Running out of time, not running out of options

21 Mar 2023

Planning and Environment

IPCC’s clarion call for hugely accelerated net zero policies and development.

Yesterday the Intergovernmental Panel on Climate Change (“IPCC”) published one of its shortest, but most important, reports: a 36-page Synthesis Report, which draws together conclusions and recommendations from its detailed reports produced over the last six-year reporting cycle. It does not contain any new science. Rather, it sets out very clear conclusions and priorities, based on the science in its previous reports, in non-technical language aimed at an audience of policymakers.

The Synthesis Report is important for decision-makers across central and local government, as well as for those making choices about promotion of and investment in net zero development. Its key message, in the words of the IPCC chair at the press conference announcing the report, is that “we are walking when we should be sprinting”. Deep, rapid, sustained, and immediate reductions in greenhouse gas emissions are needed to avoid dangerous and irreversible consequences for human and natural systems. A wide range of co-benefits would accompany rapid and sweeping emission reduction, especially in terms of air quality and public health. The Synthesis Report provides a blueprint for the necessary swift action: a “survival guide for humanity”.

Several key themes emerge from the report, but all are linked by the need for immediate, sustained, and coordinated action.

Key messages

  • Even the smallest increments of warming matter. Every fraction of a degree will increase the severity and frequency of dangerous climate impacts. It would be perilous and unjust to overshoot 1.5oC

The IPCC predicts catastrophic and irreversible loss and damage if we overshoot 1.5oC of warming, even if we ultimately manage to bring temperatures back down below that level in the second half of the 21st century, for example by sucking greenhouse gas emissions out of the atmosphere. The modelling for trajectories which see temperatures return to less than 1.5oC of warming by 2100 after a period of overshoot predict a range of dangerous impacts, some of which will be permanent, including rising sea levels, species loss, and loss of food and water security. Moreover, the IPCC cannot be confident that a return to less than 1.5oC of warming would even be possible, because overshoot would bring with it an increased risk of additional warming via feedback loops caused by wildfires, widespread mortality of trees, drying of peatlands, and thawing of permafrost.

To mitigate these impacts, the report is clear that even the smallest increments of warming matter. Every fraction of a degree will increase the severity and frequency of floods, droughts, storms, heatwaves, and other extreme weather events, and it is people living in countries and regions which have contributed the least to climate change who will be most vulnerable to its effects. Already, over the decade between 2010 and 2020, deaths from floods, droughts, and storms were fifteen times higher in areas which are highly vulnerable to the effects of climate change, and almost half the world’s population currently live in areas of high vulnerability. Rapid emission reductions are therefore a matter of climate equity, since the impact of overshoot will hit the least responsible nations hardest.

  • Rapid investment at scale in renewables is needed. Existing and planned fossil fuel development already consumes a 2°C carbon budget. Carbon capture technologies are not a magic bullet.

The report is clear that a rapid transition away from fossil fuels and towards renewable energy is the best and most reliable way to limit warming. This means investing at scale in renewable energy and it also means bringing an immediate end to new fossil fuel developments. The report states that “projected cumulative future CO2 emissions over the lifetime of existing and planned fossil fuel infrastructure […] are approximately equal to the remaining carbon budget for limiting warming to 2°C.”

The report makes clear the dangers of relying on future speculative carbon capture and storage (“CCS”) technologies, stating that “Implementation of CCS currently faces technological, economic, institutional, ecological, environmental and socio-cultural barriers. Currently, global rates of CCS deployment are far below those in modelled pathways limiting global warming to 1.5°C to 2°C.”

It also warns against over-reliance even on natural forms of carbon-dioxide removal (“CDR”), such as reforestation and peatland restoration, while acknowledging that these have an important role to play.

  • Net zero policies work! They have avoided emissions. More policies, securing deep and rapid reductions, are desperately needed.

One of the most important figures released with the Synthesis Report is Figure 5(a):

We are currently in the red: implemented policies have us on track for warming of 3.2oC, with a range of 2.2oC to 3.5oC. We need to be in the blue. There is therefore currently a huge policy gap. But, the IPCC is clear: policymakers have the tools available to them to make the transition away from fossil fuel dependency and to secure the necessary greenhouse gas reductions. One of the most hopeful parts of the Report is: “multiple lines of evidence suggest that mitigation policies have led to several Gt CO2-eq yr-1 of avoided global emissions”, relative to the level of emissions that would have occurred with no policy interventions. In other words, the actions of governments, policymakers, and corporations do have the power to move the needle on global heating and they already have the tools available to them to decarbonise the economy. However, this transition must not be put off.

  • Climate finance has a vital role to play and investment comes with many co-benefits.

There needs to be a rapid and sustained increase in finance for climate initiatives. The report estimates that something in the region of three to six times the current level of climate finance is required. However, it is clear that sufficient global finance is available to make this happen but that this finance is currently misaligned. Both public and private finance flows for fossil fuels are still greater than those for climate adaptation and mitigation.

A shift in the allocation of global financial resources would not only help to prevent potentially catastrophic climate impacts, but also bring with it a host of co-benefits. The report highlights the public health benefits of mitigation measures to reduce air pollution, facilitate active travel and incentivise a shift to more sustainable diets. Moreover, it estimates that the economic benefits for human health from air quality improvement alone could be of the same order of magnitude as mitigation costs, or potentially even larger, without even taking into consideration the wider economic benefits of avoiding climate breakdown.

Read in full the Synthesis Report Summary for Policymakers.

Estelle Dehon KC is instructed in a number of matters concerning climate change, including advising local authorities on net zero planning policies; engaging with developers promoting net zero development; a High Court challenge against a proposed new Cumbria coal mine; a Court of Appeal challenge to the expansion of Bristol Airport and the Supreme Court case of Finch, which will consider the correct approach to assessing the greenhouse gas emissions of fossil fuel development. Estelle’s overview of the IPCC’s Sixth Assessment first report is here.