Zero Carbon Britain: Rethinking the Future (Centre for Alternative Technology, 2013)
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Using only current technology and acting in line with current climate science, we can reduce our greenhouse gas emissions to net zero whilst maintaining a modern standard of living. We can provide a reliable energy supply for the UK with renewable energy sources and flexible carbon neutral back up. Without fossil fuels, nuclear power, or gambling on the promise of future technology. We can grow the vast majority of the food we need for a healthy, low carbon diet, and manage our land to capture carbon, nurture biodiversity and increase the health and resilience of our ecosystems. We can create 1.5 million jobs, improve our wellbeing, and help ensure the future we leave for our children and generations to come is safe and sustainable. We have everything we need to create a positive future. Download the full report, 'Zero Carbon Britain: Rethinking the Future' for free (www.zerocarbonbritain.org) to find out how, or buy a copy online from the Centre for Alternative Technology Eco Store (www.cat.org.uk).
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Zero Carbon Britain: Rethinking the Future (Centre for Alternative Technology, 2013)
- 3. Climate change • New norms – temperatures increasing, arctic ice shrinking • New extremes – heatwaves, droughts, floods • More to come – both expected, and unexpected
- 4. Where we’re heading today
- 5. 80% reduction by 2050 At least net zero ASAP!
- 6. A technically robust scenario in which the UK has risen to this challenge.
- 7. Today: UK GHGs ~ 650MtCO2e
- 8. ZCB: net zero GHG emissions
- 9. ZCB shows that UK emissions can be reduced to net zero. Without nuclear power or gambling on future technology. Technically, we could do it now! Without major impacts on quality of life. (In fact, we think this future is better!)
- 10. We have to see the future like this No continuous ‘business as usual’ future is available!
- 11. Benefits beyond carbon • Potential for job creation ~1.5 million jobs. • Help us adapt and increase our resilience to climate changes. • Better outlook for biodiversity (and other environmental problems). • Improve our health and wellbeing.
- 13. How do we get from this…
- 14. … to this?
- 15. Two big questions: 1. Can we ‘keep the lights on’ with carbon neutral and renewable energy systems? 2. Can we provide a healthy balanced diet for the UK that is lower in GHG emissions and has positive impact on land use?
- 16. Energy in ZCB
- 17. UK GHG emissions today
- 18. The majority (though not all) of our emissions come from energy
- 22. From:
- 24. From:
- 28. Today
- 31. Supply Demand
- 33. Question 1: Can we ‘keep the lights on’?
- 34. The ZCB hourly energy model: Based on ten years of real-world hourly data 2002 - 2011 87,648 hours
- 41. Land use in ZCB
- 42. UK GHG emissions today
- 43. UK GHG emissions so far…
- 44. UK GHG emissions so far…
- 45. Agricultural GHG emissions today ~ 10% of UK emissions
- 46. Land use today • 65-70% = food production/agriculture • Despite 42% imports. • 85% of agricultural land = livestock.
- 47. Current average UK diet 64% of adults overweight/obese (Bates et al, 2011). 71% of deaths in 2010 from dietrelated disease (WHO, 2013). • Too much food. • An unhealthy balance. • Too much HFSS and high protein foods. • Too little fruit, vegetables and cereals. • Waste (30% in Europe (FAO, 2011)).
- 48. Question 2: Can we provide a healthy and balanced diet that reduces greenhouse gas emissions?
- 49. The ZCB food and diets model For over 60 different foods: • Emissions • Land use • Nutrition
- 50. The ZCB food and diets model • Healthy, balanced diet. • Low GHG emissions. • Using only land we already use for food.
- 51. ZCB scenario • Nitrogen inhibitors. • -50% waste. • Eat only what we need. • Product switch.
- 52. ZCB scenario • Nitrogen inhibitors. • -50% waste. • Eat only what we need. • Product switch.
- 53. ZCB scenario • Nitrogen inhibitors. • -50% waste. • Eat only what we need. • Product switch. • 5-6 portions meat/dairy/eggs. • 4 portions ‘alternatives’. • + Milk for tea/coffee.
- 54. ZCB scenario Agricultural GHG emissions -73%. • About a quarter of today’s grazing grassland is needed. • All cropland still used, but allocated differently. • Imports decreased from 42% to 17%.
- 55. Growing energy and fuel
- 56. Capturing carbon Safe, proven, lasting methods: • Restore 50% of peatlands. • Double forest area. • Increased use of UK wood products.
- 60. UK GHG emissions today
- 61. Net zero GHG emissions
- 62. ZCB shows that UK emissions can be reduced to net zero. We can provide a reliable energy supply to ‘keep the lights on.’ • 100% renewable/carbon-neutral. • No nuclear. • No gambling on future technology.
- 63. ZCB shows that UK emissions can be reduced to net zero. We can provide a healthy, balanced diet that is low in GHG emissions. • Better than today’s diet. • Has positive impact on land in the UK and abroad.
- 64. Benefits beyond carbon • Potential for job creation ~1.5 million jobs. • Help us adapt and increase our resilience to climate changes. • Better outlook for biodiversity. • Improve our health and wellbeing. A positive future.
- 65. We have the technology to power ourselves with 100% renewable energy, to feed ourselves sustainably and to leave a safe and habitable climate for our children and future generations. www.cat.org.uk | @centre_alt_tech www.zerocarbonbritain.org | #ZCB
Notas do Editor
- [OPENING SLIDE – Have this up when you start] Hello, my name is X, and I work as X at the Centre for Alternative Technology in Mid-Wales. CAT is focussed on finding positive solutions to the environmental challenges we face today. Zero Carbon Britain is a research and communications project that has run at CAT for about 7 years.
- This summer, we launched the third report of the Zero Carbon Britain project – Rethinking the Future – in parliament. It is available to download for free at this website, together with other resources [can give example of the Report in Short, if you are handing them out to attendees]. Or, you can buy a copy for about £15 online.
- So, why do we do the Zero Carbon Britain research project at CAT? Although there are many problems – both environmental and social – in the world today, the one we are most concerned about is climate change. Climate change is caused by emitting greenhouse gases, predominantly by burning fossil fuels – coal, oil and gas. --- We have already started to see the effects of burning those greenhouse gases. As a result of climate change, we are starting to experience new ‘norms’ and new ‘extremes’ in our climate. Temperatures are increasing. Temperatures on land have increased about three-quarters of a degree in the last 50 or so years. But most of the additional heat in our atmosphere has gone into the oceans, which has contributed to melting arctic ice. This picture shows, as an example, the difference in artic sea ice coverage in the summer of 1984, and today. Globally, we’re also seeing more frequent heatwaves, droughts, floods, and other extreme events. And more extreme versions of all of these. For example, does anyone remember the heatwave back in 2003? [I usually add a personal anecdote here as I was in Rome at the time and it was nearly 50degrees!]. That heatwave was the hottest heatwave we had experienced in Europe for over 500 years, by quite a long way. The concerning thing is that we know there is more to come! There are some things that we can predict, and perhaps adapt to. But there will also be some surprises because we can’t predict every last detail of what will happen. We’ve already set in motion some changes that we now can’t prevent from happening, but we need to prevent things getting worse.
- So, what does the future look like at the moment? This graph shows where we’re heading in terms of average temperature increases across the globe. Its important to remember that as the temperature goes up, then all those other effects get worse. So, looking at the top line of the graph [red], if we don’t take this problem seriously, and we all say ‘Pfft! Climate change. I don’t really care to be honest’, then we go along this ‘business as usual’ trajectory. We don’t change anything we’re doing and carry on as we are. This graph shows that we’ll end up with nearly 4 degreesC average temperature rise by 2100. And this would continue going up afterwards. Once we set it in motion, the effects last for a long time – thousands of years. This doesn’t sound like a lot, until you realise that the last glacial period – when most of the Northern hemisphere was completely covered in ice – was only about 6-8degrees colder than today. So this change is over half of that. And its in the opposite direction – hotter than any temperatures we (as human’s) have ever experienced. Okay, so thankfully, we have started taking this problem seriously. Governments around the world have stood up and said ‘We need to do something about this problem!’ and have gotten together and pledged to cut their greenhouse gas emissions to avert this future. Yes! Unfortunately, even with what we have pledged, we only change our future a small amount. In fact, with current global emissions pledges, we’re still heading along the second line here [purple]. Still a temperature change of about 3 degreesC – half of that glacial/interglacial temperature change.
- So, there’s this big gap between ‘what we’re doing’ to stop climate change, and ‘what needs to be done’. We call this the ‘physics-politics gap’ So, on the left here – the ‘politically realistic side’, we’ve got what politicians think is socially palatable to us in terms of emissions reductions – what they think they can manage and still be voted in the next election. We in the UK have pledged to cut our emissions by 80% by 2050. This is actually the strongest piece of climate change policy in the world! We have it in law that we have to do this – the Climate Change Act. No mean feat. But, still not enough. We find this only gets us part way across this gap, and we’re furiously trying to get to the other side, but never quite managing it. What we do in Zero Carbon Britain, is look at the other side of this gap – the ‘physically realistic side’. We ask, ‘what does it look like to actually rise to the challenge of climate change’, ‘according to the climate scientists, what does the UK need to do to play its part’, and moreover – ‘what does that look like?’ Then we will have a better idea of where we need to head, and how we might get there. And what we find from the climate science is that basically, we need to reduce our emissions to at least zero, as soon as possible!
- So, this is our challenge. And Zero Carbon Britain basically sets out a ‘technically robust scenario in which the UK has risen to this challenge’ We do all the sums about what would be necessary, based on current research and technology to see what is necessary to be on that other side of the gap.
- So this is where we start. Our emissions today are about 650 mega-tonnes of CO2 equivalent. That is basically, a lot. One kilo-tonne CO2e is about how much is emitted by flying the entire UK Olympic squad (that’s 541 athletes) around the world once. One mega-tonne is about a thousand times this. So, every year, we’re emitting the equivalent of flying our Olympic squad around the world 650 thousand times! Our energy processes – heating our homes, traveling around – our non-energy processes (industry, waste processing), and our land use (mainly agriculture) all give off greenhouse gases into the atmosphere, year on year [point to each bar]. Our land use also captures some carbon – taking it out if the atmosphere and storing it in plants and soils, but not a lot. This ‘carbon capture’ in no way balances out our emissions.
- Whereas in ZCB, we find we can reduce those emissions to near zero – though we can’t currently eliminate them totally. We can also increase the amount of carbon we capture, so that these two things do balance – making our net total zero. And we think we can keep this system running for about 100 years. Hopefully plenty of time to figure out how to get rid of those remaining emissions.
- So, we can get to net zero. And we also show that we can do this without nuclear power, or future technologies yet to be invented. We’re not relying on someone to come up with a magic idea some decades into the future, we only use what we’ve got at our disposal now. Which means, if we really wanted to, we could do it now. We also show that we can do this without major impacts on our quality of life – that is, we still have the vast majority of all the mod-cons we’ve got used to. In fact, we go even further than this and say, we think our future is better.
- Why do we say this? Well, what we’ve got to stop doing, is pretending that we can continue as we are, and that the future will be a carbon copy of today. Its just not true. No ‘business as usual’ future is actually available, because ‘business as usual’ behaviour-wise, means a vastly changed climate, which will mean massive changes to our lives in the future, whether we like it or not [red line]. So, what we say, is that if we make smaller, and planned changes now to help reduce climate change, then our lives in the future will be more like those we have today [green line]. Probably not identical, but similar.
- Also, from a very broad brush perspective, we think there will be benefits to our society that are beyond those related to preventing further climate change. Jobs – from building new infrastructure and changing how we do things. Adapting to some changes we know are coming even if we do act now. Help for other environmental problems. And an improvement in our personal health and wellbeing.
- So, how do we do this? What does our Zero Carbon Britain look like?
- Essentially, what I’m going to talk about is how we get from this …
- To this.
- But I’m also going to talk you through the answers to two big questions that we have been researching over the last year or so. Firstly, if we use renewable energy systems that don’t always produce the same amount of energy – when the wind doesn’t blow, or the sun doesn’t shine – and our energy demands go up and down, for example when we have a cold winter or we all switch the kettle on after Eastenders finishes, how do we ‘keep the lights on’ at all time? How do we make sure we have the right amount of energy, at the right times? Secondly, if we need to reduce our emissions from agriculture, and change our food and land use systems, can we produce a healthy balanced diet for the UK that is lower in greenhouse gases, and looks after our land?
- So, how does our energy system work in ZCB?
- If we briefly go back to this picture of current UK GHG emissions, we can see the scale of the challenge we are up against.
- That the majority of our emissions – about 82% - come from the way we produce and use energy.
- And this is the reason why. Most of our energy comes from fossil fuels [indicate to left hand stack on the image] – coal, oil and gas – that release carbon dioxide when we burn them to produce energy. There is a small amount from nuclear power [purple], and from biomass [green] – most of which currently comes from burning waste. There is a tiny sliver of our energy that is currently produced by wind [blue]. These produce a huge amount of energy that we use for heating, appliances (anything that you switch on and off), industry and transport [indicate to right hand stack on the image] – our energy demands. You can see here that we use most of this energy for heating our buildings [pink] and for moving ourselves and all our things around [blue]. Even though some energy gets lost in conversion processes [point to central stack], we still consume a huge amount of energy. If you think, one light bulb uses about 60 Watts of electricity, then a tera-watt is a trillion watts (or a million, million watts). And we use about 1750 of these tera-watts every year.
- So, lets first look at what we can do about our colossal our energy demands. If we use less energy, then we will need to supply (or produce) less energy in the first place, to cater for our demand.
- So, what we do, is we look at this demand, and ask “How much can we reduce this demand without dramatically changing the way we live?” The answer is that we can cut demand a massive amount – by about 60%. This is what we call the POWER DOWN. But, as you can see in this graph, this 60% cut isn’t uniform across all sectors – different reductions can be made in different places.
- For example, in our scenario, industrial energy demand isn’t cut very much at all. We change the kind of energy that is used – today industry uses a lot of gas and oil, in our scenario it is mostly electricity – but the amount does not change dramatically
- The reason for that is that we assume industrial output will actually increase compared to 2010. We say that we’ll probably produce roughly the amount of ‘stuff’ per person as we did before the recession (or economic crisis, or whatever you choose to call it). There will also be more of us in the future, and we’ll probably have some infrastructure we need to produce. So, our ‘output’ – how much stuff we make – will go up. At the same time, industrial processes will likely become more efficient – over recent years, industry in the UK has actually done a very good job at becoming more efficient. So, the energy intensity – the amount of energy needed for producing ‘stuff’ will go down. Overall, these two things roughly balance, meaning we need about the same amount of energy for industry in our scenario – only small energy savings here.
- It’s a very different picture when it comes to heating, where there are massive energy savings that we can make. Our energy demand for hot water will probably not change that much if we still all want to have showers and do the washing up – in fact, it might go up a bit seen as there are more of us. But in terms of heating our homes, offices and other buildings, we can do loads to save on energy – mainly because we have such a terrible stock of buildings in the UK. Most of Europe laugh at the state of our housing – why do we still have un-insulated lofts, and single-glazed windows? In fact, this part of our scenario, if anything, is quite dull – we’ve known about this stuff for ages. All we need to do to make energy savings is to get on and do it!
- What we need to do is to build any new houses to a good standard – not quite PassivHaus, but near it. Then we need to insulate our existing buildings properly and reduce draughts. Simple. The last amount of energy savings come from having better temperature controls – the techy part. If we’re not using a room, why heat it? I’m not saying we all have to remember to manually turn the heater off when we go out of a room, and then turn another on when we go into a different one, like you would with lights. We can actually use smart temperature control of our spaces that do these kinds of things automatically. And finally, yes, we do suggest putting a jumper on instead of turning the heating up – where appropriate. Not such a high-tech solution, but effective none the less. So, in total, these measures can save us up to 60% of the energy we use to heat our buildings.
- But perhaps the largest energy saving potential is from transport. Which is amazing seen as our politicians seem not too keen to talk about energy savings in transport – you won’t hear much about it in the news. A third of our total energy demand comes from transport, and we can get that energy demand right down. How do we do this – do we just ask people to travel less?
- Well, in part – yes. In our scenario, we distance we travel in a year is reduced by about 15%. We have things like skype and tele-conferencing that could be used more effectively than they are now. We could also make more journeys by foot and by bike. A large proportion of our journeys are very short distance, so if we made our cities more foot- and cycle-friendly, we could encourage people to make them by different means. A better public transport infrastructure would also help people get around more by bus and train, so in our scenario, these forms of transport are increased. There is less personal travel by car, but still a significant proportion of our journeys are made in this way – on average.
- These changes alone, fewer miles and better modes of transport, make a big difference to how much energy we use for transport – about a 30% reduction in energy demand [indicate to transition from first bar on the left, to the central bar]. You’ll also notice here that air transport is reduced [indicate to pink area of first two bars]. We say that we can make domestic journeys by rail or coach; and that we have to reduce international aviation by two-thirds. But since about 6-7,000 flights come in and out of the UK every single day, this doesn’t mean that we wouldn’t be able to go abroad. We might also choose to use train links to Europe – for example the channel tunnel for continental travel, and we’d still be able to go on holiday further afield, though perhaps less frequently than we’ve gotten used to. This final chunk [indicate transition from central bar to right hand bar] is one of my favourite parts of our energy reduction – its basically free energy. All we have to do to get our energy demand from transport from this [central bar], all the way down to here [right hand bar], is basically electrify all the bits of transport that we can. That’s it! This is because an electric car, for example, in comparison to a regular petrol or diesel car, will go about 3-4 times as far using the same amount of energy – so we get more miles for the same amount of energy. Okay, so it’s a big job, but it seems like a no-brainer. Together, these changes mean that our energy demand from transport can be reduced by about 80% - a massive saving.
- So, this, together with some efficiency improvements in our appliances, is how we ‘Power Down’ our energy demand by about 60%. But we still consume a huge amount of energy – about 600 tera-watts, or 10 trillion (million million) light-bulbs-worth. So, lets look at where we can get that energy from – we call this POWER UP.
- Well, thankfully, we live in a very windy place! You can see form this picture that we have the best wind resource in Europe. In fact, we have one of the best wind resources in the world. When you consider that currently, Germany and France [indicate on graph – area of ‘low wind speeds’] produce more energy from wind than we do, despite being not very windy places, then it seems ridiculous that we’re not using our resource better.
- And this is exactly what we propose – using our natural resources better, and playing to our strengths. This is the energy flow diagram that shows how we get our energy, and where it goes. On the right hand side [indicate each], we have all the reduced energy demands we’ve just talked about – heating, appliances (things we switch on and off), industry, and transport. On the left hand side, we’ve got how we produce our energy in our scenario – our renewable energy supplies. Basically, what we did was to look at all sorts of reports, studies and data sources that show ‘how much energy could be produced in the UK from each renewable resource’. So we’ve looked at how many offshore wind farms we can build, what percentage of all UK roofs we can cover in solar panels, how much wave and tidal power we can realistically harvest, to make sure that we meet the demand. And we end up with a suite of resources which we can power the UK with. In fact, there is plenty of energy out there – more than we need. But because of our luck in being in such a windy location, then a large proportion does come from wind – both onshore and offshore. Together, these produce about half of our energy. The remaining energy comes from all sorts of renewable sources, including a significant, and very important role for biomass energy [You can choose to list a few from the diagram]. And through a number of conversion processes and energy transfers, we can make sure that we are supplying enough energy to meet demand.
- So, this is how our new energy system looks. We’ve reduced our demand [indicate right hand bar], which means, despite there still being losses in the system [indicate middle bar], overall we need to supply less energy in total [indicate left hand bar] – all of which can be produced using renewable resources. This isn’t totally new, and different researchers have come to very similar conclusions.
- But the big question always is: Can we keep the lights on? With so much energy in the form of electricity from fluctuating, variable sources like wind and sun, how do we make sure that supply always meets demand? What do we do on a day when the wind doesn’t blow and the sun doesn’t shine?
- Well, to answer this question, we have constructed the ZCB Energy Model. And what we’ve basically done is, we’ve taken the last ten years, 2002 to 2011 inclusive, and we’ve asked the question: “With the assumptions we make in our scenario – about how many wind farms there are, about how much heat our buildings need etc – how would things have worked out from hour to hour under the conditions experienced 2002 to 2011?” So we have collected hourly data on wind speeds and solar radiation and wave heights and temperatures and electricity demand and so on for every one of almost 88,000 hours for these ten years to simulate how our scenario would perform.
- For example, say we had put two wind farms in these locations [indicate two squares offshore]. Using data from NASA on wind speeds, we can use our model to see at how much energy they would have produced, hour-by-hour over the last 10 years [indicate to wiggly lines on right hand panel].
- And we can do that for any offshore location we choose. And use a similar approach to all the rest of our renewable energy supplies…
- For onshore wind. And for solar and wave and tidal and so on, using hourly data on tides and sunshine for example. Using a wide range of data sources, we can build up a picture of how much energy we would have produced every hour over that 10 year period under our scenario’s energy supplies.
- And then we went and did the same for energy demand. Based on past electricity demand data from National Grid, on temperature data from the Met Office, and typical patterns for when we charge electric cars or run industrial processes and so on, we’ve build a hourly model for energy demand, again for all the 88,000 hours over that 10 year period. And then we put them together…
- And unsurprisingly, they don’t match up [indicate right hand graph]. There are times of shortfall – when we don’t produce enough energy to meet our demands [indicate pink areas on right hand graph], and there are times of surplus – when we produce far more than we need [indicate blue areas on right hand graph] This isn’t really a surprise – wouldn’t it be amazing if there was a massive gust of wind just as everyone turned on their kettles after Eastenders! Unfortunately, it doesn’t happen like that. Now, there are two ways in which people normally deal with this problem. One is that they say ‘well, if we use all sorts of different resources, and we spread them out across the country, then they’ll all produce different amounts of energy at different times, and hopefully it’ll all even out.’ Unfortunately though, we find that even if we spread out our solar panels and wind farms all over the UK, we still have some very dramatic fluctuations in supply, and problems meeting demand at times. The other solution that people talk about goes along the lines of ‘well, when we have a surplus of electricity, we can sell it to Europe, and then buy some back when we have a shortfall, and hopefully we’ll make a nice tidy profit as well!’ And, although there is perhaps some mileage here, unfortunately the thing that scuppers this plan is that weather systems tend to be quite big. Generally, when its not windy here, its not only not windy almost everywhere in the UK, but its also not windy in the rest of Northern Europe. We also have to think about whether or not that guarantees our supply will meet demand – if our systems fluctuate, then so will everyone else’s, and weather patterns, though predictable to a certain extent, as still quite chaotic. We can’t guarantee that Spain would produce enough energy from solar at exactly the same time that the UK’s wind speeds dropped. But the good news is that we have found a reliable way of securing that our energy supply meets our demand!
- And this is what it looks like! [Working from the left hand side of the image] So, we still have a surplus of electricity that we don’t need [indicate to export], which could be exported if necessary; but we can use part of our surplus electricity [indicate to blue arrow going into ‘electrolysis’] – produced when supply exceeds demand – in a clever way to cater for our shortfalls. The electricity is used in ‘electrolysis’ to split water – H2O – into its ‘H’s and ‘O’s. The ‘O’s can just go into the atmosphere, or may be useful in some industrial processes, but the ‘H’s are what we need – the ‘hydrogens’. [Now working from the top right of the diagram] These ‘hydrogens’, get combined with ‘carbons’ from biomass [indicate ‘biomass’ stream from the top]. Carbon is the basic building block of life – a good portion of you and I are made out of carbon, and even more of plants are (they take it in as carbon dioxide from the atmosphere when they grow). Two chemical processes [indicate two grey boxes – ‘sabatier’ and ‘FT’], combine these ‘hydrogens’ and ‘carbons’ to create synthetic liquid fuels [purple stream] and synthetic gas [light green stream]. These fuels are chemically very similar to their fossil fuel counterparts – oil and natural gas, but are ‘carbon neutral’ – don’t emit greenhouse gases on net – as long as we use renewably produced electricity and sustainably sources biomass. Now, most of these carbon neutral synthetic fuels go to cater for some demands that can’t be met with electricity – some industrial demands [indicate ‘industry’], and some transport demands [indicate ‘transport’]. For example, we can’t fly planes on electricity – we need a fuel more like that we use today. A very small amount of carbon neutral synthetic gas goes into ‘back up power stations’ [indicate grey box]. These power stations are much like the gas power stations we have today (since the gas is almost the same as natural gas), except that they can be turned on and off very quickly, and are ‘idle’ a lot of the time because we don’t need them constantly. Gas power stations like this already exist in some places – though largely they have been built because they are economically cheaper in some markets. Then, we turn these power stations on as and when we need them, producing electricity to cater for demand when we have a shortfall. Amazingly, only 3% of our electricity is produced this way over the course of an average year, and we turn these power station on only about 15% of the time – the remaining 85% of the time, our renewable resources cater for demand. But this process is crucial in making sure we still have power during those times – that we can ‘keep the lights on’. But this system requires a significant portion of biomass. We can’t just rely on waste streams – or we’re encouraging the waste to be made, so we need land to grow the biomass we need.
- Which is where the land use model for Zero Carbon Britain comes in.
- If we just briefly return to that graph representing UK emissions, and start looking at the effect our scenario has had so far …
- We can see that we have all but eliminated emissions from energy processes. We know we can also reduce emissions from industrial and waste processes (these non-energy emissions [indicate red bar] – to a degree, but not completely if we’re adhering to our ‘only technology available now’ rule.
- But our land use – mainly agricultural processes still emit greenhouse gases. On the other side of the picture [indicate dark green part on left hand side], there is some natural processes that lock up of carbon – that capture it from the atmosphere and store it in soils, trees and other plants. But we’re still a bit away from balancing out the amount of carbon we ‘capture’ with what we ‘emit’ – there are still some net emissions [indicate to grey total]. So, we need to go further to become net zero carbon. Our land use is they key to this.
- And this is where those emissions come from. These two charts show where emissions from agriculture come from. I have included the pie on the left – World agricultural Emissions – because we import so much of our food currently. Looking at UK agricultural emissions [chart on right], we can see that a large portion of emissions come from using fertiliser on soils – both on cropland and for grazing grassland. Some of this fertiliser isn’t used by plants, and is released into the atmosphere at nitrogen oxide [indicate yellow portion, ‘N2O’]. Another point to note is the large proportion that comes directly from livestock – almost 60% of those emissions. Note this is all livestock, not just cows as depicted here – we mean cows, sheep, chickens and pigs. Finally, there are some emissions from ‘land conversion’ – not much in the UK [indicate light green portion in UK], but on a global level this is a massive contribution [indicate same on lift hand side pie chart]. This is because we have already converted most of our land to agriculture, so we don’t have much left to convert! But we have to admit we are probably contributing to the massive emissions from converting rainforest, woodlands and other habitats to agriculture elsewhere in the world. This of course, also has massive impacts on biodiversity.
- If we look at our land use today, as we did with our energy use, we can see where the problems, and opportunities lie. Loosely speaking, this part is responsible for most of the carbon captured – taken out of the atmosphere – today, although some non-intensively grazed grassland also helps. Only about 12% of our land is covered in forest [indicate 3 green blocks in top right hand corner] – most of which is harvested for wood. Despite this we import about 85% of the wood we use today. At the moment, we use most of our land for agriculture, for producing food, about 85% of which is used for livestock. Despite this, we import about 42% of the food we eat. Most of this is grazing land for cows and sheep – producing beef, lamb and dairy products, but about half of our cropland is also used for livestock – for growing feed for them to eat. Only half our cropland is used to grow food for us. Right, so. Thats the picture of our land use today. Given that we use so much land for food production – here and elsewhere in the world, what kind of diet do we have?
- The answer is not great. In fact, these statistics show that our diets here in the UK are actually have a bad effect on us. And this is largely because we: Eat too much food and the wrong balance of foods. Looking at the diagram on the right, the central circle shows us what we should be eating – the recommended portions of ‘starchy foods’ (potatoes, bread, cereals etc) [yellow]; high protein foods (meat, dairy, lentils, nuts, beans) [pink]; foods high in saturated fats, salts and sugars – HFSS foods (cake, biscuits, fried food) [purple]; and fruit and veg (self explanatory!) [green]. The outer circle shows the proportions of what we actually eat and drink today in the UK. Too many foods high in saturated fats, salts and sugars; more high protein foods than we need, and we completely under-eat starchy foods and fruit and veg. You can understand why the government are so keen on the ‘5-a-day’ message now! Finally, we waste a lot of food. Whilst this doesn’t have an impact on our diet, it does mean we put unnecessary pressure on our food production systems – on our agriculture. And it contributes to the greenhouse gas emissions from agriculture as a result. This figure – 30% is the amount of food produced in Europe that is wasted. About half of this we waste in our homes – I am also guilty of leaving things in the fridge too long and ending up throwing them away; but half is wasted along the supply chain. Most of this food is fit for eating. It might be, for example, that supermarkets are only willing to buy apples that ‘look nice’ so that we’ll buy them. All the ones that are a bit wonky, or are too big or too small are thrown away. Just look at how regular all the fruit and veg in the supermarket is next time you go – do you think everything naturally grows the same size and shape?
- So, lets address this question first. Can we provide a healthy, balanced diet for ourselves, that’s low in greenhouse gas emissions?
- So what we do, is to construct a food and diets model. We take about 60 different foods from the National Diet and Nutrition Survey, and look at the emissions associated with producing them, the land they require, and various nutritional qualities. Here, for example we have a few different protein sources. Each represents one daily ‘portion’ of protein. So, we can look at the nutritional quality of each source – the score at the top [indicate NPS] shows us a very basic measure of ‘how healthy it is’. The score actually runs from about -9 to +25, where negative numbers are most healthy, and positive numbers are least healthy. So, here all our protein sources are pretty healthy, although the ‘meat alternatives – quorn, soya etc) are ‘best’. There is, however a massive difference in the greenhouse gas emissions from each – with livestock producing the largest emissions, and nuts and seeds the smallest. Generally, meat and dairy – or ‘animal based protein’ produces much more emissions than any ‘plant-based’ protein sources. With respect to land use, then grazing animals, most obviously use the most land because of all that grazing grassland they need.
- This is an example, which demonstrates the difference in GHG emissions and land use that dietary choices can make. We’ve highlighted this one because most of those emissions come from livestock, and as yet there are no ‘techno-fixes’ for livestock [I sometimes talk here about the ‘lab burger’ that was recently created – a good 10 years worth of research for one burger! Not something we think is really ready to be rolled out to cater for the UK meat demand!]. So we have to find other ways of reducing greenhouse gases. And this model allows us to, in effect, design a diet that is healthy and balanced, low in greenhouse gas emissions – reducing those agricultural emissions, and only uses the agricultural land we have already in the UK.
- We can use the one techno-fix we have – applying nitrogen fertilisers to the soil reduces those nitrogen oxide emissions somewhat. We can also reduce how much food we waste. We can only eat what we need – which would seem to make sense. But the main thing that we can do is ‘product switch’ – change what it is that we eat. Now, some of this we need to do anyway from a nutritional perspective – to make sure we have a healthy, balanced diet. For example, eating more fruit and veg [indicate green bars], more starchy foods [indicate yellow bars], and far less foods high in saturated fats, salts and sugars [indicate purple bars], and a bit less from the ‘high protein’ category [indicate pink bars].
- That helps us restore our ‘food group balance.’
- But there are changes within the ‘high protein’ category that are done to reduce greenhouse gas emissions, and land use. We significantly reduce the amount of beef and lamb products in the average UK diet – by about 90%. Pig, chicken, eggs and dairy products are also reduced – by about 60%. To compensate, the amount of plant-based protein sources are increased – meat and milk alternatives, beans nuts and seeds. Its important to note here, that by far the easiest way of reducing greenhouse gases in agriculture is for us all to not eat red meat or dairy, but we’re compromising here since currently only about 2% of the UK is vegetarian or vegan! Despite these changes, our average diet in the UK every week would have in it: 5-6 portions of meat/dairy or eggs, 4 portions of meat alternatives (beans, quorn or whatever), and enough ‘real’ milk for tea, coffee and breakfast cereal. A compromise, perhaps …
- But one that allows us to reduce the greenhouse gas emissions from agriculture. And reduces the amount of land we need to produce food. About a quarter of grazing land is needed, and more cropland is used to provide food for us rather than our animals. Despite reductions in meat and dairy products, still over half of agricultural land in the UK is dedicated to livestock in some way. And even though we use less land in the UK, we ca n reduce our imported food from 42% to 17%. Those are mainly things we cannot grow in the UK (e.g. cocoa beans). We don’t import any livestock products or feed for livestock, as these have most negative impacts elsewhere in the world. And it is basically this ‘freed up’ grazing land that makes the rest of the ZCB scenario fit together.
- It means we can re-purpose this land. We can provide the biomass that is required for our energy system. We use second generation energy crops (‘woody’ plants – coppice, wood and grasses) that are suited to the land, to provide for different energy system needs. We don’t need to import any biomass which means that we can keep its production sustainable and carbon-neutral.
- And finally, we can use some of the land we already have, and the final portion of grassland to increase the amount of carbon we ‘capture’ from the atmosphere. And we can use only methods that are safe and proven to work and will continue to work for at least 100 years. We restore a portion of peatland in the UK [indicate blue area]. Peatland is very carbon-rich soil which can capture carbon for hundreds of thousands of years – in fact. It’s the first step of re-making those fossil fuels we’ve been burning! At the moment, we’ve degraded peatland in the UK to the point that its emitting carbon. By restoring it, we can turn this around and make our peatland capture carbon. And we can extend the forested areas we have which are already capturing carbon [indicate increased green areas], and at the same time increase the use of UK timber for wood products. There are also benefits for biodiversity from restored peatlands (very precious habitats) and more ‘unharvested forest’. Forests also increase our resilience against climate change we already know to be in the pipeline – providing flood protection, cooling, stronger ecosystems.
- So, in ZCB we have moved from land use that looks like the diagram above, to the one shown in the diagram below.
- We can actually provide almost everything we need on UK land, despite having a relatively small area compared to our population. We end up with about a 1/3 dedicated to food production; 1/3 dedicated to carbon capture; and about 17% dedicated to energy/fuel.
- So, once we’ve put all of this together….
- We can see how we get from this ..
- To this. We have reduced our emissions as far as current technology allows us – making some compromises along the way, but keeping roughly the same standard of living to which we’ve become accustomed. We might fly less, and eat less meat; but we have a healthy, balanced diet, warm homes, and we still visit friends and family. And most importantly, we can get to net zero emissions.
- We can provide a reliable energy system that ‘keeps the lights on’
- And we can provide a diet that is healthier than today’s, and that is lower in greenhouse gas emissions.
- An initial analysis shows that, in this future, there are benefits ‘beyond carbon’ in more than rising to the challenge of climate change. We’ve created job for the UK, we’ve helped adapt to the changes in climate we expect, we’ve improved the outlook for biodiversity which is having a really hard time of things at the moment, and we’ve improved our health and wellbeing as individuals and as a society. Moreover, it’s a positive future.
- Thanks! [Q+A – either by skype, or DIY, or suggest people get in touch with us if there is something you can’t answer.]