It is a vision of a future so apocalyptic that it is hard to even imagine.
But, if leading scientists writing in one of the most respected academic journals are right, planet Earth could be on course for global warming of more than seven degrees Celsius within a lifetime.
And that, according to one of the world’s most renowned climatologists, could be “game over” – particularly given the imminent presence of climate change denier Donald Trump in the White House.
Scientists have long tried to work out how the climate will react over the coming decades to the greenhouse gases humans are pumping into the atmosphere.
According to the current best estimate, by the Intergovernmental Panel on Climate Change (IPCC), if humans carry on with a “business as usual” approach using large amounts of fossil fuels, the Earth’s average temperature will rise by between 2.6 and 4.8 degrees above pre-industrial levels by 2100.
However new research by an international team of experts who looked into how the Earth’s climate has reacted over nearly 800,000 years warns this could be a major under-estimate.
Because, they believe, the climate is more sensitive to greenhouse gases when it is warmer.
In a paper in the journal Science Advances, they said the actual range could be between 4.78C to 7.36C by 2100, based on one set of calculations.
Some have dismissed the idea that the world would continue to burn fossil fuels despite obvious global warming, but emissions are still increasing despite a 1C rise in average thermometer readings since the 1880s.
And US President-elect Donald Trump has said he will rip up America’s commitments to the fight against climate change.
Professor Michael Mann, of Penn State University in the US, who led research that produced the famous “hockey stick” graph showing how humans were dramatically increasing the Earth’s temperature, told The Independent the new paper appeared "sound and the conclusions quite defensible".
“And it does indeed provide support for the notion that a Donald Trump presidency could be game over for the climate,” he wrote in an email.
“By ‘game over for the climate’, I mean game over for stabilizing warming below dangerous (ie greater than 2C) levels.
“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 UK said the new research was further evidence that urgent action was needed.
Dr Doug Parr, the environmental campaign group’s chief scientist, said: “The worrying thing is the suggestion climate sensitivity is higher [than thought] is not incompatible with higher temperatures we have been seeing this year.
“If there is science backing that up, that there’s a higher sensitivity of the climate to greenhouse gases, that puts at risk the prospect of keeping the globe at the Paris target of well below 2C.
“Anybody who understands the situation we find ourselves in would have already have realised we are in an emergency situation.”
Science news in pictures
Science news in pictures
1/20 'Tiny vampires' existed millions of years ago
Scientists have discovered that microscopic 'vampire' amoebae existed hundreds of millions of years ago, and they may have been some of the first predators on Earth. By examining ancient fossils with an electron microscope, paleobiologist Susannah Porter from UC Santa Barbara discovered tiny holes which may have been drilled by vampiric microbes. The tiny creatures are believed to be the ancestors of modern Vampyrellidae amoebae, and punctured holes in their prey before sucking out the contents of their cells
2/20 Kepler 62f
An Earth-like planet orbiting a star 1,200 light years away could have conditions suitable for life, say scientists. Kepler 62f is about 40 per cent larger than the Earth and may possess surface oceans. It is the outermost of five planets circling a star that is smaller and cooler than the sun discovered by the American space agency Nasa's Kepler space telescope in 2013
3/20 Vegetables grow well in soil from Mars
Scientists have taken a leaf out of the script of The Martian by showing how easy it would be to grow your own veg on the Red Planet. In the hit Ridley Scott film, a stranded astronaut played by Matt Damon uses his botanical skills to cultivate potatoes. Now his success has been emulated by researchers in the Netherlands who harvested tomatoes, peas, rye, rocket, radish and cress raised on simulated Martian soil supplied by Nasa
4/20 Ancient Roman 'leisure complex' unearthed in Jerusalem
An ancient Roman estate complete with its own wine press and bathhouse has been unearthed in Jerusalem. A series of buildings dating back at least 1,600 years were discovered underneath the city's famous Schneller Orphanage which operated on the site from 1860 until the end of the Second World War, when it was turned into an army base. The ruins were discovered by archaeologists from the Israel Antiquities Authority who were excavating the site ahead of building new flats for the city's Orthodox Jewish community
5/20 Scientists discover possible new species of deep-sea octopus nicknamed 'Casper'
Scientists believe they may have found a new species of octopus likened in appearance to Casper, the friendly cartoon ghost. Researchers with the US National Oceanic and Atmospheric Administration made the discovery by chance as they searched the seabed on an unrelated mission collecting geological samples. Teams were operating an unmanned submarine on the Pacific Ocean floor at depths of more than four kilometres (two-and-a-half miles) in the Hawaiian Islands when they spotted the unusual creature
6/20 Black hole captured eating a star then vomiting it back out
Astronomers have captured a black hole eating a star and then sicking a bit of it back up for the first time ever. The scientists tracked a star about as big as our sun as it was pulled from its normal path and into that of a supermassive black hole before being eaten up. They then saw a high-speed flare get thrust out, escaping from the rim of the black hole. Scientists have seen black holes killing and swallowing stars. And the jets have been seen before.But a new study shows the first time that they have captured the hot flare that comes out just afterwards. And the flare and then swallowed star have not been linked together before
7/20 'Male and female brains' aren't real
Brains cannot be categorised into female and male, according to the first study to look at sex differences in the whole brain. Specific parts of the brain do show sex differences, but individual brains rarely have all “male” traits or all “female” traits. Some characteristics are more common in women, while some are more common in men, and some are common in both men and women, according to the study
8/20 Dog-sized horned dinosaur fossil found shows east-west evolutionary divide in North America
A British scientist has uncovered the fossil of a dog-sized horned dinosaur that roamed eastern North America up to 100 million years ago. The fragment of jaw bone provides evidence of an east-west divide in the evolution of dinosaurs on the North American continent. During the Late Cretaceous period, 66 to 100 million years ago, the land mass was split into two continents by a shallow sea. This sea, the Western Interior Seaway, ran from the Gulf of Mexico to the Arctic Ocean. Dinosaurs living in the western continent, called Laramidia, were similar to those found in Asia
9/20 Asteroid to skim past Earth on Halloween 2015
A huge asteroid is set to skim by Earth on Halloween, just three weeks after it was first spotted. The rock is travelling through space at 78,000 miles per hour, and will fly past the Earth at a distance of only 300,000 miles – only slightly further away than our moon, and easily close enough for Nasa to class it a potentially hazardous object. The asteroid is bigger than a skyscraper
10/20 Life on Earth appeared hundreds of millions of years earlier than previously thought
Life may have come to earth 4.1 billion years ago, hundreds of millions of years earlier than we knew. The discovery, made using graphite that was trapped in ancient crystals, could mean that life began "almost instantaneously" after the Earth was formed. The researchers behind it have described the discovery as “a potentially transformational scientific advance”. Previously, life on Earth was understood to have begun when the inner solar system was hit by a massive bombardment from space, which also formed the moon's craters
11/20 Earth could be at risk of meteor impacts
Earth could be in danger as our galaxy throws out comets that could hurtle towards us and wipe us out, scientists have warned. Scientists have previously presumed that we are in a relatively safe period for meteor impacts, which are linked with the journey of our sun and its planets, including Earth, through the Milky Way. But some orbits might be more upset than we know, and there is evidence of recent activity, which could mean that we are passing through another meteor shower. Showers of meteors periodically pass through the area where the Earth is, as gravitational disturbances upset the Oort Cloud, which is a shell of icy objects on the edge of the solar system. They happen on a 26-million year cycle, scientists have said, which coincide with mass extinctions over the last 260-million years
12/20 Genetically-engineered, extra-muscular dogs
Chinese scientists have created genetically-engineered, extra-muscular dogs, after editing the genes of the animals for the first time. The scientists create beagles that have double the amount of muscle mass by deleting a certain gene, reports the MIT Technology Review. The mutant dogs have “more muscles and are expected to have stronger running ability, which is good for hunting, police (military) applications”, Liangxue Lai, one of the researchers on the project. Now the team hope to go on to create other modified dogs, including those that are engineered to have human diseases like muscular dystrophy or Parkinson’s. Since dogs’ anatomy is similar to those of humans’, intentionally creating dogs with certain human genetic traits could allow scientists to further understand how they occur
13/20 Nasa confirms Mars water discovery
Nasa has announced that it has found evidence of flowing water on Mars. Scientists have long speculated that Recurring Slope Lineae — or dark patches — on Mars were made up of briny water but the new findings prove that those patches are caused by liquid water, which it has established by finding hydrated salts.
14/20 Bees in the Rocky Mountains are evolving shorter tongues
With warmer summers, flowers in the Rockies have become shallower and more suited to shorter-tongued bees
15/20 The majority of the UK public believe in aliens
The titular alien character from 2011's 'Paul' - a poll has found the majority of the public in Britain, Germany and the US believe that intelligent life is out there in the universe
16/20 Researchers discover 'lost world' of arctic dinosaurs
Scientists say that the new dinosaur, known as Ugrunaaluk kuukpikensis, “challenges everything we thought about a dinosaur’s physiology”. Florida State University professor of biological science Greg Erickson said: “It creates this natural question. How did they survive up here?”
17/20 Scientists find exactly what human corpses smell like
New research has become the first to isolate the particular scent of human death, describing the various chemicals that are emitted by corpses in an attempt to help find them in the future. The researchers hope that the findings are the first step towards working on a synthetic smell that could train cadaver dogs to be able to more accurately find human bodies, or to eventually developing electronic devices that can look for the scent themselves.
18/20 The Syrian civil war has caused the first ever withdrawal from the 'doomsday bank'
Researchers in the Middle East have asked for seeds including those of wheat, barley and grasses, all of which are chosen because especially resistant to dry conditions. It is the first withdrawal from the bank, which was built in 2008. Those researchers would normally request the seeds from a bank in Aleppo. But that centre has been damaged by the war — while some of its functions continue, and its cold storage still works, it has been unable to provide the seeds that are needed by the rest of the Middle East, as it once did.
19/20 A team of filmmakers in the US have made the first ever scale model of the Solar System in a Nevada desert
Illustrations of the Earth and moon show the two to be quite close together, Mr Overstreet said. This is inaccurate, the reason being that these images are not to scale.
20/20 Academics claim a full bladder makes for a better liar
People lie more convincingly if they have a full bladder, according to research by academics at California State University. Iris Blandón-Gitlin's team asked 22 students to lie to a panel of interviewers. Half were given 700ml to drink before the interview and the other half, just 50ml. The students with the full bladders showed fewer signs that they were lying and their untrue answers were longer and more detailed, meaning interviewers were less able to detect that they were telling porkies. PM David Cameron has previously attested to giving speeches on a full bladder.
Dr Tobias Friedrich, one of the authors of the paper, said: “Our results imply that the Earth’s sensitivity to variations in atmospheric carbon dioxide increases as the climate warms.
“Currently, our planet is in a warm phase – an interglacial period – and the associated increased climate sensitivity needs to be taken into account for future projections of warming induced by human activities.
“The only way out is to reduce greenhouse gas emissions as soon as possible.”
Dr Andrey Ganopolski, who was involved in the research and on the IPCC’s latest report, admitted their work was controversial with some scientists disagreeing and others agreeing with their findings.
“In our field of science, you cannot be definite by 100 per cent. There are always uncertainties and we discuss this in the paper,” he said.
“If we have more and more results of this sort, then we have more reasons to be concerned.”
Dr Ganopolski, of the Potsdam Institute for Climate Impact Research in Germany, suggested their findings meant it would be harder to prevent the world entering dangerous global warming of 2C or above.
“Our results mean it is not impossible to stay within 2C but it probably – if we are right and climate sensitivity is higher than this – would require even strong cuts in carbon emissions,” he said.
“Whether it’s feasible politically … I believe it is feasible technically.
“It would be really good to stay below 1.5C or close to that, whether it’s feasible I’m probably a bit sceptical about that.”
Commenting on the paper, Professor Eric Wolff, of Cambridge University, said using data from the past was a “powerful way of understanding the climate”.
But he noted the authors had used different ways of estimating average global temperature, some of which had produced “a lower range of values”.
“The estimates of temperature in this paper are subject to large uncertainties, and therefore the range of estimates for 2100 is also very wide,” Professor Wolff said.
“Still, it's encouraging that it overlaps with model estimates and confirms that the emission reductions promised in Paris are essential to avoid unacceptable climate changes."
Mark Lynas laid out what would happen as the temperature rises in his award-winning book, Six Degrees: Our Future on a Hotter Planet.
He was shocked by the researchers’ results.
“It sounds on the apocalyptic side of bad and, in some ways, it is realistic because ‘business as usual’ just got more likely as Trump wants to rebuild the pipelines … the complete ‘fossilisation’ of the US,” he said.
“It was game over at six [degrees] to be honest. I don’t think there was much more to add, other than turning the planet into Venus.”
Nasa recently said Venus may once have been habitable before runaway global warming turned the planet into its current version of hell with temperatures of more than 460C, almost no water and an atmosphere of mainly carbon dioxide with clouds of sulphuric acid.