The US will hold a climate summit of the world’s major economies early next year, within 100 days of Joe Biden taking office, and seek to rejoin the Paris agreement on the first day of his presidency, in a boost to international climate action.
Leaders from 75 countries met without the US in a virtual Climate Ambition Summit co-hosted by the UN, the UK and France at the weekend, marking the fifth anniversary of the Paris accord. The absence of the US underlined the need for more countries, including other major economies such as Brazil, Russia and Indonesia, to make fresh commitments on tackling the climate crisis.
Biden said in a statement: “I’ll immediately start working with my counterparts around the world to do all that we possibly can, including by convening the leaders of major economies for a climate summit within my first 100 days in office … We’ll elevate the incredible work cities, states and businesses have been doing to help reduce emissions and build a cleaner future. We’ll listen to and engage closely with the activists, including young people, who have continued to sound the alarm and demand change from those in power.”
He reiterated his pledge to put the US on a path to net zero carbon emissions by 2050, and said the move would be good for the US economy and workers. “We’ll do all of this knowing that we have before us an enormous economic opportunity to create jobs and prosperity at home and export clean American-made products around the world.”
What does net zero mean?
Net zero emissions springs from the Paris agreement, though the goal was not made explicit in the treaty’s text. World leaders set the 2C limit, and the aspirational limit of 1.5C, at Paris based on advice from the Intergovernmental Panel on Climate Change, the leading body of the world’s climate scientists, which has over years worked out that 2C was the threshold of safety, beyond which the ravages of climate breakdown were likely to become catastrophic and irreversible. Even at 1.5C, many low-lying areas could flood from sea level rises and storm surges.
After Paris, the IPCC was asked to advise further on the emissions cuts needed to stay within those limits. Building on its previous findings, the world’s climate science authority established in 2018 that emissions would have to reach zero around mid-century, and that this could be achieved if emissions were halved in the next decade or so.
That clear scientific backing helped to establish net zero emissions by 2050 as the standard that must be achieved.
Net zero emissions means reducing emissions as far as possible, and balancing out whatever remains by increasing carbon sinks, for instance by growing trees or restoring wetlands and peatlands. Phasing out coal, switching to renewable energy, the more efficient use of energy, and moving to electrified transport will all be key. Nuclear power may also play a role, and some countries such as China and France are investing in a new generation of reactors. Carbon capture and storage technology, by which carbon dioxide from large sources as gas-fired power plants or industrial units is captured at source, liquefied and piped into large underground chambers, such as depleted oilfields, is also likely to be needed, in varying amounts according to different analyses.
Some scientists believe we also need to start to capture carbon dioxide directly from the air. One method of doing this involves crushing up limestone rocks to spread chalk dust on fields. The limestone absorbs carbon, and the dust improves the soil.
António Guterres, the UN secretary general, said: “It is a very important signal. We look forward to a very active US leadership in climate action from now on as US leadership is absolutely essential. The US is the largest economy in the world, it’s absolutely essential for our goals to be reached.”
Donald Trump, whose withdrawal of the US from the Paris agreement took effect on the day after the US election in November, shunned the Climate Ambition Summit. Countries including Russia, Saudi Arabia and Mexico were excluded as they had failed to commit to climate targets in line with the Paris accord. Australia’s prime minister, Scott Morrison, had sought to join the summit but his commitments were judged inadequate, and an announcement from Brazil’s president, Jair Bolsonaro, of a net zero target just before the summit was derided as lacking credibility.
The Climate Ambition Summit failed to produce a major breakthrough, but more than 70 countries gave further details of plans to reduce greenhouse gas emissions in line with the Paris agreement goal of limiting temperature rises to well below 2C above pre-industrial levels, with an aspirational 1.5C limit.
Many observers had hoped India might set a net zero emissions target, but its prime minister, Narendra Modi, promised only to “exceed expectations” by the centenary of India’s independence in 2047. China gave some details to its plan to cause emissions to peak before the end of this decade but stopped short of agreeing to curb its planned expansion of coal-fired power.
The UK pledged to stop funding fossil fuel development overseas, and the EU set out its plan to reduce emissions by 55% by 2030, compared with 1990 levels.
Alok Sharma, the UK’s business secretary, who will preside over UN climate talks called Cop26 next year, said much more action was needed. “[People] will ask: have we done enough to put the world on track to limit warming to 1.5C and protect people and nature from the effects of climate change? We must be honest with ourselves – the answer to that is currently no,” he said.
When Biden’s pledge to bring the US to net zero emissions by 2050 is included, countries accounting for more than two-thirds of global emissions are subject to net zero targets around mid-century, including the EU, the UK, Japan and South Korea. China has pledged to meet net zero by 2060, and a large number of smaller developing countries have also embraced the goal.
What are NDCs (nationally determined contributions under the Paris Agreement)?
Under the 2015 Paris agreement, nations agreed a legally binding target of holding global temperature rises to well below 2C above pre-industrial levels, with an aspirational limit of 1.5C.
To stay within those legally binding temperature limits, cuts to greenhouse gases would be key. But the long history of climate negotiations since 1990 had left a legacy of distrust, and some countries were unwilling to commit to stringent emissions cuts if they feared others were not pulling their weight. So under the accord, governments signed up instead to non-binding national plans – called nationally determined contributions, or NDCs – on cutting or, in the case of poor countries, curbing the growth of their emissions by about 2030.
The NDCs that countries presented in 2015 were inadequate to meet the Paris goals, however, and if allowed to stand would result in warming of about 3C, which would cause devastation around the world.
For that reason, the accord also contains a ratchet mechanism by which every five years countries must submit fresh NDCs that put them closer to the Paris goals. The first deadline for new NDCs is 31 December this year.
Some countries will meet the deadline: scores of developing countries have already submitted their plans. Bigger economies have been slower to do so, but several are now imminent.
The UK has announced its NDC, with an emissions cut of 68% by 2030 compared with 1990 levels, a marked improvement on its 2015 NDC containing only a 53% cut, though climate experts said a more ambitious target would have been economically feasible.
The EU is to discuss its proposed target of a 55% emissions cut this week. Japan has also produced an NDC, but is under pressure to revise it. China is working on its plans, after president Xi Jinping announced in September that Chinese emissions would peak by 2030.
The US will miss the deadline, but president-elect Joe Biden has committed to rejoining Paris as soon as possible when he takes office, so presenting a new NDC is likely to be a top priority.
The task for the next year, before the Cop26 conference in Glasgow next November, will be to encourage all the world’s remaining countries – including oil-dependent economies such as Russia and Saudi Arabia – to sign up to long-term net zero targets, and to ensure that all countries also have detailed plans for cutting emissions within the next decade.
Those detailed national plans, called nationally determined contributions (NDCs), are the bedrock of the Paris agreement, setting out emissions curbs by 2030. Current NDCs, submitted in 2015, would lead to more than 3C of warming, so all countries must submit fresh plans in line with a long-term goal of net zero emissions. The US will be closely watched for its plans.
Nathaniel Keohane, a senior vice-president at the Environmental Defense Fund, said: “The [Climate Ambition] Summit captured and reflected the momentum of recent months, but didn’t push much beyond it. The world is waiting for Biden to bring the US back into the Paris agreement, and will be looking for how ambitious the US is willing to be in its NDC.”