With a critical global climate summit just over a month away, worried government and business leaders are racing this week to try to drum up support for deeper carbon emission cuts and more adaptation aid ahead of COP26.

Speaking before the United Nations General Assembly, President Joe Biden pledged Sept. 21 to work with Congress to double U.S. public financing to $11.4 billion to help developing nations reduce emissions and prepare for more extreme weather events.

"This will make the United States a leader in public climate finance," Biden said. "With our added support, together with increased private capital and ... from other donors, we'll be able to meet the goal of mobilizing $100 billion to support climate action in developing nations."

The U.N. General Assembly and Climate Week NYC, held in New York City this week, have both turned into platforms advocating urgent action after scientists this year warned that nations are falling farther behind targets set by the Paris Agreement on climate change.

Most recently, the U.N. reported in a Sept. 17 summary of national emission reduction plans that the world is on a "catastrophic path." Absent immediate reductions in greenhouse gas emissions, the world will warm by 2.7 degrees C by 2100 from pre-industrial times. Such an increase is far above what scientists say ecosystems and economies can tolerate, the report said.

COP26 'our last best chance'

So far, some 30% of nations have yet to set a 2050 net-zero emission target as required under the Paris accord. That includes China, the world's largest emitter, and India, which ranks third after the U.S.

"There are large G20 emitters that have not yet come forward with ambitious commitments to do so," Alok Sharma, COP26's president, told a Climate Week panel Sept. 21. "I don't exaggerate when I say that COP26 is our last best chance to get this right."

A recent analysis by the Climate Action Tracker said that even countries that promised to zero out emissions are behind the game. Only one small African nation, The Gambia, is on track to meet the Paris Agreement's goal to limit global warming to 1.5˚C, the report concluded. The Climate Action Tracker consortium assesses the "nationally determined contributions," or NDCs, that countries submit to the U.N.

Last week's U.N. update on the NDCs, which 191 countries have now submitted, estimated that global emissions will increase 16% by 2030 over 2010 levels. That rise defies repeated calls for deep and sustained reductions from the world's climate experts.

But Climate Action Tracker spokeswoman Cindy Baxter said in an email that the global emissions increase could actually be more in the 2-3% range because both China and India "are likely to well-overachieve their NDCs."

Biden's top climate diplomat, John Kerry, told the Climate Week NYC panel that his team is "doing everything possible to raise ambition on a global basis." The U.S. is assisting India as it seeks to install 175 GW of renewable energy capacity by 2022, and engaging with Russia, South Africa, Indonesia and other large emitters to help where possible, he said.

"When we go to Glasgow the world has an opportunity ... to take action globally to prevent catastrophe," the climate envoy said. "We will be in a position all of us to raise ambition sufficiently to ... keep the hope of limiting the temperature rise to 1.5 degrees C, at least keep that hope alive in the next decade."