GLASGOW—As COP26 delegates went into overtime Friday night, shaping the language of their final climate communiques into something all 197 countries could agree on, scientists from around the world issued their latest, and perhaps starkest warning. 

“We, climate scientists, stress that immediate, strong, rapid, sustained and large-scale actions are necessary to hold global warming to well below 2°C and pursue efforts to limit it to 1.5°C,” they wrote in a Nov. 11 letter to the conference.

More than 200 scientists from every continent signed the letter to remind delegates at the conference that there’s no negotiating with science, said Sonia Seniveratne, a climate researcher with ETH Zürich and lead author of the latest climate science report from the Intergovernmental Panel on Climate Change.

“This is one of the last opportunities to limit warming to 1.5 degrees Celsius,” she said. Since the countries of the world agreed to that target in the 2015 Paris climate agreement, she said, “no progress has really been made. When you look at the declarations from the COPs since then, they are inconsistent with the science.”

“The core issue is carbon dioxide and fossil fuels, especially in terms of reducing emissions, and the numbers just don’t add up,” she said. If the climate conference—which was scheduled to conclude Friday but announced that negotiations would continue into the weekend—is to be successful, she said, the negotiators have to grapple in a meaningful way with the still-increasing global reliance on coal, oil and gas and the climate warming emissions they cause.

But, with the United States back in the negotiations, she added, the geopolitics are more favorable than ever to making more progress at COP26.

“In previous climate summits, some of the very stark scientific evidence was not taken up and acknowledged by the COP,” said Joeri Rogelj, who also signed the letter and is director of research at the Grantham Institute at Imperial College, London. “In the decisions being taken here by the governments, we’re hoping our emphasis helps spur scientifically robust action.”

The draft documents on the table right now give some hope that the tide might be turning in that direction, he said. For the first time, fossil fuels were specifically mentioned in the draft agreement of the Glasgow conference, which was released Wednesday.

“If you look at the draft text, I think it’s really positive that there is explicit acknowledgment of the science showing the urgency to act,” Rogelj said. “This is an absolutely crucial first step. Since global climate governance by design is intended to be science based, that would seem normal, but in past COPs and past years, that has not always been the case.” 

Whether the passages that mention fossil fuels or certain scientific realities of climate change remain in the final document that will be signed at the close of COP26 is among the sticking points that have dragged out the negotiations, making the timing of the scientists’ communiqué all the more apt.

“The letter reflects the assessments of scientists in the field,” he said. “As humans, as concerned persons, we have a lot of knowledge of what is going on, and we are deeply concerned.”

Unmet Expectations

Not all scientists are convinced that the Glasgow meeting marks a turning point.  

“It definitely sounds like the same old, same old,” said ice researcher Jason Box, with the Geological Survey of Denmark and Greenland. After spending a week at the conference presenting dire new research from the Arctic, Box said he hoped for a lot more in the way of a global response to the deepening climate crisis.

“The lack of a science-based response is alarming,” he said. “The science content of the sessions I was in was very clear that we’re in deep, so there does appear to be a disconnect between the science and the policy response.”

Denmark, where Box lives, has 23 new laws coming into effect in the next two years that will reduce the country’s emissions 70 percent by 2023, he said. He had hoped other nations at COP would announce similar actions.

“We’re on real catastrophic trajectories,” he said. “We’re entering the era of abrupt sea level rise, but that will be biting us a lot later than the droughts and crop failures. There are already a lot of losses and damages and we’re on deck for those to increase. Crossing planetary boundaries is imminent. Where’s the leadership?”

During a short break from one of the last general negotiating sessions, Piers Forster, director of the climate research Priestley Centre in Leeds, United Kingdom, said Saudi Arabia appeared to be the last country arguing to weaken language in the COP agreement on the need for quick and deep cuts in greenhouse gas emissions.

“A lot of countries are saying we need really strong texts, and to come back with even stronger targets next year to keep the goal of limiting warming to 1.5 degrees Celsius,” he said. “If you looked at what countries submitted before COP26, at what they were putting forward, it was always about long-term targets. They were not saying much about the next 10 years.”

Forster said the recent letter from scientists emphasized that, after decades of inaction by nations to reduce their production of greenhouse gases, the world’s carbon budget—what additional emissions humans can put into the atmosphere before triggering the worst impacts of climate change—could be exhausted sometime between 2027 and 2033. 

So far, there are only promises of reductions, with no hard and fast signs that global emissions will decrease, he said. Right now, the planet is on a path to heat by about 2.5 degrees Celsius by 2100, after decades of unfulfilled pledges to reduce climate-warming gases. And even if nations achieve the Paris agreement goal of limiting global warming to 1.5 degrees Celsius, the changing climate will still bring devastation and suffering to wide parts of the world, Forster said. That adds urgency to COP negotiations about how to pay for the damage global warming is already causing and finance the adaptations required to endure it , especially in developing countries.

“There is no safe level of climate change,” he said. “Things are not going to be OK at 1.5 degrees.”

New, Devastating Research for COP to Consider 

Forster’s point was reinforced by a slew of climate studies that appeared just before and during COP26. For example, on Nov. 10, the World Meteorological Organization released a climate report on the Southwest Pacific at the conference showing that the ocean in that region is heating more than three times faster than the global average, leading to ocean heat waves that are devastating coral reefs and fisheries.

The report highlighted the risks that warming will drive, such as changes in ocean circulation, acidification and oxygenation, as well as rising sea levels, said WMO Secretary General Petteri Taalas. 

“The Small Island Developing States are increasingly vulnerable to these changes, as their incomes are highly linked to fisheries, aquaculture and tourism,” he said, describing the changes as an existential threat to many countries in the region.

Those impacts raise the stakes for the COP26 negotiations about how rich countries, whose emissions caused most of the warming, should compensate poorer countries that are suffering most of the damages. COP26 observers said the United States and the European Union are blocking an effort by the G77 group of developing countries to explicitly address that issue, which is one of the main reasons the talks are going into overtime. 

Climate research from the Arctic is just as worrisome, according to researchers who released a new report just ahead of COP 26.

“The polar regions are no longer an early warning signal for climate change,” said Jane Francis, Director of the British Antarctic Survey. “Instead, they are now a driver of climate change and this reality needs to be better understood.”

The rapid warming of the Arctic and Antarctica have intensifying climate feedback effects, including increasing releases of carbon dioxide and methane from thawing permafrost, making it “critical that international mitigation policies address this catastrophic regional and global hazard,” said Rachael Treharne, with the Woodwell Climate Research Center in Massachusetts.

In person, as well as in Thursday’s letter, scientists tried once again to warn COP26 participants, and the world, that some of these impacts are irreversible. 

“Negotiators may think they know about melting ice caps,” said Robert DeConto, with the Scientific Committee for Antarctic Research. “But what they don’t realize is that the impacts are essentially permanent on human timescales, and catastrophic for humanity.”