The United Nation’s former global warming czar has published a paper claiming humanity only has three years left to avert dangerous global warming and meet the goals of the Paris climate accord.

To do that, Christiana Figueres says governments and businesses need to pony up $1.3 trillion a year by 2020 earmarked for “climate action” to decarbonize the global economy. That’s on top of boosting green energy and phasing out fossil fuels, mostly coal.

“[S]hould emissions continue to rise beyond 2020, or even remain level, the temperature goals set in Paris become almost unattainable,” Figueres, the former head of the United Nations Framework Convention on Climate Change, wrote in an article published in Nature. “The UN Sustainable Development Goals that were agreed in 2015 would also be at grave risk.”

“These goals may be idealistic at best, unrealistic at worst. However, we are in the age of exponential transformation and think that such a focus will unleash ingenuity,” Figueres wrote in her article, which was co-authored by a few environmentalists and scientists.

The Paris accord aims to “significantly reduce the risks and impacts of climate change” by keeping global warming “well below” two degrees Celsius by 2100. Beyond that, many activist scientists say global warming poses a danger to humanity.

World leaders are set to meet at the G20 summit in July, and Figueres wants them to “highlight the importance of the 2020 climate turning point for greenhouse-gas emissions” by imposing more policies to reduce greenhouse gas emissions and putting up more money for climate programs.

Figueres isn’t the first to propose a costly plan to limit future global warming. A group associated with former Vice President Al Gore issued a report in April calling for $15 trillion to be spent on green energy and other programs to limit global warming.

The Gore-affiliated Energy Transitions Commission’s (ETC) called for “investment in renewables and other low-carbon technologies some $6 trillion higher ($300 billion per year); while the largest required increases – of almost $9 trillion ($450 billion per year) – will be in more efficient energy saving equipment and buildings.”

A recent Bloomberg New Energy Finance report estimated $12.7 trillion was needed to keep projected global warming below 2 degrees Celsius by the end of the century.

The report estimated $7.4 trillion will be invested in new green energy capacity by 2040, adding a “further $5.3 trillion investment in 3.9 [terawatts] of zero-carbon capacity would be consistent with keeping the planet on a 2-degrees-C trajectory.”

Figueres calls for about $1.3 trillion a year to fight global warming by 2020. So the actual cost of her plan is likely on par or higher than those suggested outlined by the Gore group and Bloomberg.

“[P]lans to fully decarbonize buildings and infrastructures by 2050, with funding of $300 billion annually,” she wrote, adding the “financial sector has rethought how it deploys capital and is mobilizing at least $1 trillion a year for climate action.”

That includes issuing “green bonds” to finance climate programs.

The world would need to get 30 percent of its electricity from green sources, electric vehicles would need to be 15 percent of the global vehicle fleet and reduce deforestation, wrote Figueres and company.

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This article originally appeared in The Daily Caller