Expert Comment: Five new(s) and five olds in the sixth IPCC report on mitigating climate change
Tuesday 26th Apr 2022, 2.42pm
The headline insights from the final instalment of the IPCC’s sixth assessment report were clear:
- Evidence on what works to mitigate climate change is clearer than ever before.
- A low-carbon future means tackling demand for resources – not just their supply.
- It means innovation policies, not just carbon prices.
- And it involves people, not just technologies.
More than 600 scientists from over 65 countries synthesised the evidence on climate change mitigation and created the almost 3,000-page report. So how has the evidence shifted since the 2018 IPCC report on the related topic of limiting warming to 1.5°C?
By design, the IPCC is a cautious and slow-moving science-policy juggernaut, so nothing is truly new by the time the assessments are published. But there were certainly new emphases and new topics in this report. It is also revealing to see what survived the political negotiations on the ‘Summary for Policymakers’ text.
The IPCC is a cautious and slow-moving science-policy juggernaut, so nothing is truly new by the time the assessments are published. But there were certainly new emphases and new topics in this report
Five new emphases in the scientific evidence on climate change mitigation are:
- on managing energy demand,
- on high emitting individuals and status consumption,
- on innovation success stories,
- on climate policy effectiveness, and
- on carbon dioxide removal.
It is worth recapping the five olds – what we already knew.
First, the 1.5°C target of the Paris Agreement is very, very close to being out of reach. An increasing number of long-term mitigation pathways can no longer find feasible ways to reduce emissions fast enough. Existing and planned fossil fuel infrastructure alone commits the world to at least 2°C.
Second, a dramatic reversal is, therefore, needed in the upward trend of global greenhouse gas emissions. To limit warming to 1.5°C, emissions need to fall by 43% over this decade. Last decade they rose by 12%.
Third, major transitions are needed in energy, transport, buildings, and industry. This means net-zero carbon electricity and liquid fuels, and more efficient industrial processes.
Major transitions are needed in energy, transport, buildings, and industry. This means net-zero carbon electricity and liquid fuels, and more efficient industrial processes…These transitions are electrifying
It means electric vehicles, walking, cycling, shared and public travel, better urban planning. It means more ambitiously efficient building retrofits and new construction. These transitions are electrifying. Electricity is versatile, clean at the point-of-use, can be generated by many different low-carbon energy resources, and hugely improves efficiency.
Fourth, policies and actions to mitigate climate change are getting cheaper. Many are now cost-effective and others have substantial co-benefits for health, air quality, and liveable cities. Mitigation options costing less than US$100/tCO2 could reduce global emissions by at least half by 2030. Fuel taxes for UK motorists imply a carbon price three times this level.
Fifth, mitigating climate change will affect who and where benefits from economic opportunities or bears economic risks. In particular, international trade in fossil fuels and energy-intensive goods will decline as the future becomes more renewable and more efficient. The geopolitics of energy that have characterised global development over the past hundred years will change.
These five insights may not surprise anyone working on climate change mitigation. But having them restated by the IPCC sixth assessment makes clear that underlying evidence continues to build and strengthen.
But what of the five new(s)?
First, and most striking, is the global emission reduction potential from demand-side measures: 40-70% across buildings, transport, industry and food sectors by 2050. And with strong benefits for human wellbeing. And with ‘high confidence’ in the underlying evidence.
This moves demand-side policies and innovation up the priority list for climate change mitigation, alongside efforts to decarbonise the energy supply. Demand-side mitigation is achieved through socio-cultural change (e.g., dietary shifts), infrastructure design and use (e.g., public and shared mobility in cities), and end-use technology adoption (e.g., heat pumps in homes). Electrification of transport and heating is the most important demand transformation needed.
Second, both high emitting individuals and status consumption made it through to the ‘Summary for Policymakers’ text as legitimate targets for mitigation policy. This reveals the strength of the evidence pointing out the strong skew in who and where is responsible for emissions, despite the the reactions this can provoke from high-emitting interest groups.
Third, there is now clear evidence of interlinked innovation and policy successes in tackling climate change. In the past decade, the unit costs of solar have fallen by 85%, wind by 55%, and lithium ion batteries by 85%. Related deployments of renewable energy and electric vehicles have accelerated dramatically.
These success stories have two things in common: small unit scales, modularity, and mass manufacturing – which enable rapid learning and cost reductions; and targeted policy support – which combines ‘technology push’ to improve market readiness with ‘market pull’ to create stable demand.
Fourth, climate policies and laws have expanded rapidly in number and scope. By 2020, direct climate laws covered 53% of global emissions in 56 countries. So there is now much more evidence on what works – policies that integrate across multiple domains and scales; regulatory instruments that target technologies and sectors; laws and institutions that provide clarity and direction for low-carbon transitions.
Political and social appetite for much higher carbon taxes, for example, would be sorely tested if pricing mechanisms alone dominate policy thinking
The current body of climate policies and laws reduces global carbon emissions by 5.9 Gt per year, according to one estimate. Conversely, isolated policies have, so far, proven less effective. Political and social appetite for much higher carbon taxes, for example, would be sorely tested if pricing mechanisms alone dominate policy thinking.
Fifth, carbon dioxide removal (CDR) is unavoidable in order to counterbalance hard-to-abate residual emissions. The three main CDR approaches are carbon storage on land, and carbon capture and storage in combination with bioenergy combustion or direct air capture. These latter two technologies are unproven at scale. And land-based CDR faces what the IPCC calls ‘persistent barriers’ that hamper their economic and political feasibility.
Neither nature-based solutions nor negative emission technologies are ‘get out of jail free’ cards. There is no substitute for rapid emission reductions.
Neither nature-based solutions nor negative emission technologies are ‘get out of jail free’ cards. There is no substitute for rapid emission reductions
Where does this all leave us? IPCC assessment cycles are every 6-7 years. The next report will be published around 2030 – the point at which this report says global emissions should be roughly halved. No time to waste.