Chapter 8
Solutions
Introduction
There are three types of solutions to climate change. The first is adaptation, which is providing protection for the population from the impacts of climate change. The second is mitigation, which in its simplest terms is reducing our carbon footprint and thus reversing the trend of ever-increasing GHG emissions. Third is geoengineering, which involves large-scale extraction of CO2 from the atmosphere or modification of the global climate.
Adaptation
There have already been climate change impacts, and these will increase as the global temperature continues to rise. The second report of the IPCC Sixth Assessment examines the impacts of climate change and the potential sensitivity, adaptability, and vulnerability of each national environment and socioeconomic system. The IPCC gives six clear reasons why we must adapt to climate change: (1) climate change impacts cannot be avoided even if emissions are cut rapidly to zero (see Chapter 4); (2) anticipatory and precautionary adaptation is more effective and less costly than forced last-minute emergency fixes; (3) climate change may be more rapid and more pronounced than current estimates suggest, and unexpected and extreme events are likely to occur; (4) immediate benefits can be gained from better adaptation to climate variability and extreme atmospheric events (e.g. with the storm risks, strict building laws and better evacuation practices would need to be implemented); (5) immediate benefits can also be gained by removing maladaptive policies and practices (e.g. building on floodplains and vulnerable coastlines); and (6) climate change brings opportunities as well as threats. Figure 37 provides an example of how countries can adapt to the predicted sea-level rise.
37. Model response strategies for future sea-level rise.
The major threat from climate change is its unpredictability (see Chapter 6). As noted earlier, humans can live within a huge range of climates, from baking deserts to the frozen Arctic, but we have only been able to do so because we have been able to predict the extremes of weather we must cope with. As climate change impacts increase then the weather will become both more extreme and more unpredictable. So both physical and social adaptations are required to protect people’s lives and livelihoods.
Physical adaptations require us to think about how to change our infrastructure. For example, will we need to build better sea defences, more reservoirs, restore wetlands, or retrofit buildings with air conditioning? In many countries, these large infrastructure projects can take up to 30 years to plan, develop, and build. If we take the issue of sea-level rise (Figure 38), it can take 10 years to research and plan appropriate measures to cope with it. It can then take another 10 years for the full consultative and legal processes; and a further 10 years to implement these changes. It can take another decade for the natural restoration to take place to complete the sea-level adaptation project (Figure 38). A good example of this is the Thames Barrier that currently protects London from flooding: it was developed in response to the severe flooding in 1953 but did not open officially until 1984, 31 years later.
38. Lead times for response strategies to combat climate change.
We must also consider social adaptations and changes in people’s behaviour. After the 2003 European heatwave, France completely reassessed its health response to the crisis. They changed everything, including: communication with the public; vulnerable individuals’ health checks; local health responses; and hospital admissions and treatment. It is estimated that in subsequent heatwaves the death toll was cut by over 75% because of these social adaptations. In many countries food and water security will be the major issue, and therefore policies to safeguard people’s access to food and clean water even when they are unable to pay for it will be essential. In many ways the most important adaptation to climate change is good governance, so that policies can be formulated and enacted to protect the most vulnerable people in society.
There are, however, limits to adaptation. In some regions, climate change impacts may become so great that they go beyond our ability or finances to protect the population living there. Continued sea-level rise will mean many small island nations may become uninhabitable and the population will have to relocate. In 2019, Indonesia’s President Joko Widodo announced that the national capital would move from Jakarta, on the island of Java, to the province of East Kalimantan, on Borneo. This was in part to relieve pressure on the capital and address inequality in Indonesia, but it was also because Jakarta is sinking. Areas of north Jakarta, even with the sea wall designed to protect the population, are falling at an estimated 25 cm a year due to subsidence. This is due to sea-level rise and the extraction of fresh water from shallow aquifers, leading to subsidence.
The other problem is that adaptation requires money to be invested now; but many countries just do not have that money and, where they might raise it, their citizens are unwilling to pay more taxes towards protecting themselves in the future, since most people live for the present. Many countries have short election cycles of four to five years, which means politicians are always thinking about the short term and rarely about the longer term, and this limits their insight into and investment in adaptation projects. This is, of course, despite the fact that all of the adaptations discussed will in the long term save money for the local area, the country, and the world.
Mitigation
The requirement to cut global carbon emissions by half by 2030 and hit net zero by 2050 is extremely challenging, and will mean using every available solution as soon as possible. There is some good news. GDP growth and carbon emissions have over the past decade become completely decoupled, with a large rise in world GDP compared with a much smaller rise in carbon emissions (see Figure 39). What we need to do now is to invert the relationship so that as GDP rises, carbon emissions drop. In 2020, the International Energy Agency (IEA) and International Monetary Fund (IMF) published a report recommending massive investment into clean energy, which would create millions of new jobs. It was realized during the Covid-19 pandemic, that energy generation and use were the key to dropping carbon emissions. The report outlines plans for mass home renovations, fossil-fuel subsidy reforms, expansion of renewable energy, and power grids. Several of these are discussed below.
39. Comparison of GDP and carbon-emission growth since 1971.
Alternative, renewable, or clean energy
Fossil fuels were an amazing discovery, and they have allowed the world to develop at a faster rate than it has at any other time in history. The high standard of living in the developed world is based on cheap and relatively safe fossil fuels. But burning fossil fuels has had the unintended consequence of changing global climate. So in the 21st century we need to switch from fossil-fuel energy to low-carbon or carbon-neutral energy. This includes solar, bio, wind, hydro, wave, and tidal energy.
Solar power. The Earth receives on average 343 W/m2 from the Sun, and yet as a whole the planet only receives two-billionth of all the energy put out by the Sun. The Sun is the ultimate source of energy, which plants have been utilizing for billions of years. At the moment, we can convert solar energy directly to heat or electricity, and we can capture the energy through photosynthesis by growing biofuels. The simplest approach is through solar heating. On a small scale, houses and other buildings in sunny countries can have solar heating panels on the roof, which heat up water, so people can have carbon-free hot showers and baths. On a large scale, parabolic mirrors are used to focus the solar energy to generate hot liquid (water or oil) to drive turbines to create electricity. The best places to situate solar heat plants are in low-latitude deserts, which have very few cloudy days per year. Solar heat plants have been built in California since the 1980s and are now being built in many other countries. Solar photovoltaic panels convert sunlight directly into electricity. The individual rays of the Sun hit the solar panel and dislodge electrons inside it, creating an electrical current. The main advantage of solar panels is that you can place them where the energy is needed and avoid the complicated infrastructure normally required to move electricity around. Over the past decade there has been a massive increase in their efficiency, the best commercially available solar panels being about 23% efficient, which is significantly more than photosynthesis at about 1%. Solar panel efficiency goes up during winters, as they work better in cold temperatures, although, of course, then they also produce less electricity due to the shorter days and less intense sunlight. There has also been a significant drop in price due to huge investment in the technology.
Biofuels. These are the product of solar energy converted into plant biomass via photosynthesis, which can then be used to produce liquid or solid fuels. The global economy is based on the use of liquid fossil fuels, particularly in the transport sector. So, in the short term, fuels derived from plants could be an intermediate low-carbon way of powering cars, ships, and aeroplanes. Ultimately, electric cars are the future, because the required electricity can be produced carbon-neutrally. However, this energy source is not an option for aeroplanes. Traditional air fuel, ‘kerosene’, combines relatively low weight with high energy output. Research is being carried out to see whether a biofuel can be produced that is light enough and powerful enough to replace kerosene. Many power stations around the world have been converted so that they can burn wood pellets instead of coal or natural gas to create steam to turn the turbines to make electricity. Critics have argued that wood pellets are not sustainable and do not have as low a carbon footprint as claimed.
Wind power. Wind turbines are an efficient means of generating electricity, if they are large and preferably located out at sea. Ideally, we need turbines the size of the Statue of Liberty for maximum effectiveness. The London Array has been built in the River Thames estuary, 12 miles from the Kent coast, and consists of 175 turbines. It will generate over 2,500 megawatts (MW), making it the world’s largest offshore wind farm. It can power up to half a million homes and reduce harmful CO2 emissions by nearly 1 million tonnes per year. There are some problems with wind turbines. First, they do not supply a constant source of electricity; if the wind does not blow or it blows too hard, no electricity is generated. Second, people do not like them, finding them ugly, noisy, and a worry in terms of the effects they may have on local natural habitats. All these problems are easy to overcome by situating wind farms in remote locations, out at sea, and away from areas of special scientific or natural interest. Recent research has shown little or no effect on local wildlife even when wind turbines are situated close to land. One study suggests that wind in principle could globally generate over 125,000 terawatt-hours, which is five times the current global electricity requirement.
Wave and tidal power. Wave and tidal power could also be an important source of energy in the future. The concept is simple: to convert the continuous movement of the ocean in the form of waves into electricity. However, this is easier said than done, and experts in the field suggest that wave power technology is 20 years behind solar panel technology. Tidal power has one key advantage over solar and wind power—it is constant. In any country, for energy supply to be maintained at a constant level, there has to be at least 20% production guaranteed, known as the baseline requirement. With the switch to alternative energy, new sources of energy to provide this consistent baseline need to be developed.
Hydroenergy. Hydroelectric power is globally an important source of energy: in 2010, it supplied 5% of the world’s energy. The majority of the electricity comes from large dam projects. These projects can present major ethical problems as large areas of land must be flooded above the dam, requiring the mass relocation of people and destruction of the local environment. A dam also slows water flowing down a river and prevents nutrient-rich silt from being deposited lower down. If the river crosses national boundaries, there are potential issues over the rights to water and silt. For example, one of the reasons why Bangladesh is sinking is the lack of silts due to the dams built on the major rivers in India. There is also debate about how much GHG emissions hydroelectric plants save, because even though the production of electricity does not cause any carbon emissions, the rotting vegetation in the area flooded behind the dam does give off significant amounts of CH4.
Geothermal energy. Below our feet, deep within the Earth, is hot molten rock. In some locations, for example in Iceland and Kenya, this hot rock comes very close to the Earth’s surface and can be used to heat water to make steam. This is an excellent carbon-free source of energy, because part of the electricity generated from the steam is used to pump the water down to the hot rocks. Unfortunately, its availability is limited by geography. There is, however, another way the warmth of the Earth can be used. All new buildings could have a borehole below them with ground-sourced heat pumps. Cold water can then be pumped down into these boreholes, with the ground warming the water up, cutting the cost of providing hot water to buildings. This method could be used almost everywhere in the world.
Nuclear fission. Energy is generated when heavy atoms such as uranium are split—a process known as nuclear fission. The process has a very low direct carbon signature, but a significant amount of carbon is generated in mining the uranium, building the nuclear power station, decommissioning the power station, and safely storing and disposing of nuclear waste. At the moment, 5% of global energy is generated by nuclear power. The new generation of nuclear power stations are extremely efficient, achieving nearly 90% of the theoretically possible energy production. The main disadvantages of nuclear power are the generation of high-level radioactive waste and concerns about safety, although improvements in efficiency have reduced the waste levels and the new generations of nuclear reactors have state-of-the-art safety features built in. The 1986 Chernobyl disaster and the 2011 Fukushima Daiichi nuclear disaster illustrate that nuclear plants are, however, still not safe, being vulnerable to human error and natural hazards. The advantages of nuclear power, however, are that it is reliable and can provide the required base load in the energy mix, and the technology for its use is already available and thoroughly tested.
Nuclear fusion. This process involves the generation of energy when the nuclei of two small atoms fuse together. It is the process that lights up our Sun and every other star. The idea is that the heavy form of hydrogen found in seawater, deuterium, can be combined with the other heavy isotope of hydrogen, tritium; and the only waste product is the non-radioactive gas, helium. The problem, of course, is persuading those nuclei to fuse. In the Sun, fusion occurs in the core, at incredibly high temperatures and pressures. Great advances in fusion technology have been made around the world but what is required now is huge investment to make fusion commercially viable.
Carbon capture and storage
Removal of CO2 during industrial processes can be tricky and costly, because not only does the gas need to be removed, but it must be stored somewhere as well. The IPCC Special Report on Carbon Dioxide Capture and Storage published in 2005 concluded that the technology for carbon capture and storage (CCS) existed but that there is little commercial experience in configuring all of the components needed to create fully integrated CCS systems at the kinds of scales needed in the future. Power production costs that include CCS would rise by at least 15% and could be as high as 100%. Not all the recovered CO2 has to be stored; some may be utilized in enhanced oil recovery, the food industry, chemical manufacturing (producing soda ash, urea, and methanol), and the metal-processing industries. CO2 can also be applied to the production of construction material, solvents, cleaning compounds, and packaging, and in waste-water treatment. In reality, most of the CO2 captured from industrial processes would have to be stored. It has been estimated that theoretically two-thirds of the CO2 formed from the combustion of the world’s total oil and gas reserves could be stored in corresponding reservoirs. Other estimates indicate storage of 90–400 Gt in natural gas fields alone and another 90 Gt in aquifers.
Oceans could also be used to dispose of the CO2. Suggestions have included storage by hydrate dumping: mixing CO2 and water at high pressure and low temperatures creates a solid, or hydrate, which is heavier than the surrounding water and thus drops to the bottom (see Figure 32). Another more recent suggestion is to inject the CO2 half a mile deep into shattered volcanic rocks in between giant lava flows. The CO2 will react with the water percolating through the rocks. The acidified water will dissolve metals in the rocks, mainly calcium and aluminium. Once it forms calcium bicarbonate (HCO3−) with the calcium, it can no longer bubble out and escape. If it does escape into the ocean, then HCO3− is relatively harmless. With ocean storage there is the added complication that the oceans circulate, so whatever CO2 is dumped, some of it will eventually return. Moreover, scientists are very uncertain about the effects of this solution on the ocean ecosystems.
The major problem with all these methods of storage is safety. CO2 is a very dangerous gas because it is heavier than air and can cause suffocation. This was powerfully illustrated in 1986, when a large release of CO2 from Lake Nyos, in the west of Cameroon, killed more than 1,700 people and livestock up to 25 km away. Although similar disasters had previously occurred, never had so many people and animals been asphyxiated on such a scale in a single brief event. Scientists now believe that dissolved CO2 from the nearby volcano had seeped into the lake from springs below and had lain trapped in deep water by the weight of water above. In 1986, there was an avalanche that churned up the lake waters, resulting in an overturn of the whole lake and an explosive release of all the trapped CO2. Nevertheless, huge amounts of mined ancient CO2 is pumped around the USA to enhance oil recovery, and there have been no reports of any major incidents. Engineers working on these pipelines feel they are much safer than gas and oil pipelines, many of which run across most major US cities.
Transport
One of the greatest challenges to mitigating GHG emissions is transport. At the moment, transport accounts for 14% of GHG emissions globally. In many developed countries the carbon emissions from energy production, business, and residential sectors are all going down despite annual growth in the economy; but transport emissions, mainly from cars and aviation, are still increasing. Many in the developing world aspire to the same level of car ownership and international travel as the developed world and hence there is the potential for huge growth in transport emissions.
Electric cars, both in terms of range and performance, have improved greatly over the past decade and there is general acceptance that they represent the future. This acceptance has been accelerated by the 2020 pandemic, during which, in many regions, road traffic almost ceased due to lockdowns and everyone noticed the huge improvement in air quality. If there were a switch to 100% electric vehicles, there would be a 50% cut in air pollution. The constant wearing down of tyres, brake pads, and the tarmac on roads also creates air pollution, which accounts for the other 50%. The impact of electric cars on carbon emissions could be significant, but it would rely on there being a guaranteed supply of low-carbon or carbon-neutral electricity. In the UK from 2034 only electric cars will be sold and fossil-fuel engines will be banned by 2040, while in California all new passenger vehicles sold from 2035 onwards must be zero emission.
International shipping and aviation account for 3.2% of global GHG emissions per year. Aeroplanes have become an easy target for climate change campaigners as international flights are a highly visible symbol of consumption and have never been covered by an international treaty. There is a need for incentives to improve the carbon efficiency of flights and ultimately to make them as close to carbon neutral as possible. The fundamental issue is that currently an international treaty prohibits the taxation of aviation fuel. The Convention on International Civil Aviation, also known as the Chicago Convention, was signed in 1944 and has been revised eight times. It deals with the rules and regulations required to allow flights between countries. It also states that fuel, oil, spare parts, regular equipment, and aircraft stores are exempted from any form of taxation, which means a carbon tax on aviation fuel to drive efficiency gains is currently not permitted. This is unfortunate, as not only can we build much more efficient aeroplanes today, but there are alternative fuels that could be used. Biofuels could be developed as an additive or even as a replacement for traditional air fuel kerosene. It is also possible to create artificial kerosene, by extracting CO2 from the atmosphere and combining it with water. This takes a huge amount of energy, but if electricity from renewable sources were used, it could be possible to have carbon negative aviation fuel. This would still only work if there were regulations or a carbon tax in place to make it cost effective to create artificial kerosene. In the short term, as there is no real fuel solution for aviation, the airlines are keen to be involved in carbon trading. This way, the airlines can ‘offset’ their carbon emissions by ensuring an equivalent amount is saved elsewhere.
The other alternative is to persuade people to use public transport instead of their car or flying. For most people it is clear that providing cheap and accessible electric buses, taxis, subway systems, and railways would all help reduce the number of car journeys being made. Public transport could also help with freight and goods deliveries, as the railway network could be used at night to transport goods around the country and between countries. Railways could also be used to replace internal and international flights. It has been calculated that all internal flights between American cities less than 600 miles apart could be replaced by high-speed electric ‘bullet’ trains travelling over 200 miles per hour, providing a quicker, safer, and cleaner way to get around. This would remove 80% of the flights within the USA, but would require high-speed trains running up and down the east and west coasts—with connections to the two major hubs of Chicago and Atlanta. This sort of high-speed train network already exists in Japan, South Korea, and parts of China and the EU, it just needs to be extended to the rest of the world.
The 2020/1 Covid-19 pandemic has boosted the use of internet and video-conferencing, showing a lot of commuting can be avoided as many people are happier working from home. It has also demonstrated that many international meetings, including huge scientific conferences, can be done very successfully using remote access technology. If this leads to a long-term decline in local and international travel then decarbonizing our transport networks will become easier.
Fossil-fuel subsidies
One of the major political problems with reducing carbon emissions concerns energy subsidies. First, there are huge fossil-fuel subsidies, which continue to make oil, gas, and coal relatively cheap. Second, there is resistance to providing subsidies and tax incentives to the energy companies to build and supply renewable energy at competitive rates. A recent report from the International Monetary Fund suggests that the fossil-fuel industry receives over $5.2 trillion per year in subsidies (nearly twice the size of the UK’s annual GDP)—this includes direct payments, tax breaks, reduced retail prices, and the cost of climate change damage. Of this governments provide at least $775 billion to $1 trillion as subsidies and at least $444 billion per year in direct funding to oil, gas, and coal companies to support exploration, extraction, and development. There is also a tremendous security cost associated with fossil fuels. A large part of foreign policy and military strategy for many countries involves protecting shipping lines for fossil fuels. The US military spends at least $81 billion a year protecting oil supplies. In comparison there are no aircraft carriers defending wind turbine supply chains or strategic silicon reserves for solar panels.
The IMF report shows that fossil fuels account for 85% of all global subsidies and that they remain a large part of domestic policies. Had nations reduced subsidies in such a way as to create efficient fossil-fuel pricing in 2015, the IMF believes that it ‘would have lowered global carbon emissions by 28% and fossil-fuel air pollution deaths by 46%, and increased government revenue by 3.8% of GDP.’ It seems fossil-fuel subsidies are bad for the environment and bad for the economy.
So why do fossil-fuel subsidies persist? This may be down to the ownership of the major oil and gas companies. Out of the top 26 oil and gas companies only seven are private companies; the other 19 are fully or partly owned by countries. Hence the state-owned companies are making huge amounts of money for the country and will continue to be given state aid in the form of subsidies and tax breaks to ensure that they are competitive with other oil and gas producing nations. This is only set to get worse with fracking and the shale gas revolution, with many countries such as the USA and the UK having found new reserves of natural gas underground.
Carbon trading, taxation, and offsetting
There are three main policy approaches that can be used to help reduce carbon net emissions. The first way to reduce carbon emissions is to impose a carbon tax on activities and goods that emit a large amount of carbon. Most economists agree that carbon taxes are the most efficient and effective way to curb emissions, with the least adverse effects on the economy. To avoid these taxes being regressive the income should be used to support the least well off in society who will be the worst affected by these taxes. Carbon taxes have been implemented in 25 countries, while 46 countries put some form of price on carbon, either through carbon taxes or emissions trading schemes.
The second approach, as discussed in Chapter 7, is carbon trading, whereby carbon emissions are limited by issuing of carbon permits. Carbon trading can drive innovation and drive down costs. It is also a way of making renewable energy and CCS economically viable. Some emissions trading schemes allow companies to buy carbon offsets either nationally or internationally to count against their total emissions.
A carbon offset is defined as a reduction in emissions of CO2 or other GHGs made in order to compensate for emissions made elsewhere. This can be either by increased carbon storage through reforestation programmes or by retiring or removing emissions, for example closing down a coal-fired power station. There are two main carbon offsetting systems: the UN CDM and the voluntary markets. The CDM has been described in Chapter 7 and involves UN-certified programmes in developing countries being funded to make significant GHG savings. The voluntary system peaked in volume in 2008 but has seen a substantial increase since 2018. This is because a large number of companies around the world have adopted science-based targets, which means they want to be carbon neutral by 2050 if not earlier. They include fifteen airlines, such as EasyJet, British Airways, and Emirates, which have all announced major carbon offset schemes.
Offsets are an important policy tool and can help reduce total emissions, especially in sectors where it is very difficult at the moment to reduce emissions. New national and international regulations are required to ensure proper monitoring and verification of offsets. Moreover, oversight is required to ensure that companies do not game the system by creating emissions just so that they can be paid to stop them. For example, one Chinese company generated $500 million in carbon offsets by installing a $5 million incinerator to burn the hydrofluorocarbons (HFCs) produced by the manufacture of refrigerants. Many companies followed this approach, and HFCs are no longer allowed under offset schemes.
Reforestation and rewilding
One of the most important ways to remove CO2 from the atmosphere is through reforestation and rewilding. Since the beginning of agriculture it has been estimated that humans have cut down 3 trillion trees—about half the trees on Earth. So we know that the Earth can sustain a much larger forested area. Rewilding habitats and reforesting may be easier in the future as the world is already becoming a wilder place. This may seem counterintuitive, given that the global population will grow from 7.8 billion today to 10 billion by 2050, but by then nearly 70% of us will live in cities and we will have abandoned many remote rural areas, making them ripe for restoration. Already, in Europe, 2.2 million hectares of forest has regrown per year between 2000 and 2015. In Spain, forest cover has increased from 8% of the country’s territory in 1900 to 25% today, while in the UK forest cover hit a low of 5% after the First World War and is now back up to 13%.
Massive reforestation isn’t a pipe dream; it can have real benefits for people. In the late 1990s, environmental deterioration in western China became critical, with vast areas resembling the Dust Bowl of the American Midwest in the 1930s. Six bold programmes were introduced, targeting over 100m hectares of land for reforestation. Grain for Green is the largest and best known of these. These radical tree-planting programmes had an amazing effect as the trees stabilized the soils, greatly reducing soil erosion and the impacts of flooding. Through transpiration, the trees added moisture to the atmosphere, reducing evaporation and water loss. Once the forests reached a critical size and area they also started to stabilize the rainfall. All these impacts combined to boost local agricultural production. The ongoing programme has also helped to alleviate poverty as direct payments were made to farmers to set aside their land for reforestation. This was an excellent example of the win-win solution required for climate change as it increased carbon storage, improved the local environment, and helped alleviate extreme poverty.
In 2019 researchers claimed in the journal Science that covering 900m hectares of land—roughly the size of the continental US—with 1 trillion trees could store up to 205 billion tonnes of carbon, about two-thirds of the carbon that humans have already put into the atmosphere. The ‘1 trillion trees’ mantra has caught the popular imagination and even President Trump declared at the Davos meeting that this was a good idea. The only problem is that the research that produced this high carbon number was fundamentally flawed and in fact the IPCC and other studies suggest that new forests could store on average an extra 57 billion tonnes of carbon by the end of the century. This is still a large number, but considering we put 11 billion tonnes of carbon into the atmosphere per year, this represents only five years of human pollution. So reforestation is not an alternative to rapid and deep cuts in our fossil-fuel emissions. But later in this century we will require negative carbon emissions to keep the global warming to 1.5˚C—one of the key ways of creating negative emissions is through reforestation.
Already 63 countries have joined the Bonn Challenge and pledged to restore 350m hectares of degraded land to forest worldwide. That’s an area fifteen times the size of the UK. But there is another issue. Massive reforestation only works if the world’s current forest cover is maintained and increased. As noted earlier, deforestation of the Amazon rainforest—the world’s largest—has increased since Brazil’s far-right president, Jair Bolsonaro, has been in power. Current estimates suggest areas of rainforest the size of a football pitch are being cleared every single minute.
Reforestation and afforestation are fundamentally limited by the land area available, as trees can only hold a finite amount of carbon. We must also remember that reforestation is not always the best option, and this is why the term ‘rewilding’ is used in conjunction with reforestation. For example, draining wetlands or peatlands to plant forests is counter-productive, as the carbon storage will be lower and losses of biodiversity will be considerable. So in each region of the world the most appropriate restoration project must be applied. This could be re-wetting wetlands, preserving peatlands, re-growing mangrove forests, or maintaining open grasslands. If an area is suitable for reforestation, decisions have to be made about the most appropriate species for that area in terms of current and future climate and how to increase local biodiversity and other ecological services. One of the criticisms of the Bonn Challenge is that about half the pledges involve large-scale commercial forest plantations. Plantations only lock up carbon while the trees are growing, and much of this is returned when they are harvested. In any case, monoculture is bad for biodiversity.
Geoengineering or technofixes
Geoengineering is the general term used for technologies that could be used to either remove GHGs from the atmosphere or to change the climate of the Earth (see Figure 40). Ideas considered under geoengineering range from the very sensible to the completely mad. Geoengineering is not an alternative to massive reductions in global GHG emissions. Instead, most people see geoengineering solutions as a fall back if we are unable or unwilling to cut GHG emissions quick enough.
40. The range of geoengineering approaches.
Carbon dioxide removal. There are three main approaches to the removal and storage of atmospheric CO2: biological, physical, and chemical.
Solar radiation management. Reducing the amount of sunlight hitting or being absorbed by the Earth will reduce the total energy budget and may result in a cooler Earth. As will be evident from the above, some geoengineering solutions are still just ideas and need a lot more work to see if they are even feasible. This is particularly true of the solar radiation management ideas, many of which sound like something out of a bad Hollywood B-movie. These suggestions include changing the albedo (see Chapter 4) of the Earth, to increase the amount of solar energy reflected back into space to balance the heating from global warming (Figure 40). Ideas to increase albedo include erecting massive mirrors in space, injecting aerosols into the atmosphere, making crops more reflective, painting all roofs white, increasing white cloud cover, and covering large areas of the world’s deserts with reflective polyethylene-aluminium sheets.
The fundamental problem with all of these approaches is that we have no way of predicting their overall effect on climate. Let us examine the mirrors in space idea put forward by Roger Angel, director of the Centre for Astronomical Adaptive Optics at the University of Arizona. First it would be expensive, requiring 16 trillion gossamer-light spacecraft costing at least $1 trillion and taking 30 years to launch. Second, like all the geoengineering ideas to change the Earth’s albedo, it may not work the way we hope it will work. These approaches are aimed at getting the Earth’s average temperature down, but they may change the distribution of temperature with latitude, which is what drives climate. Some climate models have shown that these approaches may give a different global climate, with the tropics being 1.5°C colder, the high latitudes 1.5°C warmer, and precipitation varying unpredictably around the world.
Geoengineering governance
One of the major issues with geoengineering is how to govern different groups, companies, and countries playing with the global climate system. There are a great many ethical issues that arise when considering how changing regional and global climate may affect countries differently. There may be overall positive results but minor changes in rainfall patterns, which could mean that whole countries receive too little or too much rain, possibly resulting in disaster. There are three main views on geoengineering: (1) it is a route to buying back some time to allow the UNFCCC negotiations to catch up so that we can achieve net zero carbon by 2050; (2) it represents a dangerous manipulation of the Earth system and may be intrinsically unethical; or (3) it is strictly an insurance policy to support mitigation and adaptation efforts if they fail to be sufficient on their own. Even if research is allowed to go ahead and geoengineering solutions are required, like many emerging areas of modern technology, new flexible governance and regulatory frameworks will be required. Currently there are many international treaties with a bearing on geoengineering, and it seems that no single instrument applies. Hence geoengineering, like climate change, challenges our nation-state view of the world, and new ways of governing will be required in the future.
If we are to solve the problems of climate change, we need to tackle two fundamental issues. The first is how we can reduce to net zero the amount of GHG pollution that we are emitting, while enabling the very poorest countries to develop. The world’s population is currently just over 7.8 billion and it is likely to rise and plateau at 10 billion by 2050. That adds up to 8 billion people aspiring to have the same lifestyle as those living in the developed world, with a potentially huge increase in GHG emissions in this century, if they follow the same development pathway to fuel this consumer dream. The second issue is whether as a society we are prepared to invest the relatively small amount, about 1–3% of the world’s GDP, to offset a much larger bill in the future. If so, then we have the technology at the moment both to protect our population from climate change and to mitigate the huge predicted emissions of GHGs over the next 80 years. Energy efficiency, renewable energy, CCS, carbon trading, and offsetting all have a role to play. We must also consider ‘disruptive technologies’, that is, new technologies that we may not yet have even thought of that could change the way we produce or use energy. For example, most of us cannot think of life without a mobile phone or a computer, but this technology has been around for only a few decades, showing how quickly we can become accustomed to change. There are also huge amounts of money to be made from opportunities surrounding changes to our energy use and our personal lifestyles, and, as we will see in Chapter 9, there may be many win-win situations whereby quality of life can be improved at the same time as stabilizing the climate of our planet.