Underneath the chorus of new climate commitments and calls for collaboration that have echoed through the first week of the COP26 conference in Glasgow, a hum of anxiety can be heard.

The tens of thousands of diplomats, scientists, technocrats and activists at the summit know the cruel math of climate change by heart. They recognize that the Earth has already warmed more than 1.1 degrees Celsius (2 degrees Fahrenheit) since the start of the Industrial Revolution. They’re aware that if temperatures rise just a few fractions of a degree further, the planet could see species vanish, sea levels surge and natural disasters intensify to unheard of extremes.

So they knew what it meant when a new Global Carbon Budget was released in the early hours of Thursday morning, showing global greenhouse gas emissions have almost completely rebounded after their pandemic slump. The world has just 11 years of burning carbon at the current rate if humanity hopes to have a chance of avoiding catastrophic climate change.

The path to limiting global warming to 1.5 degrees Celsius (2.7 degrees Fahrenheit) is getting harder and harder to see.

Given that crystallizing reality, U.N. officials warned Thursday in their annual Adaptation Gap report, the world will have to devote far more resources to helping vulnerable communities adapt to the looming climate upheaval.

Developing nations need five to 10 times more funding to cope with escalating damage, the report found. By the middle of the century, these countries’ adaptation needs could reach $500 billion per year.

Yet wealthy nations have fallen behind on their pledge to provide low-income counterparts with $100 billion per year to cope with climate impacts and transition to clean energy. And the vast majority of funds they’ve given have focused on cutting emissions, rather than helping people harmed by the crises that are already underway.

As negotiators in Glasgow grapple with how the world should curb greenhouse gases, who should be responsible and when the deadlines should be, the Global Carbon Budget is a “reality check” said co-author Corinne Le Quéré, a climate scientist at the University of East Anglia.

“You have to look the risks in the eye,” she said. “And the risk is really high that we don’t succeed.”

“You have to prepare for a lot more,” she continued. “You need to mitigate for 1.5 degrees and prepare for 3 degrees.”

The promises of the past week in Glasgow do seem to represent progress. An analysis released Thursday by the International Energy Agency estimated that all the climate pledges announced to date could limit warming to 1.8 degrees Celsius (3.2 degrees Fahrenheit) above preindustrial levels — but only if all those pledges are met “in full and on time.”

That is a dramatic improvement from the path to 2.7 degrees Celsius (4.9 degrees Fahrenheit) of warming that U.N. scientists projected just two weeks ago.

When you look at the analysis of how many degrees Celsius of global average temperature rise we’ve shaved off from the predictions between Paris and now, it’s several degrees, and that’s impressive,” Jacob Werksman, the lead European Union climate negotiator, said in an interview Thursday. “It’s just not enough.”

But, like many at the conference, he remained skeptical of the IEA report’s findings given humanity’s track record. None of the net-zero pledges nations made this week have actually been put into action.

“Without policies to implement them,” he said, “the atmosphere will not see the effect.”

Since 2015, the Global Carbon Project has tracked the dwindling amount of carbon dioxide humanity can afford to emit if it hopes to meet the most ambitious aims of the Paris climate agreement. Back then the quota was 903 gigatons — about 20 years worth of emissions — to avoid surpassing 1.5 degrees Celsius.

But despite the global call to action and the unprecedented economic shutdowns of the covid-19 pandemic, fossil fuel pollution has continued to rise. In just six years, people burned through half their remaining carbon allotment.

Emissions from burning coal and natural gas reached even higher levels in 2021 than before the pandemic, scientists found. The leading cause of the surge was economic growth in China — the world’s top emitter, which gets the bulk of its energy from coal. India, another coal-dependent country, likewise saw a spike in emissions as its economy restarted.

Planet-warming pollution also grew 7.6 percent in the United States and the European Union, the second- and third-biggest producers of greenhouse gases, respectively. By the end of the year, total emissions from these regions are expected to be just a few percentage points below their pre-pandemic levels.

“We are still waiting to see the implementation of climate policies across the world that would actually bend the curve,” said University of Exeter climate scientist Pierre Friedlingstein, the lead author of the carbon budget.

To have even a 50 percent chance of keeping emissions within the parameters of the 1.5 degree Celsius threshold, the world must immediately start cutting annual carbon dioxide emissions by about 1.4 gigatons, the equivalent of planting about 21 billion trees each year.

Missing this goal would not mean humanity is doomed, Friedlingstein said. People can and probably will have to learn to live on an even warmer planet — but governments must invest in the tools to help them cope.

“The window we had in the last few decades of acting more on mitigation so we have to deal with less climate disasters, so we would spend less on adaptation — that window of opportunity is lost,” said Harjeet Singh, a New Delhi-based senior adviser for Climate Action Network International.

Now, millions are already suffering amid prolonged droughts, catastrophic wildfires, chronic flooding and worsening storms brought about by rising temperatures.

“We cannot leave people unprepared for disasters,” Singh added. “We cannot leave people on their own who are already facing a climate emergency.”

Global annual spending on adaptation is about $46 billion, the United Nations says — about 15 percent of what is spent on “mitigation,” or curbing emissions.

COP26 President Alok Sharma acknowledged at a news conference Thursday that “for too long, adaptation has been the poor cousin of mitigation.”

Henry Neufeldt, chief editor of the Adaptation Gap report, said it can be difficult to solicit funds for adaptation projects because they don’t offer obvious ways to gain a return on investment.

And many of the countries hit hardest by climate change are also buried in debt, especially after the pandemic decimated developing economies.

“We need more solidarity,” United Nations Environment Program Executive Director Inger Andersen said Thursday. She called on the world to help relieve the financial burden on low-income countries, allowing them the resources needed to adapt to looming disasters.

Representatives of vulnerable countries, along with civil society groups and the United Nations secretary general himself, have called for the world’s wealthy to not only fulfill their financial pledges, but make sure half of those funds go toward helping people adjust to a warmer and more dangerous world.

Sonam Wangdi, who chairs a negotiating group at the summit known as the Least Developed Countries, said the 46 nations in that bloc represent more than 1 billion people but are responsible for less than 1 percent of global emissions.

“There is not much we can do. So we have a climate crisis at hand,” he said.

That is why his country and others are so determined to make sure that the developed world makes good on its promises.

“For us, our lives depend on decisions that are made here in Glasgow,” he said. “Our lives will depend on the commitments that are made here.”

Kasha Patel and Brady Dennis in Washington, and Michael Birnbaum in Glasgow, Scotland, contributed to this report.