By Mariette Le Roux
US President Barack Obama has warned global warming poses imminent security and economic risks, as negotiators embarked on an 11-day race to seal a UN pact aimed at taming climate change.
Speaking after attending a historic climate summit with about 150 other leaders, Obama voiced confidence mankind would make the tough decisions needed to halt rising temperatures.
But the president of the world's second-largest carbon emitter also issued a grim warning for the near future if the temperature curve went unchecked.
"Before long we are going to have to devote more and more of our economic and military resources, not to growing opportunity for our people, but to adapting to the various consequences of a changing planet," Obama said on Tuesday (local time).
"This is an economic and security imperative that we have to tackle now."
The UN talks aim to seal a deal that would slash carbon emissions, which come mainly from burning fossil fuels, from 2020 and deliver hundreds of billions of dollars in aid for climate-vulnerable countries.
It is the latest chapter in a 25-year-old diplomatic saga marked by spats over burden-sharing and hobbled by a negotiation system of huge complexity.
Behind their vows of support, many leaders have often preferred the short-term benefits of burning cheap and dependable fossil fuels to power prosperity, ignoring the consequences of carbon pollution.
Obama said he believed the global political landscape was shifting, boding well for Paris and beyond.
"Climate change is a massive problem, it is a generational problem. And yet despite all that, the main message I have got is, I actually think we are going to solve this thing," he said.
Bureaucrats from 195 nations have until just Saturday to distil a 54-page text into a global warming blueprint, before handing it over to environment and foreign ministers for a final push to seal a deal by December 11.
Many issues could derail the Paris talks, including poor nations' demands for billions of dollars in support from rich countries to help them reduce their emissions and adapt to the consequences of global warming.
Dozens of poor nations are calling for a target of 1.5degC warming above pre-Industrial Revolution levels, while bigger polluters such as the US and China are backing a 2degC warming limit.
Disagreement over how to share responsibility for curbing emissions is one of the thorniest issues, and developing nations have accused richer countries of hypocrisy for demanding they cut their use of fossil fuels after carbon-burning their way to prosperity.
Adding to the debate, British charity Oxfam on Wednesday released a report saying the richest 10 percent of people produce half of earth's climate-harming fossil-fuel emissions, while the poorest half contribute a mere 10 percent.
"Rich, high emitters should be held accountable for their emissions, no matter where they live," Oxfam climate policy head Tim Gore said in a statement.
The legal status of the accord, which must get unanimous backing, is another bone of contention.
On Tuesday, Republicans in the US House of Representatives blocked Obama's regulations on reducing greenhouse gas emissions, a move he will likely veto, but which highlights the intense domestic opposition he faces in committing the US to any international framework.
Heaping on pressure, Climate Action Tracker on Tuesday warned if planned new coal-fired plants come online, that would wreck the summit's hopes of curbing warming by 2degC.
"There is a solution to this issue of too many coal plants on the books: cancel them," said Pieter Van Breevoort of Ecofys, an energy research organisation, which is part of the Climate Action Tracker group.