What are “nationally determined contributions” to curb climate change?

TODAY JOE BIDEN, America’s president, is playing host to 40 world leaders in a virtual climate summit. He kicked it off with a plan to cut America’s greenhouse-gas emissions in half by 2030, compared with their levels in 2005. That is nearly twice the reduction promised by Barack Obama in 2015 (and later cancelled by Donald Trump). Other countries are announcing similar pledges, known as “nationally determined contributions” (NDCs), which are a crucial part of the global framework to tackle climate change. But what exactly are they?

The concept of NDCs was first introduced at COP19, the UN’s climate summit in Warsaw in 2013. At first they were vague. Governments that were “ready to do so” were invited to submit non-binding climate pledges to the United Nations Framework Convention on Climate Change (UNFCCC) by the first quarter of 2015. Crucially, these pledges were to be formulated by countries based on their own priorities, needs and prospects. This flexibility was meant to overcome the problems that had plagued the Kyoto Protocol, the UNFCCC’s first accord, which came into force in 2005. That had committed only developed countries, such as Britain, to cutting their emissions. Developing countries, including China—which, by 2006, was the largest emitter of carbon dioxide in the world—were not included. The arrangement was deemed to be too rigid and unfair. America ultimately refused to ratify it; Canada withdrew in 2011.

A tricky balancing-act ensued: NDCs needed to contain enough wriggle room to make them politically viable, but still meaningfully lower emissions. Hashing out what NDCs should include required careful negotiation. It was decided, at a summit in Lima in 2014, that the poorest and most vulnerable countries—which contribute the least to climate change but will suffer its effects most acutely—needed to commit only to developing in a low-carbon way. All other countries, developed and developing alike, were obliged to make plans to reduce their emissions, though the mechanisms (such as increased use of renewable energy, or carbon sequestration) and speed with which they did so could vary. Countries were also encouraged, but not required, to outline measures to help the world adapt to climate change, including financial support from rich countries to poor ones.

When countries signed up to the Paris agreement, negotiated at COP21 in 2015, they committed to a common goal: keeping the world’s average temperature to “well below” 2°C above pre-industrial levels, and “pursuing efforts to limit it to 1.5°C”. They also promised to produce NDCs to show how they might get there. These laid out countries’ targets for reducing emissions over a clearly articulated period of time and the steps they would take to achieve their goals. Letting countries (mostly) make their own decisions on emissions meant that many more signed up than might have done under a more prescriptive accord. Big emitters such as China and India submitted themselves to scrutiny for the first time. But such flexibility meant that no country made commitments large enough to meet the Paris agreement’s goals: the first tranche of NDCs was expected to lead to global warming of around 3°C. Accordingly, the Paris agreement also outlined a “ratchet mechanism”, by which countries were meant to increase the ambition and scope of their NDCs every five years.

Countries were meant to submit their updated NDCs ahead of the COP26, the UN’s next climate summit, which was scheduled to take place in Glasgow in November 2020. That plan, like so many others, was scrambled by the covid-19 pandemic. COP26 was pushed to November 2021. Only a handful of countries have strengthened their targets. Britain has promised to reduce its greenhouse-gas emissions by at least 68% by 2030, compared with 1990 levels. The 27 members of the European Union have pledged to reduce their emissions by “at least 55%” across the same period. China has proposed, but not formally submitted, a new target of reaching carbon neutrality before 2060. In announcing America’s new emissions target Mr Biden hopes to galvanise those countries lagging behind. They include the likes of Australia, Brazil and Russia, which have yet to submit higher targets.

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