanna Haigh from Imperial College London. And she'll be talking to us about what climate change is. Then we'll hear from Professor Ed Hawkins from the University of Reading, and he'll be talking about the impacts of climate change. Thirdly we'll hear from Professor Rebecca Willis, who is one of our expert leads from the University of Lancaster. She'll be talking about why tackling climate change has proved a difficult issue in the past. And finally we'll hear from Chris Stark, also one of our expert leads from the Committee on Climate Change. He'll be talking a bit more about what we as an Assembly are going to cover. So, as I said, the speakers will speak - they'll each speak for about 10 minutes - and they you'll have an opportunity to at your tables note down those questions. So without any further ado I'm going to hand over to our first speaker, so Professor Joanna Haigh.
Joanna Haigh: Well thank you very much - it's a real honour to be here and I hope I'll be able to introduce climate change in a way that is accessible to you all. I should have a talk somewhere (indecipherable). A ha, introduction to climate change.
So first of all, what is climate? We all know what weather is, you know, it's sunny, it's windy, it's hot or cold. And we can measure those things - we can measure the rainfall. And climate is essentially the average weather for a particular place. So you might say that the average maximum temperature in Birmingham in January is 7 degrees Celsius. And that would be the climate of Birmingham. But the weather from day to day might of course be warmer or colder than that. So the highest temperature ever measured in Birmingham in January is 15 degrees. So another important part of climate is how often do we get these extreme temperatures? So the average temperature is 7, but how often does it go above 12, say? So all those statistics will be collated and then we understand what the climate of Birmingham, or the West Midlands, is. And climate change is just when there's a long term shift in those conditions. So we have long term measurements, measurements over years and decades of those parameters and we see whether or not the average temperature and the extremes have changed.
So how do we know that? Well there's measurements of all these climate parameters in a number of different ways. Since about the 1970s there's been satellites. So satellites go round and round the world all the time taking these measurements, and they're provided of course for the weather forecasters. So the Met Office will get these data all the time. But the climate people can collate all these data, collect them and analyse them. And we've now got forty or fifty odd years of satellite data telling us what the temperature has been doing over the world. But going back further than that, there of course weren't satellites, the instrumental period - so thermometers could be used from about the 1850s, and they've been at various weather stations over the globe. And again, the data is collected and analysed. And that's a very careful subject that needs to be done, taking into account all sorts of factors about different thermometers in different places and whether the air has changed in terms of urbanisation and that sort of thing.
So very carefully collected data over the world. Going back over longer periods, so over thousands of years we can tell what especially the temperature and the humidity has done from looking in indicators like in tree rings and in corals and in stalagmites and ocean sediments. They can tell us what the temperature and the humidity has done over these very much longer periods. And indeed if you want to go over hundreds of thousands of years, we can look at the air trapped in ice cores. They take cores from the ice in Antarctica and Greenland and measure the air trapped, and they can tell from that what the temperature and the humidity was at that time. So these are the sort of records that are used to find out what climate is and whether or not it has changed.
So these are the instrumental - the temperature measurements taken by thermometers over the last 170 odd years. You can see, it has different coloured curves there, and those different coloured curves are each analysed by different groups of scientists. So that's independent measurements, so you can see the slight differences between the colours, but they're generally saying the same thing. And then the grey shading is an estimate of what we think the range is. So, of course, measurements are not absolutely precise, so we need to know within what range we believe that to be true. And that's what the grey shading is telling us. So you can see that it starts off - it's sort of bobbling along, but it's fairly flat and then it starts about 1900 to go up, it flattens off, and then it starts going up again very sharply, so that nowadays the temperature is about - on a global average - one degree warmer than it was in the 1800s. And this is, of course, what's become known as global warming, and really it's the background to everything that we're here talking about today.
Now I need to go into a little bit of science - I hope this isn't going to put you off - but, to understand what is happening to the climate, we need to understand what is happening to what heats up and cools down the atmosphere. So all the energy that's driving the climate system, that's making the winds blow, that's making the temperatures, etc, is coming from the sun. There's a tiny, tiny bit of energy coming out of the centre of the Earth, but that's completely negligible compared with the energy coming from the sun. So if we look on a long term average – a global average, an annual average – and average everything else out, there’s a certain amount of heat coming in from the sun, and that has to be balanced – if there’s no climate change – with the same amount of energy going out. So what we’ve got is the solar energy coming in, and on the right there you’ve got some heat energy going out. And those have to be balanced. But what we find is that the energy coming in from the sun - about half of that gets to the surface of the earth and warms up the surface, and then that surface gets warm and it wants to put out heat – heat radiation. But the atmosphere is such – it’s composition is such – that only 10% of that escapes directly to space, and about 90% is absorbed in the atmosphere.
So the atmosphere itself gets hot - it’s made of material, it gives out heat in all directions including downwards. So then the surface is getting more heat than it had done originally from just the sun. And the temperature rises until everything else is balanced out, such that the radiation going into space is equal to radiation coming in from the sun, but the surface is warmer than it would be otherwise due to the composition of the atmosphere. And this is what we call the greenhouse effect. It’s a perfectly natural thing. In fact it’s a rather good thing – it’s a lovely thing because without the greenhouse effect, the temperature of the earth would be about 30 degrees colder than it is. And so life couldn’t have developed in the way it has on the planet. So in absolute terms the greenhouse effect is something we like – thank you very much. And the main greenhouse gasses causing that to be the case are firstly water vapour – so the water vapour in the atmosphere, that’s a very very strong greenhouse gas. And the second one is carbon dioxide, and there are smaller ones which I’ll mention later, but those are the two most important ones. So if we change the chemical composition of the atmosphere, we can change the effect of this greenhouse, and the temperature of the earth.
So let’s have a look at what factors cause the climate to change. Which factors will influence this radiation balance – this equilibrium – that we’ve got the earth in? So there are of course natural factors, for example, if there is a big volcanic eruption, it can chuck a whole load of stuff up into the air, and the particles can stay there for about two years. And when that happens, it reflects sunshine to space and there are measurable changes – cooling of the earth’s surface – so we know that big volcanic eruptions cool the planet temporarily. Then if we have changes in the sun – if the sun was to give out more or less energy, clearly, that would cause the global temperature to go up or to go down. It also responds to changes in the earth’s orbit around the sun. So those are the natural factors. In terms of human factors, I’ve already mentioned greenhouse gasses. So if we add to the greenhouse gas composition of the atmosphere, that will cause the surface to warm. And other factors – so, I put industrial pollution. If we put a lot of particles up into the atmosphere from industrial processes, or perhaps agriculture or whatever, they can act like that volcano I mentioned earlier and can reflect radiation to space and cool the atmosphere down. And also changes in agricultural land use can affect the climate – Jesus, I’ve only got two minutes left, oh dear. So for example, if we cut down a lot of trees, they won’t be absorbing the greenhouse gasses that they were before. Or if we cut down a lot of trees and make the surface brighter, that will reflect sunshine to space.
Now, perhaps I will miss the bit at the bottom, but I can answer questions about it later. Sort of factors that add or reduce from the initial forcing factors.
So greenhouse gasses – I’ve mentioned carbon dioxide – and the human produced greenhouse gasses, about three quarters of them are carbon dioxide. We can’t add to the water vapour in the atmosphere, because as soon as - if we were to try and put more in, it would just rain out again – it’s sort of controlled. So there’s carbon dioxide coming from fossil fuels, mainly, and land use, and then the next most important ones are methane and nitrous oxide, which are largely associated with agricultural practices. So this is a measure from Hawaii – so that’s right out in the middle of the Pacific Ocean, so very clean air, it’s not coming from the local industry or anything – of the carbon dioxide concentration of the atmosphere. This is quite an incredible picture – and it’s showing that since 1960 the composition has gone, in these units, from 320 to over 400 units. So that’s very clear indication that carbon dioxide has been increasing. And if we go back even longer in time, that little red mark there is what I just showed you, but the rest of the picture is carbon dioxide concentration over the last 800,000 years. So you can see over the last 800,000 years the carbon dioxide has never been as high as it is today, and in fact it’s probably higher than it has been for 3 million years.
And I said that here. We know that the increase is mainly due to the combustion of fossil fuels, and there’s several reasons how we can deduce that, which I can answer questions about to anybody that wants to ask. Carbon dioxide remains in the atmosphere for about 200 years. It just goes up there and it stays there. There more we put up, the more that stays there. It’s going to accumulate, and these are the countries that are responsible for the accumulation. So, of course, when the industrial revolution started in the 1800s, if we’d looked at which country was most responsible, that would have been the UK, and we started everything off. We were responsible for kicking it all off. And the biggest country up there would have been the UK. But now if we look in 2018 who has been most responsible for the current state of emissions, the total that is in the atmosphere now, the biggest one is the USA and we’re down there at fifth. So we’re not a minor contributor even now.
And this is an important graph – it’s showing temperature – the black line there is the same temperature graph I showed you before: warming from 1880 to the present time. So that’s the black line. And the grey lines are calculations from computers. The big computers that are used to forecast weather can also calculate climate. There’s two sets of calculations there – the bottom set is only natural drivers, so we run the models with the factors, only the changes in the sun and the volcano that we know has taken place and we look and see what happens to the temperature. You can see it’s going along, there are some spikes due to volcanoes, and there’s a spread of uncertainty but it’s carrying along – it doesn’t have the global warming. And it’s only when we put in the human factors, which is the largely greenhouse gasses but the industrial processes and all the rest of it, that we can match the observations of temperature.
This is my final slide – she’s smiling! We know that the global temperature rise is due to the accumulation of greenhouse gasses. And it’s accumulating – the temperature is responding to the accumulated amount of CO2. So if we wanted the temperature rise to stop at a particular temperature level, we’ve got to stop the CO2 rising. That means we’ve got an absolute total amount of CO2 that we can put in the atmosphere before we go above that temperature. And that amount of CO2 is called the carbon budget. If we carry on going past what we know is the carbon budget for global warming of, say, 1.5 degrees, then something needs to be done to take the carbon dioxide back out of the atmosphere again. And I think – the bottom one – keep warming below 1.5 degrees means reducing emissions to net zero by 2050 – approximately. So we’ve got to slow down emissions and stop them to effectively zero by 2050. Sorry for going too long.
Tim Hughes: Thank you very much, Joanna.
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[Professor Ed Hawkins, University of Reading: Impacts of climate change: Panel one.]
Tim Hughes: So next up, we have Professor Ed Hawkins from the University of Reading talking about the impacts of climate change. Over to you, Ed.
Ed Hawkins: Good morning, everyone. So, first of all, thank you very much for all being part of this amazing process. We appreciate your giving up a lot of time to be here. So as Joe's just described, we've understood the basics of the greenhouse effect for a very long time. The basic physics and chemistry of our atmosphere means that if we add more greenhouse gases to the atmosphere, it will warm up. Of this we're certain. So we understand the theory, if we add greenhouse gases to the atmosphere, it will warm up, and that is what our thermometers also tell us. So, as Joe described, we have thermometer measurements covering the planet. We can reconstruct our global temperatures back to about 1850. And so those measurements show that if we start at 1850, so one strike represents one year. The blue colours represent cold years, the red stripes represent hot years. So starting in 1850, we see mainly cold years, and as we go forward through time up to the present day, the stripes get redder and darker, showing that the planet is warming up and that rise has accelerated in the last 40 or 50 years or so. We are changing the climate. Now, we've warmed the planet by about 1, 1.1 degrees so far. That may not sound like very much, and on a day like today if you walk outside, you may not feel the difference between 8 degrees or 9 degrees outside. But when we average that over the planet, that has very severe consequences. So we're gonna start, about some of those consequences in the Arctic. But first of all, I should note that what we're seeing here this warming of our climate, is happening everywhere. It's happening in every country, and it's happening over the oceans as well.
So, we have satellite measurements over the Arctic. We've looked down on the North Pole since about 1979 from satellite, and over that time we've watched the sea ice. Over that time, we've watched the sea ice slowly decline over time. It wobbles around from year to year, but over time, over the last 40 years, we've lost about 40% of the sea ice cover in the summer over the Arctic. And of course, that 1 degree rise in global temperatures is actually about 2 degrees in the Arctic, and that means that there's more opportunity for ice to melt. And so that's what we're seeing. We're seeing the consequences of a warming planet on the sea ice. And this is also the natural world telling us that something is happening. The natural world is responding. It's telling us the same stories as our thermometers. We're seeing the changing seasons as the natural world responds. We're seeing wildlife respond to the warming planet, and we're seeing the ice respond as well. We are warming the planet. And as well as the sea ice retreating and getting thinner, we're also seeing the melting of Greenland, for example. Greenland is losing water at a rate of three Olympic sized swimming pools every single second. That's a lot of water entering the ocean and causing sea levels to rise. We'll come back to sea level in a moment. And this, of course, this melting in the Arctic and warming of the Arctic has consequences for those who live in the Arctic, people, and the wildlife who live there and are used to the climate of the past, and we're pushing them outside the climate of the past and making them live in a new climate in which they may not be adapted to.
There are other consequences as well. I'm sure you won't have missed the bushfires in Australia over the last couple of months, and this photograph was taken by a firefighter having to think about how to deal with this inferno in front of him. Because the reasons for the bushfires in Australia are many and they're complex, and at the heart of it is actually some unusual weather conditions which has led to some very hot weather and some very dry conditions. You can see the grass and the photo is very dry. Many of these areas have been in drought for the last three years, which has meant the area's very dry and very flammable, coupled with the unusual weather conditions has meant that fires have been likely. So, the fires would have happened without climate change. But climate change has made it worse, because we have warmed the climate, we've warmed the temperatures in Australia, this event was hotter than it would otherwise have been, which has meant the fires are worse than they would have bean without climate change. It's also possible, likely, in fact, that we've affected the weather patterns around Australia and dried out some of the parts of Australia where these bushfires are happening. When we warm the planet, we shift the atmosphere's circulation, and so storms go in slightly different directions than they would otherwise have done, and so over the last 40 or 50 years, parts of Australia which have experienced these bushfires have shown quite a strong drying out as well.
So there's many different ways in which climate change can affect these events that would have happened anyway, but we are making these events worse than they would otherwise have been. How about closer to home? So is Joe described, we have thermometer measurements all over the world, and we have some very long records. For example, from Oxford. So in Oxford we have temperature measurements. So someone has measured the temperature every single day in Oxford, at the same place since 1814, every single day. So we can look back over those 200 years and see how temperatures had changed in Oxford. Again, the same stripes we see going from 1814 on the left to 2019 on the right. The blue years are the cold years, red years are hot years. And again, we can see the pattern of our warming climate even at the scale of a single thermometer based in one town in the UK. Climate change is here and now.
Interestingly, the very dark stripes we see, they're volcanic eruption years. So we know there are some big volcanic eruptions in 1815 and in the 1830's and in the 1880's, which we can see cooling the climate in Oxford, for example. But at the end, we can see that there's very strong warming signal. As our climate has warmed, we're seeing the temperature rise everywhere across the UK and in every country around the world. So what does that mean for us in the UK? So if we think about the recent heat waves that we've had in 2018 and 2019, we had some very hot weather as well. Similar to Australia, what we see is that the hot weather caused hot temperatures, but the temperatures were hotter than they would otherwise have been without climate change. We've added extra extra heat to those events. We're making them warmer than they would otherwise have been. In 2018, we saw big problems in our railways and our roads because they're not used to dealing with this amount heat all the time. And so our infrastructure isn't necessarily adapted to the conditions that were pushing our climate into, and that is causing the consequences.
Also in the UK, I think one of the main risks for the UK from a warming climate is probably flooding. So this picture is from 2015. We had some very severe floods in Somerset. I'm sure many of you remember, this picture is of a flooded village back then. Climate again, this event has many and varied complex reasons for occurring, but ultimately it comes down to how much rain fell from the sky. So for this event, we had lots of storms coming across the Atlantic and hitting the UK as we do every every winter. There's nothing particularly unusual about any of those individual storms. They all dropped their rain in the same place, which caused a lot of the flooding. So how has climate change affected an event like this? Because we're living In a warmer world, the atmosphere can hold more moisture. Again it's very simple physics. A warmer atmosphere holds more moisture, more water, so when we get a storm dumping a lot of rain it actually rains more than it would otherwise have done. So we're seeing more rain than would have occurred in the same storms 100 years ago, so that they were getting more rain, potentially leaving more flooding at events like this. That is how climate change is affecting us, as people and our ecosystems, it's by making extreme weather events worse, and the impacts of those events worse.
So, the world faces very different risks depending on where you live. There are a whole load of risks that you might think about the consequences of our warming world. I've discussed some of them already, so we are likely to - well we will experience and are experiencing more heat waves. We'll also see more floods, as I've described already. I've discussed sea level rise. The sea levels around the globe have already risen by about 25 centimetres or so, and they will continue to rise for centuries as the planet continues to warm, mainly due to melting of ice from say Greenland and Antarctica, but also the fact that as the oceans are warming, sea water expands as it gets warmer and so takes up more space in the ocean causing sea levels to rise. So those are the main two reasons why sea levels are rising, which means also that when we get storms, say hurricanes or typhoons or storms hitting the U.K, it means that when those storms hit the coast, the sea level is higher. So the water that's coming from the storm surge, as those waves break over the coast, the water's already higher. And so we get more flooding on the coasts as well.
Many of these risks are from the fact that we change our climate. We're shifting our climate out of what we're used to experiencing. So ecosystems and wildlife are adapted to living in a particular climate, and so if we're pushing the climate outside what they used to experiencing, that's gonna cause consequences. They'll want to move to another location, perhaps, but there may be nowhere to move to, and so that would cause consequences for them. Our infrastructure here in the UK and anywhere is adapted to the weather and the climate that were used to experiencing in the past. We need to think about how we adapt our infrastructure for the future to make it capable of dealing with future hot temperatures and more flooding.
We're also seeing that the fact that as we're adding more carbon dioxide to the atmosphere, some of that carbon dioxide has been absorbed by the ocean and actually turns into carbonic acid in the ocean. So we're actually seeing the oceans getting slightly more acidic through time as well. And that has consequences on wildlife living the ocean; corals and other species as well. The corals for example, in Australia, you may have seen have been struggling recently partly due to this ocean acidification, but also due to the fact that getting very hot temperatures and the coals are not used to experiencing those hot temperatures and so bleach and die. So large parts of the Great Barrier Reef had some very large problems in the last couple of years as temperatures have hit record highs.
So those are ones that we're very confident about, and there are other impacts that we may be slightly less confident about. So we might imagine that climate change adds to increased risks in certain areas. Many of these impacts are happening in vulnerable countries, and so if you are changing the climate, you may be making farming particularly difficult in a particular area leading to potentially people moving away, because they can't grow the crops that they used to experiencing. So migration is one thing that we think about. Climate change is what we call a risk multiplier: it adds to the risk that already happened due to the weather conditions. We're seeing glaciers been melting across the world, which means that many regions which are used to living off the melt water from glaciers will no longer have a water supply. For example, once the glaciers have gone. There are many and numerous different ways in which climate change is affecting how people will live on the risks that they face.
In the UK we'll have think about our infrastructure and potentially we'll see different diseases coming to the UK. These are all things that we worry about, we're less certain about, but they're potential risks that way will face. As Joe said, I think the UK, we built the Industrial Revolution. James Watt invented the efficient steam engine in the 1780s, which kick started the Industrial Revolution, which has been a great thing for a science and technology and medicine and how we live our lives. But now we're seeing the side effects of that development, and these are all the risks that we face now because of that development that we've experienced, and I think the UK has a great opportunity to be part of the next revolution. To try and tackle these risks, and reduce risks all across the world. Thank you.
Tim Hughes: Thank you very much, Ed.
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[Professor Rebecca Willis, University of Lancaster: Why tackling climate change has proved difficult. Panel one.]
Tim Hughes: One of our expert leads, and is on is going to talk to us about why tackling climate change has proved difficult. So over to you, Rebecca.
Rebecca Willis: Thank you. So as Joe and Ed have explained, we've known about climate change for a long time, but we haven't yet managed to act to cut carbon and those are the greenhouse gases by anything near the amount that we need to. In fact, if you look across the globe, emissions is still rising. And in the UK we have cut emissions but we haven't done anywhere near enough. So over the course of this Assembly you'll hear from speakers about how we could tackle climate change, and there are lots of good ideas. But before we do that, I want to talk about what's made it difficult so far. Why we haven't acted enough so far. I'm going to focus on three areas. The first is the way our economy works, the second is something about the politics of climate change, and the third is really looking our own reactions both as individuals and as a society.
So, let's look at the way the economy works. Our economy is dependent at the moment on fossil fuels like oil, coal, and gas. And it's burning these fossil fuels that causes the emission of carbon dioxide and other greenhouse gases. So, we use fossil fuels to make things in factories, to travel around, the petrol in your cars and to heat our homes. Even though we know about the damage that climate change causes, it doesn't cost us any money as individuals to do this damage. So when you switch on the heating in your home, you pay for the gas, but you don't pay for the pollution. And because no one owns the Earth's atmosphere, no one charges you for polluting it. Neither does it cost companies who might be polluting the atmosphere as well. There's no charge to them at the moment. And also we've been using fossil fuels for such a long time that they've shaped the way that we live and work. So, for example, people travel much further now than they did 100 years ago before cars were common, and now people might commute quite a few miles to get to work, people need a car to get to the shops or to get to school. And that's because our towns and cities have become designed for car use. We've created a society that depends on large amounts of energy, and most of that until now we've got from burning fossil fuels.
So this can change. We can move away from fossil fuels, but it will mean changes to the way that we live, and work, and travel, and changes to what we eat. And over the next few weeks, you will be hearing about these changes and many of them have got added benefits. So, for example, if we stop driving cars powered by fossil fuels, then this improves air quality and helps people with asthma. But it is a change, and changes can be unsettling and difficult. And there are some people who will actively oppose that change. There's good evidence, for example, that oil companies have opposed action on climate change because they worry that it will affect their business. And similarly, carmakers have opposed regulations that might make cars more efficient.
So let me turn now to the politics. As we've heard, climate change is a problem that the whole world faces and it's unfolded over many years, and this makes it a challenge for politicians and they've often avoided the problem. It's difficult for them because while climate change happens a global level, a government is only in charge of one country. Only a small percentage of greenhouse gas emissions come from the UK, for example. So, you sometimes hear people saying "why should we cut our emissions if other countries aren't cutting theirs?" The truth is that we need all countries to play their part, and every single country has signed the Paris Agreement on Climate Change and agreed to act. Each country will respond in different ways, but they have all pledged to meet that target. There's a strong argument that the UK should lead the way because we've benefited from fossil fuels for a very long time and we're a relatively rich country, so we can invest in climate solutions. So another political problem is the time frame. As we've heard, climate change has been happening for decades, but the changes have happened gradually up until now. There's no obvious link between greenhouse gases that are emitted today and their long-term effects on the climate. You can't look out of the window and actually see it happening. So, this makes it difficult for politicians to act because it's hard to see those changes during the lifetime of one parliament, which at the most is five years.
And then, lastly, I want to look at our own reactions. I want to think about how and as individuals and together as a society we might be thinking about this problem. And climate change can be quite frightening to think about, and hearing about events like the bushfires in Australia or the floods there have been in the UK, it worries people. It is worrying too if you think about the future, if you think about what happens, for example, if climate change begins to affect food supplies and the way that we grow our food, and if climate change affects crops. Psychologists have shown that people have ways of dealing with worries like this, and it's really worth bearing those in mind as we go through our discussions. So, the first thing that people often think is "it can't be true". They might ignore the scientific evidence, and because you can't see climate change directly, you can only see its effects. It is possible to do this. Or you might think, "well it can't be as bad as all that", or, "it'll all work out okay". And again psychologists have shown that people do this because they might not want to think about something that is difficult or that is frightening. And these are really natural reactions and they can be useful ways of coping with difficult things, but they also might prevent us from facing up to something that really needs our attention.
Another common reaction is, "well if it's so serious, why isn't everyone else worried?" And that's because people tend to look to those around them, to friends, to family, maybe to the media, or people they respect in public life, and they see how they're reacting. And again, this is a very sensible thing to do, to take your cue from other people. But for climate change, its actually made the situation worse. Sociologists who study society and social change have shown that climate change hasn't been talked about very much, and this makes people less likely to talk about it themselves and less likely to act. It's a bit like if a fire alarm went off in this hotel now, you might initially be worried, but if no one else got up and walked out the door, you would think, "oh it must be okay", and you might stay where you are.
And lastly, it's common for people to think they will find a way to fix it. "If climate change is so serious, then surely we can invent something that will make it better." And it is true that there have been a lot of advances that offer help to tackle climate change. One example is solar power, which has got cheaper and more efficient and will help us to provide electricity without fossil fuels. But scientists are agreed that there's no one single thing, no one magic bullet that will help. Instead, it will be a combination of lots of different things, some new technologies, some things that aren't new inventions at all, like planting trees, and some changes to the way that we live, like changing what we eat.
So, to summarise, climate change is a really difficult issue to tackle, because fossil fuels which produce greenhouse gases have been a really important part of our lives up until now and moving away from fossil fuels will mean changes to our lives. Secondly, because politicians find it difficult to cope with a problem which is global and unfolds over a long time. And thirdly because it can be difficult to face up to the facts on climate change both as individuals and as a society because it's often easier to turn away. So as you take part in discussions over the coming days and weeks, there are a few questions that you might want to come back to, that you might want to ask yourselves and each other. One of them is why haven't we managed to act sooner on climate? What's been stopping us until now? And how can we overcome those barriers? You might want to ask what or who is opposing the changes and what do we do about that? What do we do about people who might be opposing changes which could help? And lastly, you might want to ask, how am I reacting to this personally? Am I worried? Can I share those concerns with people? Am I maybe ignoring things that I find difficult to cope with, and who else out there might be ignoring or trying to avoid these difficult questions? And I think that if we bear this in mind as we go through the Assembly will help us to have that really honest and open discussion that we need to have. Thanks.
Tim Hughes: Thank you, Rebecca.
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[Chris Stark, Committee on Climate Change: What the assembly will consider. Panel one.]
Tim Hughes: So up now is Chris Stark from the Committee on Climate Change. He is also one of our expert leads and he's gonna be talking a bit more about what you're going to cover as the Climate Assembly. It's over to you, Chris.
Chris Stark: Thanks Tim. Morning everyone, I'm Chris. You're going to see a bit for me over the course of actually this-this weekend, and future weekends as well. So how you feeling? Good good. So just a very quick recap of what you've heard. So you've heard about what climate change is, the scientific basis for it. You've heard from Ed about the impacts of climate change and you've heard from Becky about why it's so hard to address the problem. And let me tell you, those presentations could have easily been a day each. So we're trying to cram a lot in, we know that. So what I'm going to do in this section is to talk just a bit about the UK, to talk about the target that the UK has, which we call this net zero target and then give you a sense of in the UK what's driving the emissions that we'll be talking about over the next four weekends, and what you're gonna do. So that's-that's the that's the point really of my section here. I'm gonna try and keep this section as factual as I can. And I'm sure there will be questions, and if you have them, I'll do my best to answer them afterwards.
First, a point on what we're talking about today, so the UK is net zero target. And let me just briefly explain what that means. So net zero has, is both a term in science, it's a thing that really means something, but it's also become a-it's become a term that you see used publicly as almost like a badge for something. So it's important that we define it. And basically, it means reducing in the UK the greenhouse gas emissions that we are producing here to as low a level as possible, and then for whatever emissions are left, having gone through that process, having something that balances them on the other side. So that might be what I mean by that is something that absorbs carbon dioxide, greenhouse gas emissions, carbon dioxide from the atmosphere and that nets them off. So that might be through growing a tree, for example. It may be through some of the more technological approaches to taking that from the atmosphere, but that gets you to overall zero. So it's-it's, that's why it's net zero overall, we'll use that term a lot, but it's important to say here what it means. In the UK that target is about emissions that we actually produce here. Now sometimes that's called territorial emissions. That's the emissions that happened within the territory of the boundaries of the United Kingdom.
But the other thing I wanted to say here is, although that's the basis of the UK target, there's a bigger story here going on which you will hear about, about what's sometimes called our carbon footprint. And we have a bigger carbon footprint than those emissions than just those emissions that we produce here in the UK. So think about the things that we import in particular. Think about something like steel, for example. So steel it is a thing that is produced through an industrial process, and a lot of the steel that we use is imported from another place. And that industrial process has emissions associated with it, and what we import therefore means we are responsible for something that happens outside the UK. Now, if you look at that-that question that sometimes called consumption emissions, because we're consuming that product, there is a bigger number associated with that and the emissions we produce here. So it's a bit 50% or so bigger than the emissions that we actually produce here. So we are responsible for something a bit more than just the emissions that are produced here in the UK. But the emissions just in the UK are still the biggest part of our impact on the climate. So it's the biggest, it's the biggest thing that we are responsible for. Those things that happened in the UK. I'm gonna talk you through very quickly what those are those production emissions overall. That's what we're looking at. That's what the target's about. But we should have it remind the the bigger part of this, too.
Let's just talk then, about these greenhouse gas emissions and what we produce here in the UK. Um, overall, we've actually been cutting our greenhouse gas emissions for a long time, actually, for several decades since probably about the seventies. And that's a great story, because we are now, instead of being responsible for that very large part, just as Joe said of the problem in any one year, we're now actually going to cut a small part. So the UK is responsible for a relatively small amount of emissions each year. If you look historically, just as Joe said, we have a much bigger role to play. We're number five on the list of countries that have added to the problem of climate change overall. But in any one year now we're going to (indecipherable) a low amount. Let's just look there for what we are producing each year. Now you might have this on your table. I'm going to look at this. This is a pie chart of the latest stats that we have on emissions from the UK. Um, let's see if we can get this working. Right.
The first part of the pie chart, we're gonna go through in order the emissions from biggest to smallest in each of the - in each of the sectors as you may call them of the UK. The biggest one, I don't know if this is surprising to you or not. The biggest one is surface transports. This is mainly about cars, vans, heavy goods vehicles, and the petrol and the diesel that they burn. And if we look at that, it's nearly 1/4 of the emissions produced here in the UK overall. That is now the biggest sectoral contributor to the problem of UK emissions overall.
The next one is industry. That is industrial emissions, which is just over a 1/5 of the greenhouse gas emissions produced in the UK. And more than half of that is from manufacturing processes, which use a lot of fossil fuels typically. And another, 40% or so is from refining producing fuels. So in places like refineries, you'll find that. So that's overall 60% manufacturing 40% of refining gets you to that 21% of UK emissions of (indecipherable) from industry.
Um, this is something you will talk about a lot over the course of the next four weekends together. And that's buildings. Now, what I mean by that is buildings, that's your home, but also where you might work. So retail premises, but also buildings in the public sector too, so that's buildings. We'll look at that overall. The direct emissions from buildings come from heating them. So it's the fossil fuels that we use to heat, as gas typically. Most of us are on the gas grid in the UK and we burn natural gas, which is a fossil fuel, to create heat. And those emissions overall, which are mainly carbon dioxide, make up 18% of the total emissions from the UK. You also in your homes on in your places of work use electricity. Now electricity also has emissions associated with it, which I'll come on to in a second. We count them somewhere else in this pie chart. That's from the place where they're produced. So there is an indirect emission from the electricity that we use for these lights, for example, which I'll come onto in just a second. But this is about buildings, so just under 1/5 of the emissions in from the UK in any one year come from the emissions from buildings overall.
The next is that section I just talked about. This is electricity generation, and it's an interesting-an interesting sector because this used to be the biggest sector in the UK. This is used to use-burn a lot of coal, which is a particularly important contributor to the global problem of greenhouse gas emissions-cum-dioxide emissions. And the UK used to burn a lot of coal. Now it doesn't burn very much coal for the purposes of generating electricity overall. It used to be, but down about 70% actually from where those emissions stood in 1990. And the reason that's happened is because we switched from coal to alternatives, which have lower carbon emissions. That's also an issue that you're gonna hear a lot about over the next few years, how that electricity is supplied to you overall. But at the moment, electricity generation down now to 13% of the total in the UK in any one year. These are the most recent stats.
Next is aviation, which is a topic that is very often associated with climate change in general, and it may be surprising to you, but aviation is 8% overall of the total emissions. By far the biggest part of that 8% is international trips by plane. Actually, it's well over 90% of the emissions that come from aviation are associated with long haul flights, only 4% are the domestic emissions overall. That's the carbon dioxide that comes from burning aviation fuel and those planes. We have really good evidence and data on that, they're getting smaller now.
This is agriculture and land use. Now this is a very topical thing. This is basically the food that you eat has emissions associated with it. That is, in particular from the life stock and this particular type of livestock. Not all animals, but some animals in particular, cows and sheep create methane. They burp, and that methane is particularly potent as a gas that warms the atmosphere and we get that from our agricultural emissions. Agricultural emissions and land use. Now this is important because land use is what scientists call a carbon sink. So what does that mean? It means that land use is where you find a place where you can actually store emissions. So imagine growing a tree or imagine the soils that in certain areas people in soil, for example, can absorb carbon. And overall, we're just at the point where that is, that is a negative, but not very strong negative in the UK so we have a sort of slight carbon sink from our land use, plus agriculture (indecipherable). It means that we have 7% of the total emissions in the UK. That might be an area, when you're thinking over the next four weekends that we wanted to do something with. So you hear a lot about growing trees, for example. That's something that's very relevant to this discussion. There's also some emissions in there from the things that happened on farms, from what we do with agricultural soils, how we manage waste manure. These are all emissions too, but they're all in that figure there but that's 7% of the total overall. Nearly done. Next is waste. Emissions from waste are 4% of the total greenhouse gas emissions in the UK, any year, that's mainly from decomposition of biodegradable waste in places like landfill. So think of the food, for example, that you might throw out. That degrades and creates a greenhouse gas emission methane.
This is F gas. So what are F gases? Well F gases are really, you know, really striking thing. These are emissions, what we call fluorinated gases, and there are small proportion of the total here, but these are really, really potent gases. In fact, some of them are 23,000 times more - have more potential to warm the atmosphere than a particle of carbon dioxide. So really, really potent things. You might ask what we therefore use them for. Well, they're very, very useful as refrigerants, as aerosols. I don't know if we have any asthmatics in the room, but you can get it if gas is occasionally and the things that you squirt. They have a particularly useful role as a gas that can insulate. So they're used quite extensively, for example, in electricity and the electricity sector. in the insulation around pipes. They're really damaging in the sense that they're really warming to the planet. But of course, the very useful things as well. So although they're all very small amounts, they have a very big impact if they're released into the atmosphere. So it's 3% of the total in the UK comes from F gases. And the last section is another travel issue, is shipping. Shipping emissions, just 3% now of the total UK greenhouse gases. Most of that is from just over half of the runners from international journeys, and it's the fuel that's burned in ships, ships and boats.
So that's the pie chart. Now, the Net zero target for the UK is really all about this. It's about what you do to reduce the emissions from these sectors as much as you possibly can, and then netting the remainder off with something on the other side to absorb whatever's left at the end of that. That's what you're going to discuss. And very sure order, this is the topics that we will be covering in the Assembly over this weekend and the following three weekends. We've already been talking about the first of these, of course, which is our information of climate change and the UK's net zero target. Hopefully, these will know makes sense to you. What we're going to do, in no particular order, is look at energy supply. So what can we do about emissions associated with the supply of energy. We're going to look at how we travel, what changes can be made there, the energy that we use in the home. Just as I mentioned: food, farming, use of lands, what we buy, what we consume. And then that last point about how you actually remove gases from the atmosphere and the various approaches to that overall. So that's what's coming up. You'll hear a lot more from me after lunch, but that's enough for me for now.
Tim Hughes: Thank you very much to Chris.