Under Trump the world's wealthiest nation will not do what must be done to reign in emissions. He has cast a shadow over the COP22 climate talks. Trump's disdain for climate action and support for fossil fuels virtually guarantees that we will blow past tipping points from which we may not be able to recover. Rising seas alone are already displacing people and left unchecked they will wreak unparalleled havoc on coastlines around the world.
As explained by the United Nations:
"With the climate changing faster than at any point in human history, aggressive action to reduce greenhouse gases is urgent. The energy sector, accounting for two-thirds of global emissions, must be a top priority for action if we are to keep temperature rise well below 2°C. Transitioning to renewable energy, underpinned by energy efficiency measures, is the single most effective way to rapidly reduce emissions."
Far from being alarmists, scientists are very cautious. Some of the most recent reports suggest that the situation is far worse than we thought. In an Independent article, Ian Johnston cites a recent study which claims that by 2100 warming may be as much as five degrees Celsius more than the most recent predictions from the Intergovernmental Panel on Climate Change (IPCC). As stated in the headline: "Climate change may be escalating so fast it could be 'game over', scientists warn."
The new climate research, (Friedrich, et al. (2016)) suggests the Earth's climate may be more sensitive to greenhouse gases than previously thought. A seven degree Celsius temperature increase could trigger a process similar to what happened on Venus.
There was a time when Venus had habitable temperatures that could have supported life. However, greenhouse gases warmed the planet into a 460C version of hell. Johnston calls it, "a vision of a future so apocalyptic that it is hard to even imagine."
The international team of experts surveyed almost 800,000 years of the Earth's climate history including a 1degree Celsius rise in average temperature since the 1880s.
Professor Michael Mann, of Penn State University, said:
"And it does indeed provide support for the notion that a Donald Trump presidency could be game over for the climate...If Trump makes good on his promises and the US pulls out of the Paris [climate] treaty, it is difficult to see a path forward to keeping warming below those levels."Greenpeace scientist, Dr Doug Parr put it even more bluntly when he said:
“Anybody who understands the situation we find ourselves in would have already have realised we are in an emergency situation.”