A Clash Over Degrees: How Hot Should Nations Allow the Earth to Get?

SHARM EL SHEIKH, Egypt — At last year’s global climate talks in Glasgow, world leaders, scientists and chief executives rallied around a call to “keep 1.5 alive.”

The mantra was in reference to an aspirational goal that every government endorsed in the 2015 Paris climate agreement: try to stop global average temperatures from rising more than 1.5 degrees Celsius (2.7 degrees Fahrenheit) above preindustrial levels. Beyond that threshold, scientists say, the risk of climate catastrophes increases significantly.

Now, 1.5 is hanging on for dear life.

At the United Nations climate summit that is underway in this Red Sea town, countries are clashing over whether they should continue to aim for the 1.5-degree target.

The United States and the European Union both say that any final agreement at the summit, known as COP27, should underscore the importance of limiting warming to 1.5 degrees.

But a few nations, including China, have so far resisted efforts to reaffirm the 1.5-degree goal, according to negotiators from several industrialized countries. Failing to do so would be a major departure from last year’s climate pact and, to some, a tacit admission of defeat.

“When I arrived here, I got a really strong sense of backsliding,” said Mary Robinson, the former president of Ireland who leads a group of prominent former leaders called the Elders. Along with leaders of nearly 200 of the world’s largest businesses and civil society groups, Ms. Robinson signed a letter urging governments at the climate talks to stick with 1.5 degrees.

That temperature goal is “a limit of safe living,” Ms. Robinson said, adding, “Every increase of a tiny fraction of a degree is harmful, and we have to claw to prevent going above 1.5.”

For some nations, the dispute goes beyond digits. Leaders of low-lying island nations say vast swaths of their territories could wash away if global average temperatures were to surpass 1.5 degrees. “This is indeed a matter of survival for all vulnerable countries,” Kwaku Afriyie, Ghana’s environment minister, said.

At a gathering of the world’s 20 largest economies that is taking place in Bali, Indonesia, this week, leaders said they were resolved “to pursue efforts to limit the temperature increase to 1.5 degrees Celsius,” putting pressure on the diplomats at the climate talks in Egypt.

But with global carbon dioxide emissions reaching a record high this year, some negotiators fear that regardless of what is agreed to on paper, the 1.5-degree goal could soon be out of reach. The planet has already warmed an average of 1.1 degrees Celsius, compared with preindustrial levels, and under the current policies of national governments, the world is on pace to heat up 2.1 to 2.9 degrees Celsius this century, according to a recent U.N. report.

“The goal to limit global warming to 1.5 degrees is on life support,” Prime Minister Philip Davis of the Bahamas said in a speech to world leaders at the Egyptian conference. “This is a hard truth for many to admit, because even the best-case scenarios will mean almost unimaginable upheaval and tragedy.”

Russia’s invasion of Ukraine in February set off a global energy scramble that has complicated efforts to reduce the use of fossil fuels. As natural gas prices soared, countries in Europe and elsewhere switched to burning coal, an even dirtier fossil fuel, and began investing in new natural gas pipelines and terminals that could operate for decades to come. Russian fuel exports continued as well, despite Western sanctions, simply heading to different trading partners. In the United States, Republicans continue to call for expanded oil and gas production and exploration. Fossil fuel companies have even made a number of gas deals with nations at COP27.

All of that could make limiting global warming to 1.5 degrees virtually impossible, Al Gore, the former U.S. vice president, said in a speech on the opening day of the Egyptian summit.

“The world’s leading scientists and energy experts have told us that any new fossil fuel development is incompatible with 1.5 degrees as the limit to the temperature increase,” he said.

The Paris Agreement includes some ambiguity over what the world’s exact climate goals should be. The pact said that nations should commit to keeping global warming “well below” 2 degrees Celsius while “pursuing efforts” to limit warming to 1.5 degrees Celsius.

Half a degree doesn’t sound like much, but every fraction of a degree of additional warming could mean tens of millions more people worldwide exposed to life-threatening heat waves, water shortages and coastal flooding, scientists have found. A 1.5-degree world might still have coral reefs and Arctic sea ice, while a 2-degree world most likely would not.

The consequences are “massively different in terms of food security and the ability to grow crops in certain parts of the world, and in terms of the number of people that are exposed to extreme floodplain risk and extreme heat risk,” Raj Shah, the president of the Rockefeller Foundation, said.

Yet, at this point, keeping warming to 1.5 degrees would require drastic steps that would be costly, politically difficult and disruptive, and would require leaders of nearly all countries to act in concert. They would need to slash their collective fossil fuel emissions roughly in half by 2030, and then quit adding carbon dioxide to the atmosphere altogether by 2050, scientists have calculated. That would require a complete overhaul of all electricity and transportation systems at an unprecedented pace. And with every year of inaction, the task gets harder.

By comparison, to keep warming to 2 degrees, nations would have an extra decade to cut their emissions in half.

China, the world’s largest emitter, has several concerns about the 1.5 goal, said Li Shuo, a policy adviser for Greenpeace based in Beijing. It would put pressure on the Chinese government to adopt a more stringent domestic target for cutting greenhouse gases, something it wants to avoid, he said. And if the United States were to withdraw from the global fight against climate change, as it did under President Donald J. Trump, China would be left carrying the load alone.

“There is this skepticism about the United States’ ability to fulfill its promise,” Mr. Li said. “The U.S. could just walk away, citing congressional resistance, and on the other side, the Chinese will be held more accountable. ”

The Chinese delegation at COP27 did not respond to a request for comment.

India, the world’s third-largest emitter, has in the past been wary of focusing too much on the 1.5-degree target. To meet that goal, Indian officials have said, richer countries would have to cut their emissions much more rapidly than they are doing and provide more financial aid to poor nations, potentially on the order of trillions of dollars, to help them shift to clean energy. So far, wealthy governments have failed to do that.

The Indian delegation at COP27 declined to comment.

Some world leaders seem increasingly pessimistic that the 1.5 climate goal will be met even if nations do endorse the target. Words on paper, after all, don’t cut emissions.

Prime Minister Mia Mottley of Barbados is leading a campaign to reform the World Bank and the International Monetary Fund in order to unlock more money to help developing economies pivot from fossil fuels. She said that it wasn’t enough to chant “1.5 to Stay Alive” in hopes that it would bring about change.

“I take no pride in being associated with having to repeat it over and over and over,” she said.

Instead, she said, after a year of record storms, floods, fires and droughts, nations must do the hard work of cutting carbon dioxide, methane and other gases that are trapping heat in the atmosphere.

For the determined optimists, however, there are glimmers of hope.

This year, Mr. Biden muscled through the Inflation Reduction Act, America’s first major climate legislation, which will pour $370 billion into low-carbon technologies like wind turbines, solar panels, nuclear power plants, hydrogen fuels, electric vehicles and electric heat pumps. It is projected to help the country cut its emissions by 40 percent below 2005 levels by 2030.

In a speech at the climate summit, Mr. Biden called on other nations to follow his lead and come up with plans to reduce their planet warming emissions quickly.

“If we’re going to win this fight, every major emitter nation needs align with the 1.5 degrees,” Mr. Biden said. “We can no longer plead ignorance to the consequences of our actions or continue to repeat our mistakes.”

Another recent development that has cheered those who believe 1.5 is still possible was the election of Luiz Inácio Lula da Silva, a committed environmentalist, as the president of Brazil. Mr. Lula, who is scheduled to speak at the climate summit on Wednesday, has pledged to protect the Amazon rainforest. Mr. Lula ousted Jair Bolsonaro, who cut environmental programs and oversaw a sharp rise in deforestation.

“There is an opportunity to protect the Amazon rainforest, which is critical for protecting our global climate,” said Leila Salazar-Lopez, the executive director of Amazon Watch, a nonprofit organization. “If the Brazilian election would have gone the other way, then I think we would definitely be beyond a tipping point and we would not have a chance for 1.5.”

The International Energy Agency has also predicted that the energy crisis incited by Russia’s invasion of Ukraine will spur more nations to invest in lower-emissions technologies this decade in order to improve their energy security. Global investment in clean energy is now expected to rise from $1.3 trillion this year to more than $2 trillion annually by 2030, though that is still only half of what is needed to hold warming to 1.5 degrees.

“The science shows us that we can actually turn things around if we stop fossil fuel expansion and carbon emissions,” Osprey Orielle Lake, the executive director of the Women’s Earth and Climate Action Network, said. “It’s like an 11th-hour save, but we can’t give up.”