Human civilisation as we know it may have already entered its last decades, a worrying new report examining the likely future of our planet’s habitability warns.

The increasingly disastrous impacts of the climate crisis, coupled with inaction to tackle it are sending our planet down a bleak path towards an increasingly chaotic world which could overwhelm societies around the globe, the report’s authors contend.

The paper, produced by the Melbourne-based think tank the Breakthrough National Centre for Climate Restoration, is presented by the former chief of the Australian Defence Forces and retired Royal Australian Navy Admiral Chris Barrie.

In his introduction he says the report’s authors “have laid bare the unvarnished truth about the desperate situation humans, and our planet, are in, painting a disturbing picture of the real possibility that human life on earth may be on the way to extinction, in the most horrible way.”

The paper argues that “climate change now represents a near to mid-term existential threat to human civilisation,” and calls for a recalibration in how governments respond to estimated climate scenarios so they take worst case projections more seriously.

Coral reefs: Trying to combat climate change damage Show all 25 1 /25 Coral reefs: Trying to combat climate change damage Coral reefs: Trying to combat climate change damage Masked Butterflyfish (Chaetodon semilarvatus) swimming over a bommie reef in the Egyptian Red Sea marine reserve of Ras Mohamed, off the southern tip of the Sinai peninsula AFP/Getty Coral reefs: Trying to combat climate change damage Rising sea temperatures cause corals to bleach (go white) and die Getty/iStock Coral reefs: Trying to combat climate change damage A giant clam is seen nestled among coral reefs at the Obhor coast, 30 kms north of the Red Sea city of Jeddah AFP/Gett Coral reefs: Trying to combat climate change damage Coral reef in seychelles that has degraded After the reef has died they break up and become rubble. On this reef there is some regrowth of young corals so there is hope for recovery Getty Coral reefs: Trying to combat climate change damage Coral gardening A rabbitfish in a net H Goehlich Coral reefs: Trying to combat climate change damage A school of fish and a sea can in a healthy coral reef off the coast of Isla Mujeres, Mexico Getty/Lumix Coral reefs: Trying to combat climate change damage Sky views of great barrier reef in Australia Getty/iStock Coral reefs: Trying to combat climate change damage A fish swims among coral reefs at the Obhor coast AFP/Getty Coral reefs: Trying to combat climate change damage Researchers from the Interuniversity Institute for Marine Sciences in the southern Israeli resort city Eilat monitor coral growth while scuba diving in the Red Sea AFP/Getty Coral reefs: Trying to combat climate change damage Coral gardening A rope nursery Nature Seychelles Coral reefs: Trying to combat climate change damage Fish swimming off the coast of Egypt's Red Sea resort of Hurghada. The rebounding tourism sector is worrisome for the fragile marine ecosystem AFP/Getty Coral reefs: Trying to combat climate change damage Coral gardening A parrotfish on the reef C Reveret Coral reefs: Trying to combat climate change damage Gorgonian sea fan on a a coral reef in the Egyptian Red Sea marine reserve of Ras Mohamed AFP/Getty Coral reefs: Trying to combat climate change damage A diver swims during a Great Barrier Reef experience on Lady Elliot Island, Australia Getty/Tourism Queensland Coral reefs: Trying to combat climate change damage Jessica Bellsworthy, a PhD student conducting research on the coral reefs of the Gulf of Eilat, holds a coral in an aquarium at the Interuniversity Institute for Marine Sciences in Eilat AFP/Getty Coral reefs: Trying to combat climate change damage Coral reefs in the water off the Obhor coast, 30 kms north of the Red Sea city of Jeddah in 2008 AFP/Getty Coral reefs: Trying to combat climate change damage A diver photographs golden anthias (Pseudanthias aurulentus) on a coral reef in the Egyptian Red Sea marine reserve of Ras Mohamed AFP/Getty Coral reefs: Trying to combat climate change damage FUNAFUTI, TUVALU - AUGUST 15: From the air the ocean (L) and the logoon (R) and separated by a thin stip of land on August 15, 2018 in Funafuti, Tuvalu. The small South Pacific island nation of Tuvalu is striving to mitigate the effects of climate change. Rising sea levels of 5mm per year since 1993, well above the global average, are damaging vital crops and causing flooding in the low lying nation at high tides. Sea water rises through the coral atoll on the mainland of Funafuti and inundates taro plantations, floods either side of the airport runway and affects peoples homes. The nation of 8 inhabited islands with an average elevation of only 2m above sea level is focusing on projects to help it and its people have a future. Four of the outer islands are 97% solar energy dependent and the Tuvalu Government is working to achieve 100% renewable energy from wind and solar by 2025. Tuvalu's 11,000 inhabitants see the effects of climate change in their daily life. (Photo by Fiona Goodall/Getty Images for Lumix) Fiona Goodall Getty/Lumix Coral reefs: Trying to combat climate change damage A photo taken on April 4, 2019 shows fish swimming off the coast of Egypt's Red Sea resort of Hurghada. - In dazzling turquoise waters off Egypt's Red Sea coast, scuba divers swim among delicate pink jellyfish and admire coral -- but the rebounding tourism sector is worrisome for the fragile marine ecosystem. (Photo by Mohamed el-Shahed / AFP) (Photo credit should read MOHAMED EL-SHAHED/AFP/Getty Images) MOHAMED EL-SHAHED AFP/Getty Coral reefs: Trying to combat climate change damage Coral gardening A damselfish Sarah Frias-Torres Coral reefs: Trying to combat climate change damage Divers swim past a coral reef in the Egyptian Red Sea marine reserve AFP/Getty Coral reefs: Trying to combat climate change damage A puffer fish hovering above coral in the Egyptian Red Sea marine reserve AFP/Getty Coral reefs: Trying to combat climate change damage Researchers from the Interuniversity Institute for Marine Sciences in the southern Israeli resort city Eilat monitor coral growth while scuba diving on June 12, 2017 in the Red Sea off Eilat. Global warming has in recent years caused colourful coral reefs to bleach and die around the world -- but not in the Gulf of Eilat, or Aqaba, part of the northern Red Sea. At the Interuniversity Institute for Marine Sciences in southern Israeli resort city Eilat, dozens of aquariums have been lined up in rows just off the Red Sea shore containing samples of local corals AFP/Getty Coral reefs: Trying to combat climate change damage This photo taken on April 21, 2017 shows an aerial shot of part of mischief reef in the disputed Spratly islands on April 21, 2017. Philippine Defence Secretary Delfin Lorenzana flew to a disputed South China Sea island on April 21, brushing off a challenge by the Chinese military while asserting Manila's territorial claim to the strategic region. / AFP PHOTO / TED ALJIBE (Photo credit should read TED ALJIBE/AFP/Getty Images) TED ALJIBE AFP/Getty Coral reefs: Trying to combat climate change damage fish swimming off the coast of Egypt's Red Sea resort of Hurghada AFP/Getty

It also argues that the detrimental impacts of climate breakdown, such as increasing scarcity of food and water, will act as a catalyst on extant socio-political instabilities to accelerate disorder and conflict over the next three decades.

To usefully prepare for such an impact, the report calls for an overhaul in countries’ risk management “which is fundamentally different from conventional practice”.

“It would focus on the high-end, unprecedented possibilities, instead of assessing middle-of-the-road probabilities on the basis of historic experience.”

The research was authored by David Spratt, Breakthrough’s research director, and Ian Dunlop, a former international oil, gas and coal industry executive, who worked for Royal Dutch Shell and was chair of the Australian Coal Association.

Their paper offers what they say is a plausible scenario providing “a glimpse into a world of outright chaos”.

Based on lack of meaningful global action to rapidly extinguish all greenhouse gas emissions within the next decade, the authors sketch out a scenario in which global emissions peak in 2030.

In this case, using several existing studies, they hypothesise average global temperatures may reach 3C above pre-industrial levels by 2050.

The effect of this would be to realise the “hothouse Earth” scenario in which the planet would be heading for at least another degree of warming.

The reflective sea ice would melt, warming oceans further and raising sea levels rapidly. There would be “widespread permafrost loss and large-scale Amazon drought and dieback”.

The scenario reads: “The destabilisation of the Jet Stream has very significantly affected the intensity and geographical distribution of the Asian and West African monsoons and, together with the further slowing of the Gulf Stream, is impinging on life support systems in Europe.

“North America suffers from devastating weather extremes including wildfires, heatwaves, drought and inundation. The summer monsoons in China have failed, and water flows into the great rivers of Asia are severely reduced by the loss of more than one-third of the Himalayan ice sheet.

“Glacial loss reaches 70 per cent in the Andes, and rainfall in Mexico and central America falls by half.”

This scenario would also put the world on track for 5C of warming by 2100.

The paper notes that scientists have already warned that warming of 4C is incompatible with an organised global community, would be devastating to the majority of ecosystems, and has a high probability of not being stable. The World Bank said the planet may be “beyond adaptation” to such conditions.

“Even for 2C of warming, more than a billion people may need to be relocated and in high-end scenarios, the scale of destruction is beyond our capacity to model, with a high likelihood of human civilisation coming to an end,” the paper says.

The authors say “the world is currently completely unprepared to envisage, and even less deal with, the consequences of catastrophic climate change,” but also put forward policy recommendations which could help to mitigate the worst effects.

“To reduce this risk and protect human civilisation, a massive global mobilisation of resources is needed in the coming decade to build a zero-emissions industrial system and set in train the restoration of a safe climate.

“This would be akin in scale to the World War II emergency mobilisation.”