What are the solutions to Climate Change?
The solution to climate change is obvious: we must reduce our emissions of greenhouse gasses back down to preindustrial levels. Nobody is arguing about that, rather it is how we go about doing this that generates a lot of controversy.
In their recent sixth assessment report the Inter Governmental Panel on Climate Change (IPCC) examine different ways in which humanity could reduce its emissions of greenhouse gasses over the coming century in order to prevent climate change. Each of these scenarios is referred to as an emissions trajectory. For each emission trajectory, the IPCC then model what effect following that pathway is going to have on the global climate by 2100, in order to determine what emissions trajectory we ought to follow. The results of that modelling are shown in the graph below.
The IPCC are clear that global warming must be limited to 1.5C in order to avoid the dangers of hitting tipping points and triggering a runaway global warming scenario which would devastate life on earth. In the five emissions pathways modelled above, only one of them keeps global temperatures below 1.5C by 2100 (the light blue line).
For this reason, any potential solution to climate change must follow this emissions trajectory. This trajectory requires strong reductions of emissions of 25-45% by 2030, and then a more gradual reduction to net zero by 2050, after which there must be no more emissions of greenhouse gasses.
The year 2030 is only 7 years away, and this has led many to declare that we only have a few years in which to save the planet from runaway climate change. Yet at present, global emissions of greenhouse gasses are still on the rise, and show no sign of slowing. Meeting these targets and restricting global warming to 'safe' levels requires immediate action on a scale never before seen in history, and radical changes to the way we live.
So how can we go about doing this? The obvious way would be for us all to give up carbon intensive lifestyles and live a more simple life. That, however, is considered wildly unrealistic, as the world population is heavily committed to carbon intensive lifestyles and has shown time and again that it is very unwilling to give those up, even if it risks global climatic meltdown and a devastated future for their descendants.
Perhaps the most credible solution has been that offered by the International Energy Agency (IEA), the global body responsible for monitoring trends in the energy sector for the major industrialised countries of the world. In 2021, in preparation for the global climate summit that was held in Glasgow, the UK government commissioned the IEA to provide all member countries with a roadmap to achieve net zero emissions by 2050. The result was a landmark report called Net Zero by 2050: A Roadmap for the Global Energy Sector [2].
The report considered that there was still a narrow pathway to achieve net zero emissions by 2050, but that it required urgent action on a global scale. Some of the main actions required were as follows:
All governments must cease to grant any new oil, coal, or gas extraction activities from 2021.
Generate electricity without emissions. Using sources such as wind, solar and water power alongside advances in energy storage. To reach these targets, the IEA say 50% of all electricity must be generated by low emissions sources, such as renewables, by 2025. In the heavily industrialised economies, all electricity generation is to be net zero by 2035, and by 2050, 90% of all electricity generation should be from low emissions sources.
Use vehicles and equipment that are powered by electricity instead of fossil fuels. If the electricity we are producing is clean then many of the biggest sources of greenhouse gasses can be avoided by switching to electricity. For example, according to the IEA 60% of all car sales need to be electric vehicles by 2030, and all sales of petrol or diesel driven vehicles should be phased out by 2035.
Use energy more efficiently. More efficient technologies and processes that reduce energy use can also reduce emissions significantly. For example, if the amount of energy we use were to remain the same but our cars, devices, power stations, homes, industries, and so on, were to become 20% more efficient, then fossil fuel use would drop by 20%, as would emissions of greenhouse gasses. Increasing energy efficiency is a critical part of reducing emissions.
Remove carbon dioxide from the atmosphere. This can be done with technologies that directly capture CO2 from the air and trap it as a solid so that it cannot enter the atmosphere, such as Carbon Capture and Mineralisation (CCM). It can even be turned into a useful product that can be sold commercially. In the IEA's roadmap by 2035 this the amount of CO2 directly captured from the air will amount to 3 gigatonnes of CO2, about 10% of current (2023) global emissions of CO2.
Change our habits and behaviours. We must adopt more low carbon habits and behaviours, such as cycling and walking more, eating less meat, flying less, and so on. In the IEA roadmap these individual behaviour changes lead to a global drop in emissions of around 8% by 2050.
We only have a short window of opportunity to realise the IEA roadmap to net zero by 2050, but governments around the world, including the UK, are continuing to invest heavily in fossil fuels and to develop more sources of fossil fuels. These new fossil fuel projects will have lifetimes of several decades, and will continue to pour greenhouse gasses into the atmosphere beyond 2050, using up the limited carbon budget that we have. This means that the window of opportunity for achieving this roadmap is, according to the IEA, becoming narrower and narrower. Perhaps the biggest action required that is not on the IEA roadmap is a global uprising by the citizens of the world to demand an immediate shift away from fossil fuels, and no more licensing of fossil fuel extraction. It is almost certain that it is only within a context like that that governments are going to act with the urgency required.
