Our key takeaway: Limiting global warming to 1.5°C is possible. But there are only three years left for us to take the actions needed to enable the deep emissions reductions needed across all sectors.
The IPCC sets out the way in which the systems need to transform to enable us to stay on the safer path: all sectors will need to transform, although some more than others. We will also have to change our own ways – and let us not forget the important role regulation, policy and investment plays to incentivise and support the transformation ahead. As the IPCC Working Group III Co-Chair Jim Skea remarks: “Climate change is the result of more than a century of unsustainable energy and land use, lifestyles and patterns of consumption and production. … This report shows how taking action now can move us towards a fairer, more sustainable world.”
The UN’s Intergovernmental Panel on Climate Change (IPCC) has released the third part of its sixth assessment report (AR6). After discussing the physical science of climate change in its first part (that we discuss here) and impacts of climate change (discussed here), this third instalment focuses on mitigation, i.e., the reduction of greenhouse gas (GHG) emissions and removal of carbon dioxide (CO2) from the atmosphere. The IPCC has put together a helpful press conference presentation that you can look at here. Here are just a few highlights from the report, and you can also find WRI’s helpful summary here:
- Immediate action necessary: Limiting global warming to 1.5°C is possible, but only if we act immediately with deep emissions reductions across all sectors. Global GHG emissions need to peak before 2025, and then reduce by 43% by 2030 if we are to limit warming to 1.5°C. This means that we only have the next three years to preserve our chances of meeting the Paris Agreement’s 1.5°C. We also need to limit climate overshoot (exceeding 1.5°C temporarily, before then reducing the temperature) in light of the potential for irreversible climate impacts.
- Move over fossil fuel, enter carbon removal: With a pathway of limiting warming to 1.5°C, we can only emit another net 510 Gt of CO2. However, we will already emit 850 Gt of CO2 if we proceed with existing and planned fossil fuel infrastructure. In other words, if we continue with existing fossil fuels plans, we will already have failed in limiting global warming to 1.5°C. Recommended strategies include retiring existing fossil fuel infrastructure, cancelling new projects, retrofitting fossil-fueled power plants with carbon capture and storage (CCS) technologies, and switching to lower-carbon fuels. To reach the Paris Agreement goal, carbon removal will be key. Carbon removal approaches exist on land (e.g. sequestering and storing carbon in trees and soil) and in the ocean (e.g. cultivating seaweed), as well as through technological approaches (e.g. direct air capture). (WRI has a nice graph of the options here). Enhanced attention needs to be placed on carbon removal technologies, while considering how these technologies may themselves result in impacts (e.g. BECCS – bioenergy with carbon capture and storage – relies on biomass crop production which can result in deforestation and threaten food security)
- Systems transformations: The IPCC highlights the rapid transformations that need to take place across all systems. The report delves into energy, land use, industry, urban, buildings, transport as well as demand and services. For instance, when it comes to energy, grids need to be predominantly powered by renewables and storage, complemented by a mix of nuclear, a small amount of fossil fuels with Carbon Capture and Storage (CCS), and/or other forms of clean power. In sectors where electrification will be a challenge, there will be a role for alternative fuels, such as hydrogen and sustainable biofuels. As another example, when it comes to land use and food systems, the IPCC places an emphasis on protecting and restoring natural ecosystems to remove carbon, such as forests, peatlands, coastal wetlands, savannas and grasslands. This – coupled with curbing food waste, shifting to more sustainable diets and reducing the carbon footprint of food production – can play an important role in curbing emissions. The IPCC also delves into our own role as consumers, which can include using energy more efficiently, shifting to plant-based diets and reducing food waste, as well as walking, cycling and avoiding long-haul flights. In the words of IPCC Working Group III Co-Chair Priyadarshi Shukla: “Having the right policies, infrastructure and technology in place to enable changes to our lifestyles and behaviour can result in a 40-70% reduction in greenhouse gas emissions by 2050. This offers significant untapped potential.”