The world is on track for a comprehensive global treaty on climate change for the first time after agreement was reached at talks in Durban, South Africa in the early hours of Sunday morning.
Negotiators agreed to start work on a new climate deal that would have legal force and, crucially, require both developed and developing countries to cut their carbon emissions. The terms now need to be agreed by 2015 and come into effect from 2020.
"I salute the countries who made this agreement. They have all laid aside some cherished objectives of their own to meet a common purpose – a long-term solution to climate change," said Christiana Figueres, the United Nations climate chief.
Chris Huhne, the UK's energy and climate secretary, said the deal would ensure the European Union's efforts to tackle global warming were matched by others. "We know that we are working very hard on this, but we need to be sure that other countries are working just as hard – that's very important for our industry and our competitiveness," he said.
But Huhne also acknowledged that the hard work was only beginning, because following the agreement struck in Durban, governments face four gruelling years of horse-trading over how far and how fast each country should cut its carbon, in order to flesh out the bones of the deal.
Two weeks of talks — the last 60 hours of which was a single marathon negotiating session, with officials holed up in a conference centre through three nights with scarcely a break — ended with a surprise decision struck during a tea break just before dawn on Sunday.
A small huddle of key ministers were ordered to meet for 20 minutes and thrash out their differences. With tempers rising and the talks minutes from being abandoned, the chair, South African foreign minister Maite Nkoana-Mashabane, ordered China, India, the US, Britain, France, Sweden, Gambia, Brazil and Poland to meet in a small group or "huddle". Surrounded by nearly 100 delegates on the floor of the hall, they talked quietly among themselves to try to reach a new form of words acceptable to all.
The agreement – dubbed the "Durban platform" – is different from the other partial deals that have been struck during the past two decades, with developing countries, including China, the world's biggest emitter, agreeing to be legally bound to curb their greenhouse gases. Previously, poorer nations have insisted that they should not bear any legal obligations for tackling climate change, whereas rich nations – which over more than a century have produced most of the carbon currently in the atmosphere – should.
Another first is that the US, the second biggest emitter, also agreed that the new pact would have "legal force" – a step it flirted with in 1997 with the Kyoto protocol, but abandoned as Congress made clear it would never ratify that agreement.
All of the world's biggest economies and emitters already have targets to cut emissions between now and 2020, when the new deal would come into force.
But those targets are voluntary, not legally binding. This is a crucial difference for the EU and many others, who fear that voluntary targets are too easy to wriggle out of.
However, the deal did little to address the scale of emissions cuts needed, and environmental groups said this was a huge failing.
Keith Allott, head of climate change at WWF-UK, said: "Governments have salvaged a path forward for negotiations, but we must be under no illusion — the outcome of Durban leaves us with the prospect of being legally bound to a world of 4C warming. This would be catastrophic for people and the natural world. Governments have spent crucial days focused on a handful of specific words in the negotiating text, but have paid little heed to repeated warnings from the scientific community that much stronger, urgent action is needed to cut emissions."
Lord Stern, former World Bank chief economist and author of the landmark 2006 review of the economics of climate change, said: "The outcome of the summit is a modest but significant step forward. The decision to move towards a unified system, with all countries having some form of legal commitments, removes an important obstacle and could allow, for example, the US to play a more participative and constructive role in the future."
The agreement reached also ensured that developing countries will soon begin to gain access to billions of pounds in finance from the rich world to help them move to a green economy and cope with the effects of climate change.