COP27: pledge to keep global warming to 1.5C explained - is it possible to keep temperatures down?

The world is “on the highway to climate hell with our foot still on the accelerator”, UN secretary-general Antonio Guterres has warned at the start of COP27.

Addressing world leaders at the start of the climate summit in Sharm El-Sheikh, Egypt, he said “we are in the fight of our lives – and we are losing”, with greenhouse gases still growing and temperatures still rising.

It comes ahead of Rishi Sunak’s speech to the conference, which the Prime Minister is attending following what opponents called a “screeching U-turn”, having planned to stay home to work on domestic financial issues.

Mr Sunak will use his speech to the conference to call for a “global mission for clean growth”. He will say it is essential countries stick to commitments made at the COP26 summit hosted by the UK in Glasgow, if it is to limit warming to 1.5C above pre-industrial levels and avoid the worst impacts of climate change.

At the same time, he will argue that the transition away from fossil fuels has the potential to drive growth and deliver jobs in the new green industries of the future, while cutting off funding for Russia’s war in Ukraine. But what is the 1.5C pledge, and is it possible to keep temperatures down?

What is the 1.5C pledge?

The 1.5C target was one of the aims of the Paris Agreement in 2015. Its aim was to reduce global emissions and warming. The document stated that countries should strive to keep the rise in global warming temperatures to an ideal target of 1.5C with a target of keeping them “well below” 2C.

Scientists say that keeping global temperatures from rising more than 1.5C by 2100 will help to reduce the risk of these devastating effects to places such as Australia, Africa and the Middle East. At COP26 nearly 200 countries agreed the Glasgow Climate Pact to keep the 1.5C goal alive.

Speaking last year the president of COP26 Alok Sharma said:“We can now say with credibility that we have kept 1.5 degrees alive. But, its pulse is weak and it will only survive if we keep our promises and translate commitments into rapid action.”

What progress has been made?

Countries agreed under the Paris climate treaty in 2015 to curb warming to “well below” 2C and pursue efforts to limit it to 1.5C above pre-industrial levels to avoid the worst impacts of climate change, but a lack of action has led to warnings that the 1.5C goal is slipping away.

Latest assessments from the UN show climate action plans fall far short of what is needed to limit dangerous climate change, bringing down emissions by only 5-10% by 2030, compared to the 45% cut needed to keep temperatures rises to the 1.5C threshold countries have signed up to.

Greenhouse gases continue to rise, and there is no credible pathway in place to meeting the 1.5C goal, the UN Environmental Programme (UNEP) warns.

The global average temperature in 2022 is estimated to be about 1.15C above levels seen in the 1850-1900 period, the WMO said.

That puts 2022 on track to be the fifth or sixth warmest year on record, in the face of a rare triple-dip La Nina weather phenomenon in the Pacific which has naturally cooled global temperatures for the past two years. But the World Meteorological Organisation warned that did not mean there was a reversal in the warming trend.

The eight years since 2015 are likely to be the eight warmest years on record, and the impacts of global warming are becoming more pronounced.

WMO secretary-general Petteri Taalas said: “The greater the warming, the worse the impacts. We have such high levels of carbon dioxide in the atmosphere now that the lower 1.5C of the Paris Agreement is barely within reach.”

He warned it was “already too late for many glaciers” and melting would continue for hundreds if not thousands of years, with major implications for water security.

Is it possible to keep temperatures down?

A climate scientist says the world has a “really, really small window” to keep to the target of limiting global warming to 1.5C.

Professor Hannah Cloke told BBC Radio 4’s Today Programme: “The time we have to change the course is getting shorter and shorter and shorter and there just feels like a lot of talking and no action, and as a climate scientist it is just awful, it’s really, really frustrating.

“People say to scientists like me coming on your programme: stick to the facts don’t frighten people, don’t give your opinion – but us scientists, we’ve been doing that for 30 years now with increasing alarm and we just don’t have this widespread action that’s needed.”

On if the 1.5C target for the increase in global temperatures is still alive or “way off”, she said: “We are so close to being way off, so we have this really, really small window to keep to that. I think most climate scientists are incredibly worried that we are not going to make it.

“To be honest it is a little bit arbitrary because every tenth of a degree that we can stop means less terrible things happening in the future, so it’s a good target to have a target because it means we can take action and put our money into technology, into changing our way of living, into cutting emissions.

“What we really should focus on, the more action we take right now, the less worse things will be in the future and that means less bad floods, less bad droughts, less bad storms at the coast.”