The United Nations International Panel on Climate Change (IPCC) has just published its most comprehensive report so far. It finds that ‘human activities, principally through emissions of greenhouse gases, have unequivocally caused global warming’. This has led to widespread and rapid changes in climate and biodiversity and to more extreme weather patterns, such as droughts, floods and hurricanes. What is more, the distribution of these effects is uneven, with communities who have contributed the least to current climate change being disproportionately affected.
At the 2015 COP21 climate change conference in Paris (see also), it was agreed to adopt policies to limit the increase in global temperatures to ‘well below’ 2°C above pre-industrial levels and to make an effort to limit it to 1.5°C. Global temperatures have already risen 1.1°C above 1850–1900 levels and are set to reach 1.5°C in the early 2030s. Every increment of global warming will intensify ‘multiple and concurrent hazards’.
Deep, rapid and sustained reductions in emissions would slow down the rise in global temperatures, but even with such reductions, temperatures will still exceed 1.5°C in the next few years and, even under the best-case scenario, would not fall below 1.5°C again until the end of the 21st century. Under more pessimistic scenarios, global temperatures could rise to 2.7°C above pre-industrial levels by the end of the century under an intermediate greenhouse gas emissions scenario and to 4.4°C under a very high emissions scenario. Anything above 2°C would be likely to have catastrophic effects. The longer countries wait to take action, the greater the rise in global temperatures and hence the greater the damage and the more costly it will be to rectify it.
‘For any given future warming level… projected long-term impacts are up to multiple times higher than currently observed (high confidence). Risks and projected adverse impacts and related losses and damages from climate change escalate with every increment of global warming (very high confidence). Climatic and non-climatic risks will increasingly interact, creating compound and cascading risks that are more complex and difficult to manage (high confidence).’ (Paragraph B2)
But the report is not all ‘doom and gloom’. It is possible to limit global warming to 1.5°C or only a little over by making rapid, deep and, in most cases, immediate greenhouse gas emissions reductions in all sectors and reaching net zero emissions in the early 2050s. Science and technology have the answers – answers that are now much cheaper and more available than back in 2015 when the 1.5°C target was agreed. But what it does require is doing ‘everything, everywhere, all at once’. And that requires political will and the right economic incentives.
The politics and economics of achieving net zero
In terms of the politics, there is general global agreement by governments about the likely effects of climate change. And most governments agree that action needs to be taken. However, there are three key political problems.
The first is that the costs of action will be borne now, while the benefits of action will accrue over a much longer period of time. This links to the second problem – the mismatch between the lives of governments and the long-term effects of climate change. If governments put off doing anything now and merely promise that something will be done in the future, they will not have to take unpopular actions, such as raising taxes on energy, private transport and certain goods or banning various activities. Future governments will have to sort things out, by when, although the problems will be greater, the existing politicians will no longer be in power.
The third problem concerns the distribution of the costs and benefits of action. The major emitters of carbon are the rich countries, while the major sufferers are poor people in countries subject to drought, flooding and rising sea levels. Not surprisingly, who should cut down on emissions and pay for the mitigation necessary in many of the poorer countries is a difficult political issue, which is why it’s much easier to say what needs to be achieved overall than precisely what measures should be taken by which countries.
These problems reflect the fact that many, if not most, of the environmental costs of production and consumption are external costs – costs borne, not by the direct producer or consumer, but by other people at other places and/or in the future.
Nevertheless, the relative costs of moving to greener production and consumption are falling. The costs of renewable energy, including solar power, onshore and offshore wind and hydroelectric power are falling relative to that generated from fossil fuels. At the same time, the take up of electric cars is likely to continue rising as battery technology improves. This does, of course, require an increase in charging infrastructure. Domestic heat pump technology is improving and home insulation methods are becoming more efficient.
Persuading consumers and firms to take account of environmental externalities could in part be achieved by education. It makes it much easier for politicians to take appropriate action now if their populations are on board. There has been increasing awareness over the years of the environmental impact of people’s actions. People have become more willing to take responsibility for the world that future generations will inherit. This is helped both by education in schools and colleges and by frequent items in the media.
But incentives also have a major part to play. To internalise environmental externalities, external costs could be taxed and external benefits subsidised.
The effect of a carbon tax on production
The use of taxes to reduce activities with negative environmental externalities is illustrated in the diagram (click here for a PowerPoint). It takes the case of carbon emissions from coal-fired electricity generation in a large country. To keep the analysis simple, it is assumed that all electricity in the country is generated from coal-fired power stations and that there are many such power stations, making the market perfectly competitive.
It is assumed that all the benefits from electricity production accrue solely to the consumers of electricity (i.e. there are no external benefits from consumption). Marginal private and marginal social benefits of the production of electricity are thus the same (MPB = MSB). The curve slopes downwards because, with a downward-sloping demand for electricity, higher output results in a lower marginal benefit (diminishing marginal utility).
Competitive market forces, with producers and consumers responding only to private costs and benefits, will result in a market equilibrium at point a in the diagram: i.e. where demand equals supply. The market equilibrium price is P0 while the market equilibrium quantity is Q0. However the presence of external costs in production means that MSC > MPC. In other words, MEC = b – a.
The socially optimal output would be Q* where P = MSB = MSC, achieved at the socially optimal price of P*. This is illustrated at point d and clearly shows how external costs of production in a perfectly competitive market result in overproduction: i.e. Q0 > Q*. From society’s point of view, too much electricity is being produced and consumed.
If a carbon tax of d – c is imposed on the electricity producers, it will now be in producers’ interests to produce at Q*, where their new private marginal costs (including tax) equals their marginal private benefit.
But this brings us back to the politics of measures to reduce emissions. People do not like paying higher taxes. In his latest Budget, the UK Chancellor, Jeremy Hunt, decided not to raise fuel duties by the 12p that had been previously planned, despite fuel prices having recently fallen. Meanwhile, charging prices for electric cars have risen.
Other economic measures
A simpler method for dealing with environmental externalities is ban certain activities that omit CO2. For example, in the UK there will be a ban on the sale of new petrol and diesel cars and vans from 2030 (with the exception of some low-emission hybrids until 2035). In the EU there will be a similar ban from 2035. Clearly, such measures are only suitable when there are non-emitting alternatives.
Another alternative is a cap-and-trade system, such as the European Emissions Trading Scheme. It involves setting quotas for emissions and allowing firms which manage to cut emissions to sell their surplus permits to less efficient firms. This puts a price pressure on firms to be more efficient. But the quotas (the ‘cap’) must be sufficiently tight if emissions are going to be cut to desired levels. Nevertheless, it is an efficient way of cutting emissions as it gives a competitive advantage to low-emission producers.
If the problem of global warming is to be limited to 1.5°C, or only very little above, multiple solutions will need to be found and there must be a combination of political will, economic incentives and the mobilisation of scientific and technical know-how. As the Secretary-General of the United Nations, António Guterres, stated in launching the new report:
This report is a clarion call to massively fast-track climate efforts by every country and every sector and on every timeframe. In short, our world needs climate action on all fronts – everything, everywhere, all at once.
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- Expert reaction to the AR6 synthesis report, as published by the IPCC
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- Why might countries not do ‘everything, everywhere, all at once’ to avert climate change?
- What might an optimist conclude from the ICC report?
- To what extent is climate change an economic problem?
- On a diagram similar to the one above, show how a subsidy could be used to internalise positive externalities.
- How might countries reduce the consumption of fossil fuels in the most efficient way? Are they likely to want to do this? Explain.
- Is a ‘cap-and-trade’ (tradable permits) system (a) an effective means of reducing emissions; (b) an efficient system?
The UN’s Intergovernmental Panel on Climate Change (IPCC) has just published the first part of its latest seven-yearly Assessment Report (AR6) on global warming and its consequences (see video summary). The report was prepared by 234 scientists from 66 countries and endorsed by 195 governments. Its forecasts are stark. World temperatures, already 1.1C above pre-industrial levels, will continue to rise. This will bring further rises in sea levels and more extreme weather conditions with more droughts, floods, wildfires, hurricanes and glacial melting.
The IPCC looked at a number of scenarios with different levels of greenhouse gas emissions. Even in the most optimistic scenarios, where significant steps are taken to cut emissions, global warming is set to reach 1.5C by 2040. If few or no cuts are made, global warming is predicted to reach 4.4C by 2080, the effects of which would be catastrophic.
The articles below go into considerable detail on the different scenarios and their consequences. Here we focus on the economic causes of the crisis and the policies that need to be pursued.
Global success in reducing emissions, although partly dependent on technological developments and their impact on costs, will depend largely on the will of individuals, firms and governments to take action. These actions will be influenced by incentives, economic, social and political.
Economic causes of the climate emergency
The allocation of resources across the world is through a mixture of the market and government intervention, with the mix varying from country to country. But both market and government allocation suffer from a failure to meet social and environmental objectives – and such objectives change over time with the preferences of citizens and with the development of scientific knowledge.
The market fails to achieve a socially efficient use of the environment because large parts of the environment are a common resource (such as the air and the oceans), because production or consumption often generates environmental externalities, because of ignorance of the environmental effects of our actions, and because of a lack of concern for future generations.
Governments fail because of the dominance of short-term objectives, such as winning the next election or appeasing a population which itself has short-term objectives related to the volume of current consumption. Governments are often reluctant to ask people to make sacrifices today for the future – a future when there will be a different government. What is more, government action on the environment which involves sacrifices from their own population, often primarily benefit people in other countries and/or future generations. This makes it harder for governments to get popular backing for such policies.
Economic systems are sub-optimal when there are perverse incentives, such as advertising persuading people to consume more despite its effects on the environment, or subsidies for industries producing negative environmental externalities. But if people can see the effects of global warming affecting their lives today, though fires, floods, droughts, hurricanes, rising sea levels, etc., they are more likely to be willing to take action today or for their governments to do so, even if it involves various sacrifices. Scientists, teachers, journalists and politicians can help to drive changes in public opinion through education and appealing to people’s concern for others and for future generations, including their own descendants.
Policy implications of the IPCC report
At the COP26 meeting in Glasgow in November, countries will gather to make commitments to tackle climate change. The IPCC report is clear: although we are on course for a 1.5C rise in global temperatures by 2040, it is not too late to take action to prevent rises going much higher: to avoid the attendant damage to the planet and changes to weather systems, and the accompanying costs to lives and livelihoods. Carbon neutrality must be reached as soon as possible and this requires strong action now. It is not enough for government to set dates for achieving carbon neutrality, they must adopt policies that immediately begin reducing emissions.
The articles look at various policies that governments can adopt. They also look at actions that can be taken by people and businesses, actions that can be stimulated by government incentives and by social pressures. Examples include:
- A rapid phasing out of fossil fuel power stations. This may require legislation and/or the use of taxes on fossil fuel generation and subsidies for green energy.
- A rapid move to green transport, with investment in charging infrastructure for electric cars, subsidies for electric cars, a ban on new petrol and diesel vehicles in the near future, investment in hydrogen fuel cell technology for lorries and hydrogen production and infrastructure, cycle lanes and various incentives to cycle.
- A rapid shift away from gas for cooking and heating homes and workplaces and a move to ground source heating, solar panels and efficient electric heating combined with battery storage using electricity during the night. These again may require a mix of investment, legislation, taxes and subsidies.
- Improvements in energy efficiency, with better insulation of homes and workplaces.
- Education, public information and discussion in the media and with friends on ways in which people can reduce their carbon emissions. Things we can do include walking and cycling more, getting an electric car and reducing flying, eating less meat and dairy, reducing food waste, stopping using peat as compost, reducing heating in the home and putting on more clothes, installing better insulation and draught proofing, buying more second-hand products, repairing products where possible rather than replacing them, and so on.
- Governments requiring businesses to conduct and publish green audits and providing a range of incentives and regulations for businesses to reduce carbon emissions.
It is easy for governments to produce plans and to make long-term commitments that will fall on future governments to deliver. What is important is that radical measures are taken now. The problem is that governments are likely to face resistance from their supporters and from members of the public and various business who resist facing higher costs now. It is thus important that the pressures on governments to make radical and speedy reductions in emissions are greater than the pressures to do little or nothing and that governments are held to account for their actions and that their actions match their rhetoric.
- Some climate changes now irreversible, says stark UN report
Channel 4 News, Alex Thomson (9/8/21)
- Climate change: IPCC report is ‘code red for humanity’
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- Climate change: Five things we have learned from the IPCC report
BBC News, Matt McGrath (10/8/21)
- Climate Scientists Reach ‘Unequivocal’ Consensus on Human-Made Warming in Landmark Report
Bloomberg Green, Eric Roston and Akshat Rathi (9/8/21)
- Climate change: Seven key takeaways from the IPCC climate change report
Sky News, Philip Whiteside (10/8/21)
- IPCC report: global emissions must peak by 2025 to keep warming at 1.5°C – we need deeds not words
The Conversation, Keith Baker (9/8/21)
- This is the most sobering report card yet on climate change and Earth’s future. Here’s what you need to know
The Conversation, Pep Canadell, Joelle Gergis, Malte Meinshausen, Mark Hemer and Michael Grose (9/8/21)
- IPCC report: how to make global emissions peak and fall – and what’s stopping us
The Conversation, Matthew Paterson (9/8/21)
- World’s 1.5C goal slipping beyond reach without urgent action, warns landmark IPCC climate report
Independent, Daisy Dunne and Louise Boyle (9/8/21)
- IPCC report: 14 ways to fight the climate crisis after publication of ‘Code Red’ warning
Independent, Harry Cockburn (10/8/21)
- Major climate changes inevitable and irreversible – IPCC’s starkest warning yet
The Guardian, Fiona Harvey (9/8/21)
- Climate scientists have done their bit. Now the pressure is on leaders for COP26.
CNN, Ivana Kottasová and Angela Dewan (10/8/21)
- 21 For 21: The Climate Change Actions Scotland Needs Now
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- How to build support for ambitious climate action in 4 steps
The Conversation, Sarah Sharma and Matthew Hoffmann (4/3/21)
- Scientists have finally added world politics to their climate models
Quartz, Michael J Coren (9/8/21)
- Summarise the effects of different levels of global warming as predicted by the IPCC report.
- To what extent is global warming an example of the ‘tragedy of the commons’?
- How could prices be affected by government policy so as to provide an incentive to reduce carbon emissions?
- What incentives could be put in place to encourage people to cut their own individual carbon footprint?
- To what extent is game theory relevant to understanding the difficulties of achieving international action on reducing carbon emissions?
- Identify four different measures that a government could adopt to reduce carbon emissions and assess the likely effectiveness of these measures.
In December 2015, countries from around the world met in Paris at the United Nations Intergovernmental Panel on Climate Change (IPCC). The key element of the resulting Paris Agreement was to keep ‘global temperature rise this century well below 2 degrees Celsius above pre-industrial levels and to pursue efforts to limit the temperature increase even further to 1.5 degrees Celsius.’ At the same time it was agreed that the IPCC would conduct an analysis of what would need to be done to limit global warming to 1.5°C. The IPPC has just published its report.
The report, based on more than 6000 scientific studies, has been compiled by more than 80 of the world’s top climate scientists. It states that, with no additional action to mitigate climate change beyond that committed in the Paris Agreement, global temperatures are likely to rise to the 1.5°C point somewhere between 2030 and 2040 and then continue rising above that, reaching 3°C by the end of the century.
According to the report, the effects we are already seeing will accelerate. Sea levels will rise as land ice caps and glaciers melt, threatening low lying coastal areas; droughts and floods will become more severe; hurricanes and cyclones will become stronger; the habits of many animals will become degraded and species will become extinct; more coral reefs will die and fish species disappear; more land will become uninhabitable; more displacement and migration will take place, leading to political tensions and worse.
The problem of greenhouse gas emissions and global warming is a classic case of the tragedy of the commons. This is where people overuse common resources, such as open grazing land, fishing grounds, or, in this case, the atmosphere as a dump for emissions. They do so because there is little, if any, direct short-term cost to themselves. Instead, the bulk of the cost is borne by others – especially in the future.
There is another related tragedy, which has been dubbed the ‘tragedy of incumbents’. This is a political problem where people in power want to retain that power and do so by appealing to short-term selfish interests. The Trump administration lauds the use of energy as helping to drive the US economy and make people better off. To paraphrase Donald Trump ‘Climate change may be happening, but, hey, let’s not beat ourselves up about it and wear hair shirts. What we do will have little or no effect compared with what’s happening in China and India. The USA is much better off with a strong automobile, oil and power sector.’
What’s to be done?
According to the IPCC report, if warming is not to exceed 1.5℃, greenhouse gas emissions must be reduced by 45% by 2030 and by 100% by around 2050. But is this achievable?
The commitments made in the Paris Agreement will not be nearly enough to achieve these reductions. There needs to be a massive movement away from fossil fuels, with between 70% and 85% of global electricity production being from renewables by 2050. There needs to be huge investment in green technology for power generation, transport and industrial production.
In addition, the report recommends investing in atmospheric carbon extraction technologies. Other policies to reduce carbon include massive reforestation.
Both these types of policies involve governments taking action, whether through increased carbon taxes on either producers or consumer or both, or through increased subsidies for renewables and other alternatives, or through the use of cap and trade with emissions allocations (either given by government or sold at auction) and carbon trading, or through the use of regulation to prohibit or limit behaviour that leads to emissions. The issue, of course, is whether governments have the will to do anything. Some governments do, but with the election of populist leaders, such as President Trump in the USA, and probably Jair Bolsonaro in Brazil, and with sceptical governments in other countries, such as Australia, this puts even more onus on other governments.
Another avenue is a change in people’s attitudes, which may be influenced by education, governments, pressure groups, news media, etc. For example, if people could be persuaded to eat less meat, drive less (for example, by taking public transport, walking, cycling, car sharing or living nearer to their work), go on fewer holidays, heat their houses less, move to smaller homes, install better insulation, etc., these would all reduce greenhouse gas emissions.
Finally, there is the hope that the market may provide part of the solution. The cost of generating electricity from renewables is coming down and is becoming increasingly competitive with electricity generated from fossil fuels. Electric cars are coming down in price as battery technology develops; also, battery capacity is increasing and recharging is becoming quicker, helping encourage the switch from petrol and diesel cars to electric and hybrid cars. At the same time, various industrial processes are becoming more fuel efficient. But these developments, although helpful, will not be enough to achieve the 1.5°C target on their own.
Videos and audio
- We must reduce greenhouse gas emissions to net zero or face more floods
The Guardian, Nicholas Stern (8/10/18)
- Rapid, unprecedented change needed to halt global warming – U.N.
Reuters, Nina Chestney and Jane Chung (8/10/18)
- Final call to save the world from ‘climate catastrophe’
BBC News, Matt McGrath (8/10/18)
- New UN report outlines ‘urgent, transformational’ change needed to hold global warming to 1.5°C
The Conversation, Mark Howden and Rebecca Colvin (8/10/18)
- Earth’s temperature to rise 1.5C as early as 2030 amid dire warnings from UN climate panel
The Telegraph (8/10/18)
- UN Climate Change Report: Everything You Need To Know
Huffington Post, Isabel Togoh (8/10/18)
- Thirty years of the IPCC
Physics World (8/10/18)
- 13 things you should know about 1.5
Unearthed, Zach Boren (8/10/18)
- Climate change impacts worse than expected, global report warns
National Geographic, Stephen Leahy (7/10/18)
- World to miss Paris climate targets by wide margin, says UN panel
Financial Times, Leslie Hook (8/10/18)
- We have 12 years to limit climate change catastrophe, warns UN
The Guardian, Jonathan Watts (8/10/18)
- Limiting warming to 1.5C is possible – if there is political will
The Guardian, Christiana Figueres (8/10/18)
- The Trump administration has entered Stage 5 climate denial
The Guardian, Dana Nuccitelli (8/10/18)
- ‘Unprecedented changes’ needed to stop global warming as UN report reveals islands starting to vanish and coral reefs dying
Independent, Josh Gabbatiss (8/10/18)
- Explain the extent to which the problem of global warming is an example of the tragedy of the commons. What other examples are there of the tragedy?
- Explain the meaning of the tragedy of the incumbents and its impact on climate change? Does the length of the electoral cycle exacerbate the problem?
- With the costs of low or zero carbon technology for energy and transport coming down, is there as case for doing nothing in response to the problem of global warming?
- Examine the case for and against using taxes and subsidies to tackle global warming.
- Examine the case for and against using regulation to tackle global warming.
- Examine the case for and against using cap-and-trade systems to tackle global warming.
- Is there a prisoners’ dilemma problem in getting governments to adopt policies to tackle climate change?
- What would be the motivation for individuals to ‘do their bit’ to tackle climate change? Other than altering prices or using regulation, how might the government or other agencies set about persuading people to ‘be more green’?
- If you were doing a cost–benefit analysis of some project that will have beneficial environmental impacts in the future, how would you set about adjusting the values of these benefits for the fact that they occur in the future and not now?