The UN says an agreement at arguably the most important climate summit in 20 years will put us on track to limit warming to 2 °C. Others say this is fantasy

Do climate treaties work?

Official view: The Paris Protocol will build on the success of Kyoto

International efforts to tackle climate change began at the Earth Summit in Rio de Janeiro in 1992, leading to the 1997 Kyoto Protocol. Earlier this year, the branch of the United Nations that oversees climate negotiations, the UNFCCC, declared the protocol had proved that climate agreements work.

The protocol required that, by 2013, industrialised countries cut their greenhouse gas emissions by an average of 5 per cent relative to 1990 levels. While some failed, most beat their targets. Their collective emissions fell by about 23 per cent. “The Kyoto Protocol was a remarkable achievement in many ways,” Christiana Figueres, head of the UNFCCC, has said. “It clearly played an important role in catalysing this promising trend, which has led to a collective and very welcome ‘over-achievement’.”


“The Kyoto Protocol was a remarkable achievement – it pioneered concepts we take for granted today”

The protocol also “put in place pioneering concepts, flexible options, practical solutions and procedures for accountability that we often take for granted today”, Figueres said.

Critics’ take: Paris deal will have same weaknesses as failed Kyoto protocol

Developing countries were not required to make cuts under the Kyoto Protocol. A number of industrialised countries – including the US, then the biggest polluter – didn’t sign up and Canada withdrew in 2011.

The fall in emissions in the 36 industrialised countries that stuck with it has been far outweighed by increased emissions in China and elsewhere. Global emissions have soared, and the level of carbon dioxide in the atmosphere – the factor that directly affects the climate – is increasing faster than ever.

What’s more, not much of the fall in industrialised countries can be attributed to the protocol. Much of it was due to manufacturing shifting to China, and to the financial crisis of 2008. The final form of the Paris deal is yet to be decided, but it’s clear it will suffer from many of the same problems as its predecessor.

Read an in-depth version of this story: Do UN climate change treaties ever work?

Can a new deal be reached in Paris?

Official view: A deal looks likely – THE political will is there

The countries that signed up to the 1992 climate convention – the Conference of the Parties or COP in diplomatese – started meeting every year in 1995. The third COP meeting established the Kyoto Protocol, to run until 2012.

The infamous 2009 meeting in Copenhagen failed to extend the protocol beyond 2012. A major sticking point, as ever, was trying to get industrialised countries to sign up to bigger cuts when developing nations were allowed to increase their emissions.

Efforts in the last few years shifted from extending Kyoto to setting up a whole new climate treaty to run from 2020 to 2030. Instead of trying to impose targets on nations, individual countries have instead been asked to declare what they are prepared to do: their “Intended Nationally Determined Contributions”.

Negotiators say the INDCs have exceeded expectations, and they are optimistic that a deal can be agreed at COP21 in Paris. Unlike with previous meetings, they say, there is real political momentum.

Critics’ take: whether or not a deal is reached, it won’t be enough

For many, just getting nearly 200 countries to sign a climate deal would make the Paris meeting a success. And they have a point. There are still issues that could scupper any deal, such as developing countries seeking compensation from developed nations for losses and damage related to climate change.

The ultimate aim, however, is supposed to be to limit global warming to 2 °C – the questionable figure chosen as a “safe” limit. Figueres has said that any deal in Paris will not be enough to achieve this. But she insists that Paris will put us “on a pathway” to 2 °C, or even better: 1.5 °C. Yet to have a chance of staying below 2 °C, total emissions after 2011 can’t exceed 1000 gigatonnes of CO 2 . The UNFCCC’s own figures show that we will have burned through that budget by around 2036, even if countries stick to their INDCs.

Read an in-depth version of this article: Can a deal be reached at the the UN’s meeting?

Will countries make bigger cuts after Paris?

Official view: Paris is just the start. The aim is to ratchet up the action in the coming years

Any deal signed in Paris will establish a floor rather than a ceiling for cuts to greenhouse gas emissions by 2030, Figueres says.

The idea is that every five years or so, countries will be asked to review their targets to see if they can do more. The details have yet to be agreed, but it would have to be entirely voluntary to win support.

However, as the US has argued, clean energy technology is advancing, its cost is falling and political will to take action is increasing. For example, leaders of US and China have recently come together to back action on climate change. Many countries may be prepared to do more come 2020 or 2025.

The G8 countries and a few others have already said they will cut emissions by 80 per cent by 2050 – the minimum required to meet the 2 °C target. More countries are likely to join them.

Critics’ take: Any ratcheting up will be too little, too late to stay below 2 °C

Back in 1997, some hailed the Kyoto Protocol as a step towards the 2 °C goal. Nearly two decades on, we have run out of time.

Even if every country took action in earnest today, extremely drastic – and politically unpalatable – measures would be required to stay below 2 °C, as Kevin Anderson of the Tyndall Centre for Climate Change Research in the UK and others have shown.

The cuts on the table for Paris will not even stop global emissions growing. If we delay until 2020 or 2025, the time frame will be even more unrealistic.

“The cuts on the table for Paris will not even halt the rise in global greenhouse gas emissions”

As for the countries that have committed to an 80 per cent cut by 2050, none is on course to achieve it. The UK and Germany are going to miss 2020 targets for renewable energy. This does not bode well for tougher cuts in other sectors, such as agriculture.

Read more: Will nations make bigger cuts after Paris?

Can we keep global warming to safe levels?

Official view: The Paris agreement will at least keep warming below 4 °C

A series of recent analyses suggest that the proposals on the table for Paris would put us on course to keep warming below 3.7 °C – perhaps as low as 2.7 °C if rapid emissions cuts can be sustained well beyond 2030.

That may be warmer than 2 °C, but it would still be a significant achievement – and far better than the alternative. Without efforts to cut emissions, we would be heading for a world well over 4 °C warmer by 2100, with potentially catastrophic consequences on the climate and our lives.

If the Paris Protocol succeeds in increasing the ambition after it comes into effect, we may be able to get even closer to 2 °C. And if we find ways to suck CO 2 out of the atmosphere on a vast scale – achieving so-called negative emissions – there is still a chance we can limit warming to 2 °C or perhaps even lower.

Critics’ take: Global temperatures could rise 4 °C even if the Paris Protocol is wildly successful

By failing to cut emissions, we are taking a huge gamble. Even if we somehow stick to the target budget of 1000 gigatonnes of CO 2 , computer models suggest the resulting warming in 2100 could range from 1.3 °C to 3.9 °C – and keep climbing to 6 °C by 2200 in the worst case. And the models could be underestimating the range of outcomes because they do not fully factor in all the sources of feedback that could cause warming.

So when you read about limiting warming to 2 °C, remember this is far from guaranteed: it is just the most likely out of a range of possible outcomes. Worse still, it now seems certain that we will bust the carbon budget, and many scientists think plan B – sucking lots of CO 2 out of the atmosphere – will prove impossible. Maybe we’ll get lucky, but some very scary scenarios cannot be ruled out.

Leader: “We can’t afford a triumph of mediocrity at Paris climate talks”

(Images: Luke Sharrett/Bloomberg via Getty Images; Chris Sattlberger/Anzenberger/plainpicture; Monty Rakusen/Cultura/plainpicture)

This article appeared in print under the headline “Climate talk hope versus reality”