The official US delegation has been conspicuous in its absence at COP23. At its sole side event, US delegates promoted "clean" fossil fuels as a solution to reduce emissions.

First announced under the title "Action on Spurring Innovation and Deploying Advanced Technologies," the event was finally presented as "The Role of Cleaner and More Efficient Fossil Fuels and Nuclear Power in Climate Mitigation."

Governor of California Jerry Brown ridiculed his country's attempt at caring for the planet, while dozens of environmental activists who crashed the event chanted "Keep it in the ground" over the speech of Barry Worthington, executive director of the United States Energy Association.

They say that promoting cleaner fossil fuels is merely an excuse to keep profiting from fossil fuel industries, while slowing down the transition towards renewable energies.

"Events inside the climate talks which promote fossil fuels deserve to get disrupted," said Jogada Munic, Friends of the Earth (FoE) director for Europe. "The US has been deliberately provocative by organizing this. There is no space for fossil fuels in these talks or in a climate safe future."

But is there is a point in this discussion? Since we might be dependent on fossil fuels for much longer than hoped, wouldn't it be better to at least make them cleaner? And yet, is "clean fossil fuels" an oxymoron?

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"This panel is only controversial if we choose to bury our heads in the sand and ignore the realities of the global energy system," David Barks, special assistant for the White House, said in his opening speech.

Universal access to energy is required to help eradicate poverty and reach development goals – and this is only possible with fossil fuels, he argued.

"The idea that the world can meet ambitious mitigation goals, support development in poor countries the way we should, and ensure energy access by only deploying solar and wind is naive," Barks said.

But for California's Jerry Brown, this US move is simply ridiculous.

"I think the federal government is treading water. They've kind of become like Saturday Night Live, or a comedy program," Brown told DW.

"They're bringing in a coal company to teach the Europeans how to clean up the environment."

For environmental activists, the event is a clear response to US President Donald Trump's support for the fossil fuels industry.

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Cleaner fossil fuels?

Representatives from giant energy companies such as Peabody Energy Corporation – the largest private-sector coal company in the world – at the side event presented ways to realize the ideal of cleaner fossil fuels.

"There are technologies available today that can dramatically reduce emissions from coal and other fossil fuels," Holly Krutka, vice president of coal generation and emissions technologies with Peabody, said.

The main steps to make fossil fuels "greener" are to install high-efficiency, low-emissions systems in power plants, and upgrade the carbon capture and storage (CCS) process – capturing carbon dioxide (CO2) from large emitters such as coal power plants, and then storing it in a deposit to prevent it from entering the atmosphere.

However, Naomi Ages, the climate liability project lead at Greenpeace USA, believes "there is no such thing as cleaner fossil fuels." This is simply a strategy developed by the fossil fuel industry to slow the transition from coal, she said.

CCS and similar technological processes do not ensure the reduction of emissions at the required level – and are a waste of resources that would be better invested in scaling up renewable energies and replacing fossil fuels as fast as possible, Ages argued.

Read more: Can we live in a world without fossil fuels?

What future for fossil fuels?

A team of international researchers at Lappeenranta University of Technology in Finland released information at COP23 that a full decarbonization of the electricity system by 2050 is possible. 

By using renewables for the electricity system alone, emissions could drop 80 percent by 2030. Although many would lose their jobs in fossil fuel industries, renewable ernergies would create twice as many new jobs, according to their findings.

"The energy transition is no longer a question of technical feasibility or economic viability, rather of political will," said Christian Breyer, head of the research team.

Although industries like shipping, iron or cement still represent the greatest challenge in terms of moving to a 100-percent renewable energy system, Ages believes this could be overcome with further investment and more ambitious policies – again, boiling down to political will.

Christoph Weber, a professor of management science and energy economics at the University of Duisburg-Essen, in Germany, maintains that renewable energies will play a decisive role in the upcoming decades – but leaving fossil fuels behind will not be easy, nor fast.

"Fossil fuels will surely not help us solve our climate problems, but for now we should consider all available options - including CCS - if we want to keep global warming below 2 degrees [Celsius]," Weber said.

Just a hoax? Why mitigate?

For protesters who gathered inside and outside the event, there was clearly no future for fossil fuels, and they wanted to stand up to fossil fuel lobbyists, and prevent them from overshadowing the climate talks.

Some of them joked: Why would any US official delegate want to mitigate climate change if it were just a hoax?

"The Trump Administration should be held criminally accountable for what they are doing in the US and around the world," said Karen Orenstein, Friends of the Earth's US economic policy director, adding that President Trump had just "traipsed" through Asia "peddling climate pollution."

"Trump's actions demonstrate callous disregard - and possibly even genuine malevolence - toward people in poor countries, whose lives and livelihoods have been threatened, diminished, and in some cases destroyed by the devastating effects of climate change," Orenstein said.