Climate activists are urging strong action by delegates arriving in Belem for the UN Climate Change Conference (COP30).Photography: Eraldo Perez/AP/Alamy
It has been ten years since Laurent Fabius, then French Foreign Minister, announced the United Nations Twenty-First Conference of the Parties on Climate Change (COP21), giving rise to the 2015 Paris Climate Agreement. It is an incomplete agreement, especially since the initial commitments it established were woefully inadequate. But it has set an important goal: avoiding planetary-scale environmental, economic and social disruption by curbing greenhouse gas emissions and limiting global warming to no more than 2 degrees Celsius – ideally 1.5 degrees Celsius – above pre-industrial levels. To this end, the countries agreed to a pledging and iterative review process that would, in theory, build confidence along with progress and momentum.
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As government representatives gather in Belém, Brazil, for the 30th session of the Conference of the Parties, it is reasonable to ask whether this process is delivering what it promised. Globally, greenhouse gas emissions have increased by 10% since 2015, reaching a new peak equivalent to the emission of about 53 billion tons of carbon dioxide last year.
As average global temperatures continue to rise, the world is experiencing long-expected impacts: more severe wildfires, storms, floods and droughts. Just last month, Derek Manzello, a researcher at the US National Oceanic and Atmospheric Administration, and his colleagues reported that an unprecedented marine heatwave in 2023 has pushed a pair of iconic corals that have served as primary reef builders off the coast of Florida for the past 10,000 years to “functional extinction” (D. B. Manzello et al. sciences 390361-366; 2025). Researchers at Imperial College London estimate that global warming made Hurricane Melissa, the monster storm that tore through the Caribbean last month, Four times more likely to happen.
Many countries are taking action, whether through mitigation measures, such as using more clean energy, or through financial investments to adapt and prepare for a changing climate. There is no doubt, as our latest news shows, that the engines of a low-carbon economy are accelerating around the world – despite anti-climate policies being implemented in the United States, the world’s largest economy and second-largest emitter, which withdrew from the Paris Agreement.
The UN Climate Secretariat in Bonn, Germany, which monitors the state of national climate policies, has found signs of progress: Countries are working on stronger and more comprehensive climate action plans, called Nationally Determined Contributions (NDCs), compared to those drafted in 2020, the last time countries had to submit them. Three-quarters of the 64 plans analyzed by the Climate Secretariat address adaptation and resilience (see go.nature.com/56hj7). Nearly 90% of the plans submitted set comprehensive, economy-wide emissions targets.
Warning signs
But the UN report also sounded the alarm, warning that commitments were still too few and too weak to achieve the Paris goals. This remains true even when considering targets that have been announced – but not formally submitted as NDCs – by two of the world’s largest emitters: China and the European Union.
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Adding everything up, official commitments and announced targets would reduce emissions by about 10% from 2019 levels by 2035, according to the UN climate report. This is far short of the roughly 60% reductions needed to keep the world on a viable path to limiting temperature rise to no more than 1.5 degrees Celsius this century. Of course, just setting a target does not mean that any country will achieve it.
Other issues needing attention include climate finance. Under the Paris Climate Agreement, low- and middle-income countries have agreed for the first time to be subject to the same legally binding agreement as richer countries, which will lead the way and then help provide cash and technical assistance in both mitigation and adaptation efforts.
Low-income countries are doing their part, making commitments and formulating detailed sustainable development plans – but the long-promised flow of climate finance has been sorely lacking. Although the OECD estimates that private and public financing combined now exceeds $100 billion, countries have already set a new target of mobilizing $300 billion annually by 2035, with an ambitious target of $1.3 trillion. The next question is how to achieve this goal, and this will constitute a major agenda item in Belem.
Increasingly, delegates and observers are questioning whether the COPs – which now attract more than 50,000 people, often for separate climate-related events held at the same time as the COP – are the right place to accelerate climate action. In the corridors of the COP30, there will be talk of reform – with the UN’s finances under pressure, one idea is to merge the body that organizes climate COPs within the UN Environment Agency (UNEP) to help cut costs.
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The merits of this and other proposals are for another day. For now, the reality is that the COP is the only space where representatives around the world can and should discuss complex climate issues, says Ani Dasgupta, president of the World Resources Institute, an environmental research and policy center based in Washington, DC. In fact, if reformers were to scrap the whole process and start over, Dasgupta says, they would almost certainly create something very similar to the current COP process.
More than anything else, a strong signal is needed that governments will stay the course, despite growing political headwinds, at the UN Climate Change Conference (COP30). The scientists’ message is clear: everyone needs to act quickly. Governments must find ways to strengthen their commitments and continue the hard work to make them a reality.
The COP30 has been called the “Executive COP” for good reason. The rules and framework of the agreement have been established. Mechanisms and facilities have been created to deal with everything from climate finance and adaptation, to market-based mechanisms and damages from the inevitable impacts of global warming, known as losses and damages. Now it’s a matter of follow-up. Everyone at the UN Climate Change Conference (COP21) in Paris knew their commitments fell far short of what was needed – but the Paris Agreement represents a promise to do more, faster and better, in the future. Once again, as always, the future is here.