What the IPCC report means for global action on 1.5°C

Urgent action is needed to evolve efforts to address climate change and the degradation of nature.

Expert comment Published 22 March 2023 Updated 15 September 2023 3 minute READ

The landmark 2015 Paris Agreement gave rise to international consensus to keep global warming to ‘well below 2°C above pre-industrial levels’ while ‘pursuing efforts to limit the temperature increase to 1.5°C’.

But the release of the Intergovernmental Panel on Climate Change (IPCC) AR6 synthesis report this week lays out in stark terms how close the world is to missing the 1.5°C target, what it means for society and what can still be done to avoid it.

Since the signing of the Paris Agreement, the importance of limiting climate change to the more ambitious 1.5°C target has become imperative among the climate community. Climate change is impacting societies globally but warming beyond 1.5°C will prove disastrous to the over 3 billion people who live in places highly vulnerable to climate change.

It’s becoming increasingly clear how, in a world with warming beyond 1.5°C, the effects of climate change can quickly cascade from an environmental risk to an economic threat, such as if prolonged drought leads to a failed harvest, reducing availability across supply chains and increasing prices. The impact of climate change can also multiply threats and reduce societal resilience to pandemics or conflicts, or can trigger climate tipping points, such as the collapse of the Greenland ice sheet or coral reefs.

The report’s findings are not easy reading yet are not surprising. It highlights that global surface temperature rose to roughly 1.09°C higher in the period between 2011 and 2020 compared to 1850 and 1900 and that projected global emission reductions by 2030 – if countries follow their targets agreed upon prior to COP26 – are not enough to ensure warming remains under 1.5°C.

The report also states that it is ‘likely’ that warming will exceed 1.5°C in the 21st century. To avoid this, greenhouse gas emissions need to be approximately halved from 2019 levels between 2030 and 2035 before approaching net-zero emissions by 2050.

That is not to say that limiting warming to 1.5°C is no longer possible. The IPCC’s report highlights that many of the technologies needed to remain below 1.5°C exist and in many cases are cheaper than using fossil fuels. What is lacking is political will which has not been sufficient enough so far to enable deep, transformative decarbonization. 

What is lacking is political will which has not been sufficient enough so far to enable transformative decarbonization. 

The IPCC emphasizes the need for ‘rapid, deep and, in most cases, immediate greenhouse gas emissions reductions.’ But, at current emissions levels, the carbon budget for 1.5°C – or the amount of greenhouse gases that can be released into the atmosphere associated with a certain temperature rise – will be spent in the next decade.

Indeed, the closing window of opportunity to limit climate change to 1.5°C has sparked public debate on its feasibility. In November 2022, The Economist ran a briefing  ‘The world is going to miss the totemic 1.5°C target’ while, last week, the Financial Times asked, ‘Is 1.5°C still realistic?’.   

The question of whether the 1.5°C target is still viable is complex and difficult. But the very act of debating the feasibility of the 1.5°C target will, circuitously, create conditions that affect the political will to achieve it. 

The context in which breaching the 1.5°C limit is spoken about, and how it is defined, is important. The most accurate indicator of warming would be to take a long term average of global temperatures over many years – or even decades. But there is also likely to be debate when global average temperatures exceed 1.5°C in a calendar year.

One other way in which to measure warming is to look at the concentrations of atmospheric greenhouse gas in the atmosphere rather than the absolute average temperature. Currently, none of these limits have been passed, but some narratives already highlight the loss of the 1.5°C limit because of assumptions that it is not politically or economically feasible to reduce emissions enough.

Conceding that 1.5°C is lost may either galvanize the incumbent system or encourage reliance on unproven technologies.

Conceding that 1.5°C is lost may either galvanize the incumbent system to pursue transformative energy – and industry – decarbonization. Alternatively, the shock of the loss of 1.5°C may encourage governments, or empower climate deniers, to argue for reliance on risky, unproven technologies such as overreliance on carbon capture storage or even solar radiation modification technologies. Equally, it may be used to show that decarbonization is not practical and society needs to adapt to a changed climate.

Recent analysis by the Institute for Public Policy Research and Chatham House typifies the above example as a broader dynamic, or ‘doom loop’, that will emerge as the climate crisis intensifies. In this new era, dealing with the worsening consequences of climate change may swamp the capacity of governments to take the transformative action on the root cause of the crises itself.

But the inverse dynamic is also possible. Global, transformative action taken today reduces the consequences to society in the short and long run, not only limiting the severity of extreme climate events, but also its cascading economic and security impacts, as well as curtailing the risk of a delayed and disorderly transition for society, which allows yet more transformative action to be taken in the future.

Beyond this, there are also wide-ranging co-benefits to mitigating climate change. This includes the restoration of natural ecosystems, air quality and overall societal health. Transformative action may incur an up-front cost to society today, with the IPCC estimating up to six times current annual investment for 1.5°C aligned scenarios, but the long-term economic benefits to society are profound.

We are entering a new era of consequences of climate change.

The IPCC report demonstrates that we are entering a new era of consequences of climate change and conversations about the feasibility of 1.5°C are unlikely to go away. Indeed, they are likely to resurface time and again at critical junctures over the next 12 months leading up to COP28 this year in Dubai.

Urgent action is needed to evolve efforts to address climate change and the degradation of nature. The challenge for the business, finance and policymakers is identifying how to use this critical time to course-correct current trends in emissions and take immediate action in order to advance positive and transformative change.