The provocative report is published by a British NGO, Forum for the Future, which carries out strategic analysis on sustainable development on behalf of business.

It sketches a wide range of social consequences from today's global warming crisis, derived from published studies and consultations with more than 60 climate-change specialists. It is published in collaboration with the technology giant HP.

"What we do now could determine the fate of billions of people. These could be the most important years in history," said Peter Madden, Forum for the Future's chief executive, explaining the point of the document.

The study, "Climate Futures," sees five possible scenarios for 2030:

-- ENERGY EFFICIENCY: A swift, peaceful transition to a consumerist economy where heat-trapping carbon emissions are low.

"Artificially-grown flesh feeds hundreds of millions, supercomputers advise governments, and eco-concrete walls protect the USA's eastern seaboard, generating power from the waves and tides," the report suggests.

-- SERVICE TRANSFORMATION: Carbon pollution has become so dangerous that a hefty price is imposed on emissions. People share cars, washing machines and other products, and transport has become so expensive that international sports events are staged virtually, in cyber-space.

"NATO is ready to go to war if necessary to enforce the 2020 Beijing Climate Change Agreement, and water shortages have already forced the abandonment of Central Australia and Oklahoma," Forum for the Future says. "Booming mega-cities are only just managing to cope and fuel poverty is a huge problem."

-- REDEFINING PROGRESS: After a decade-long global depression following the 2008 crash, governments keep a tight regulatory hand on the economy and encourage citizens to put greater priority on quality of life than making money.

"Countries compete to score highest in the World Bank's Wellbeing Index and the EU (European Union) Working Time directive sets a limit of 27.5 hours a week," the report suggests.

"The trend is towards economic resilience and simpler, more sustainable lives, but 'free-riders' plunder resources, several big cities have set up as 'havens of real capitalism' and some governments are aggressively pro-growth."

-- ENVIRONMENTAL WAR ECONOMY: Efforts to craft a post-Kyoto Protocol climate pact beyond 2012 break down.

The treaty is signed only in 2017, and lost time and worsening climate problems force governments to take extraordinary measures, placing their economies on a war footing to tackle greenhouse-gas emissions.

"Civil liberties have been stripped away. You need a licence to have children in some countries, and if you go over your household energy quota the carbon monitor will turn off your appliances," this scenario suggests.

"Climate refugees from Bangladesh and the Pacific islands make up 18 percent of New Zealand's population and are expected to boost Antarctica's population to 3.5 million by 2040."

-- PROTECTIONIST WORLD: A post-Kyoto deal for 2012 collapses amid accusations of cheating and undeclared power stations. Countries launch go-it-alone strategies and fight wars over scarce resources. Mercenaries, fighting for nations and businesses, wage war over oil, gas and gold in the thawing Northwest Passage in the Arctic.

"Violent factions exploit the chaos to launch devastating bio-chemical attacks," says this grim scenario.

"Cyber-terrorists operating from safe havens in failed states have already bankrupted two multinationals. Action to mitigate climate change is all but abandoned."

All rights reserved. copyright 2018 Agence France-Presse. Sections of the information displayed on this page (dispatches, photographs, logos) are protected by intellectual property rights owned by Agence France-Presse. As a consequence, you may not copy, reproduce, modify, transmit, publish, display or in any way commercially exploit any of the content of this section without the prior written consent of Agence France-Presse.