COP29 showed insufficient progress in climate pledges. Greenhouse gas emissions must decrease by at least 43% by 2030 and 60% by 2035 to meet Paris Agreement goals.
The 29th climate summit in Baku, Azerbaijan brought little progress. Developed countries made a rather vague promise to deliver 300 billion dollars a year to support poorer countries, by 2035. But no progress was made on further emission reductions as proposed texts describing how to implement the phase-out of fossil fuels or achieve the 1.5°C temperature limit were postponed until the next meeting in Bonn in mid 2025.
The two positive mitigation highlights of COP29 were the new 2035 climate pledges of Brazil and the UK that promised to reduce emissions by 59–67% (compared to 2005) and by 81% (compared to 1990) respectively. Both pledges can be considered relatively ambitious, even in comparison with the EU’s potential pledge, which has still not been presented but hovers around 66% (linear trajectory between 2030 and 2050 targets) and 72.5% (linear trajectory between 2030 and proposed 2040 targets).
The meagre mitigation results from COP29 are in stark contrast with two recent UN assessment reports, which show that the world is not coming even close to achieving the 1.5°C temperature rise limit of the Paris Agreement. Both UN Environment (UNEP) and the Framework Convention’s secretariat (UNFCCC) show in their reports that we are currently heading towards a temperature rise of 3°C, unless countries raise ambition and action both in the short-term (pre 2030) and beyond.
UNEP’s Emissions Gap Report tells us that governments must massively increase ambition in current and future climate pledges (Nationally Determined Contributions – NDCs). As things stand, current NDCs put the world on track for a global temperature rise of 2.6–2.8°C this century. Even worse, the policies currently in place are insufficient to meet even these NDCs. If nothing changes, we are heading for a temperature rise of 3.1°C.
In order to stay on track with the Paris Agreement, countries should collectively reduce greenhouse gas emissions by at least 43% by 2030, and by 60% by 2035, compared to 2019 emissions levels. This will require a global mobilisation on a scale and pace never seen before. But it does, for the moment at least, remain technically possible. Governments can deliver the cuts needed by investing heavily in solar and wind energy, in forests, in reshaping the buildings, transport and industry sectors, and more – all backed by a whole-of-government approach, a new global financial architecture and strong private sector action.
The Emissions Gap Report shows that the techno-economic emission reduction potential based on existing technologies and at costs below US$200 per ton of carbon dioxide equivalent remains sufficient to bridge the emissions gap in 2030 and 2035. But this will require overcoming formidable policy, governance, institutional and technical barriers as well as an unprecedented increase in the support provided to developing countries along with redesigning the international financial architecture.
To do so, we need to break the trend and start cutting emissions as soon as possible. Currently, global greenhouse gas emissions are continuing to rise and have reached a new record of 57.1 Gigatonnes, a 1.3 per cent increase from 2022 levels. This increase is above the average rate for the decade preceding the COVID-19 pandemic, when greenhouse gas emissions growth averaged 0.8 per cent per year.
A continuation of the mitigation effort implied by current policies is estimated to limit global warming to a maximum of 3.1°C over the course of the century. The full implementation and continuation of the level of mitigation effort implied by unconditional or conditional NDC scenarios lowers these projections to 2.8°C and 2.6°C, respectively. All with at least a 66 per cent probability.
Under these three scenarios, central warming projections indicate that the chance of limiting global warming to 1.5°C would be virtually zero. By mid-century, they imply global warming of well above 1.5°C and with up to a 1-in-3 chance that warming will already exceed 2°C by then. Warming is also expected to increase further after 2100 as CO2 emissions are not yet projected to reach net-zero levels under these scenarios.
On top of the 2030 climate targets, over 100 countries, covering over 80 per cent of global greenhouse gas emissions, have adopted net-zero pledges either in law, in policies or in high-level announcements. Overall, however, little progress has been made towards implementing these pledges.
Specifically, if action in line with 2°C or 1.5°C pathways were to start in 2024, then global emissions would need to be reduced by an average of 4 or 7.5 per cent respectively every year until 2035. If enhanced action that goes beyond current unconditional NDCs is delayed until 2030, then the required annual emission reductions rise to an average of 8 or 15 per cent to limit warming to 2°C or 1.5°C, respectively. Immediate action matters: temperature projections based on the conditional NDC scenario are 0.5°C lower than those based on existing policies.
The only scenario that gets closer to the temperature goal of the Paris Agreement is the most optimistic scenario, which assumes that all the most stringent pledges currently made by countries – in other words the conditional NDCs and all net-zero pledges, including those made as part of long-term low-emissions development strategies – are fully implemented. This scenario is estimated to limit warming over the course of the century to 1.9°C. This is also the only pledge-based scenario in which global warming is stabilised over the course of this century.
