On Sunday morning hundreds of politicians, government officials and scientists will gather in the grandeur of the International Congress Centre in Katowice, Poland. It will be a familiar experience for many. For 24 years the annual UN climate conference has served up a reliable diet of rhetoric, backroom talks and dramatic last-minute deals aimed at halting global warming.

But this year’s will be a grimmer affair – by far. As recent reports have made clear, the world may no longer be hovering at the edge of destruction but has probably staggered beyond a crucial point of no return. Climate catastrophe is now looking inevitable. We have simply left it too late to hold rising global temperatures to under 1.5C and so prevent a future of drowned coasts, ruined coral reefs, spreading deserts and melted glaciers.

One example was provided last week by a UN report that revealed attempts to ensure fossil fuel emissions peak by 2020 will fail. Indeed the target will not even be reached by 2030. Another, by the World Meteorological Organization, said the past four years had been the warmest on record and warned that global temperatures could easily rise by 3-5C by 2100, well above that sought-after goal of 1.5C. The UK will not be exempt either. The Met Office said summer temperatures could now be 5.4C hotter by 2070.

At the same time, prospects of reaching global deals to halt emissions have been weakened by the spread of rightwing populism. Not much to smile about in Katowice.

Nor will the planet’s woes end in 2100. Although most discussions use the year as a convenient cut-off point for describing Earth’s likely fate, the changes we have already triggered will last well beyond that date, said Svetlana Jevrejeva, at the National Oceanography Centre, Liverpool. She has studied sea-level rises that will be triggered by melting ice sheets and expanding warm seawater in a world 3-5C hotter than it was in pre-industrial times, and concludes these could reach 0.74 to 1.8 metres by 2100. This would be enough to deluge Pacific and Indian Ocean island states and displace millions from Miami, Guangzhou, Mumbai and other low-lying cities. The total cost to the planet could top £11trillion.

Even then the seas will not stop rising, Jevrejeva added. “They will continue to climb for centuries even after greenhouse-gas levels have been stabilised. We could experience the highest-ever global sea-level rise in the history of human civilisation.”

Vast tracts of prime real estate will be destroyed – at a time when land will be needed with unprecedented desperation. Earth’s population stands at seven billion today and is predicted to rise to nine billion by 2050 and settle at over 11 billion by 2100 – when climate change will have wrecked major ecosystems and turned farmlands to dust bowls.

Facebook Twitter Pinterest Residents of Anaroro, Madagascar, paddle through the flooded streets in the aftermath of a cyclone. Photograph: Gregoire Pourtier/AFP/Getty

Unfortunately many experts believe Earth’s population will actually peak well beyond 11 billion. “It could reach 15 billion,” said Sarah Harper, of Oxford’s Institute of Population Ageing. “All sorts of factors suggest women, particularly in sub-Saharan Africa, will still want to have relatively high numbers of children and this might keep the world’s population approaching 15 billion rather than 12 billion.”

The world will have double its present numbers – but with hugely reduced areas of fertile land to provide food. We will be living in a shrunken, scorched planet bursting with human beings. Somaliland gives a grim vision of this future.

In the past few years climate change has killed 70% of its livestock and forced tens of thousands of families to flee from its scorched interior to live in refugee camps. “You can touch it, the climate change, in Somaliland. It is real. It is here,” the country’s environment minister, Shukri Ismail Bandare, said in the Financial Times last week.

Sudan and Kenya are also victims of a drought that has dried the Horn of Africa faster than at any other time in the past 2,000 years. Similarly, in Vietnam, thousands a year are abandoning the once fertile Mekong Delta as rising seawater pollutes paddy fields. By 2050, the World Bank says more than 140 million will become climate refugees.

It will be bad for humans, but catastrophic for Earth’s other inhabitants. Arctic ice loss threatens polar bears, droughts imperil monarch butterflies, and koala habitats are being destroyed by bush fires. In all, about a sixth of all species now face extinction, say scientists, although in the end no creature or plant will be safe. “Even the most resilient species will inevitably fall victim as extreme stresses drive ecosystems to collapse,” said Giovanni Strona of Europe’s Joint Research Centre in a report last week on climate change.

Scientists warned more than 30 years ago that such a future lay ahead, but nothing was done to stave it off. Only dramatic measures are now left to those seeking to save our burning planet, and these can have grim political consequences. In France, for example, President Macron’s new levies on fossil fuels, introduced to cut emissions and to fund renewable energy projects, triggered riots. Had only modest changes been enacted a few decades ago there would be no trouble today, say analysts.

But the most telling example is provided by the US, which has emitted about a third of the carbon responsible for global warming. Yet it has essentially done nothing to check its annual rises in output. Lobbying by the fossil fuel industry has proved highly effective at blocking political change – a point most recently demonstrated by groups such as the Competitive Enterprise Institute and the Heartland Institute, which helped persuade President Trump to pull out of the Paris agreement, thus dashing the planet’s last hope of ecological salvation. “The coalition used its power to slow us down precisely at the moment when we needed to speed up,” said the environmentalist Bill McKibben in the New Yorker. “As a result, the particular politics of one country for one half-century will have changed the geological history of the Earth.”

Florida

No region of the US has more to lose from climate change than southern Florida. If scientists’ worst predictions are realised, an entire metropolitan area, currently inhabited by more than six million people, is likely to be swamped by a 1.5-metre sea-level rise before the end of this century, a rise that could see the tourist mecca of Miami simply disappear.

It’s a doomsday scenario that has united the leaders of Miami-Dade county and the cities of Miami and Miami Beach in an attempt to find solutions to the most severe effects of rising oceans before it is too late. Their plan to combat the physical, economic and social challenges of climate change, as part of the global 100 Resilient Cities programme, will play a key role in determining whether the low-lying region will still be habitable in the coming decades or surrendered to the ever-rising Atlantic.

“It’s a problem that can be managed, it’s not a problem that can be fixed and you walk away from,” said Susanne Torriente, chief resilience officer for Miami Beach, where hundreds of millions of taxpayers’ dollars have already been spent elevating roads, constructing higher sea walls and investing in modern, high-capacity pumps and stormwater drainage systems.

“Every generation will add to the work that we have begun,” Torriente says. “We are always learning, it’s a constant process of learning, re-evaluating and improving.”

Facebook Twitter Pinterest A flooded street in Miami Beach, Florida, one of the areas of the US at greatest risk from rising sea levels. Photograph: Joe Raedle/Getty Images

Up to a million Florida homes, worth an estimated $371bn (£290bn, are at risk of tidal flooding by 2100, one recent study calculated, but the threats facing the greater Miami region are not just coastal. Hurricanes are becoming more powerful because of global warming, say scientists, who point to the destruction wrought by Hurricane Michael in October, while the combination of a low water table and high “king” tides – occurring in autumn – causes regular inland flooding even on dry days.

This means that the new joint action plan being worked on by city and county officials has to be further-reaching than anything that has preceded it, Torriente says. “Our resilience journey began with the climate work, the storm water, [but] this strategy will be much broader and will be defining resilience not only in terms of climate and flooding, but also mobility and housing, property, and how to recover quickly in the event of a hurricane in south Florida.”

These moves reflect the sense of urgency being felt in Florida, where the state leadership has been criticised for neglecting the environment. Its newly elected senator, Rick Scott, banned staff from using the term climate change during his time as governor of Florida, and will be a close Washington ally of President Donald Trump, who took the US out of the Paris climate agreement.

“We’ll be much more successful if we have more cooperation and more attention at all levels of government, [because] it’s a problem for all of us,” Torriente says. “But we do what we can. Everything we are doing is funded locally, so we can continue to invest.”

Richard Luscombe, Miami

Madagascar



It’s a 45-minute canoe journey along the coast from regional capital Morombe to Kivalo in south-west Madagascar. Children frolic in the water, palm trees sway, and fishing nets hang along the beach. This tranquillity is deceptive, however – for Madagascar is ranked as one of the countries most vulnerable to climate change. Higher temperatures, extended drought periods in the south, intensification of cyclones and rising sea levels are all forecast. For good measure, the country’s pervasive poverty restricts its capacity to adapt to such changes.

In Kivalo, this is already a familiar picture. “The southern wind used to start in January and last until July,” says Bikison Thomas, a fisherman. “But it’s still going now in November.” On very windy days, he cannot put out to sea. “There is also more fog,” he adds. Overfishing, higher sea temperatures and the loss of mangrove, a crucial habitat for fish stocks, are also reducing catches.

Facebook Twitter Pinterest Villagers deal with the floods in Madagascar after a tropical cyclone. Photograph: Alain Iloiniaina/Getty Images

The Madagascar government is aware of the country’s vulnerability and has ratified the Paris agreement. Climate change is listed in every major policy document but budgets usually fall short of producing effective measures, a point that is demonstrated dramatically down the coast in the town of Morondava, where hotels are grappling with sea-level rise.

Two years ago, Chayune Badouraly bought the Coco Beach hotel. It had a few bungalows and a lovely beach. Badouraly added more bedrooms, a reception area and a restaurant.

But in September, powerful tides destroyed two of his bungalows, and the sea has not returned to its previous level. “We used to have 150 metres of beach,” he says bitterly. “Now it’s minus five.”

Although there are plans to build sea defences, Badouraly says that could take months, even years, so he’s taken the problem into his own hands and built a 60-metre-long sea wall, a mixture of stone blocks, steel rods and sandbags. “I knew we had coastal erosion problems, but I didn’t think it would be that bad,” he adds. “I would never have bought.”

Emilie Filou, Madagascar

Antarctica



It is hard to get a grip of the sheerscale of the Thwaites glacier in west Antarctica. It’s more than 300 miles long and 200 wide – and more than a mile thick. It drains an area of ice that is larger than England and stealthily slides towards the sea by several metres every day. Only from satellite images have we understood the shape and power of this ice monster.

These now show the beast is waking up. Thwaites’s uptake of falling snow was once matched, fairly finely, by snow and ice being lost as icebergs. Now it has begun to flow faster, along with some of its neighbouring glaciers. More ice is being lost into the ocean than is being replaced, speeding up global sea-level rise.

The cause of the disruption at Thwaites is straightforward, researchers have discovered. Increasing amounts of warm ocean water coming from the north have been melting the floating parts of the glacier and this, in turn, is letting the inland glacier run more quickly into the sea. This much we know, but we have still to understand how this process is likely to accelerate. At present, Thwaites contributes around 4% of observed sea-level rise, but it is widely agreed that this could grow exponentially. Indeed, some glaciologists believe that a complete collapse of the Thwaites glacier over coming centuries is now inevitable – and that would raise global sea level by several metres, drowning coastal ecosystems around the world, damaging coastal investments and displacing millions of people.

Facebook Twitter Pinterest The field support team who will be setting up the camps on Thwaites Glacier, Antarctica. Photograph: Tim Gee/British Antarctic Survey

Research on the ice and frigid waters around Thwaites Glacier is urgently needed but carrying that out is tough. Even by Antarctic standards, this area is cold and remote. I have been working in Antarctica for more than 30 years, and I’ve never managed to reach Thwaites. However, the UK and US governments have agreed to send in scientists as part of the International Thwaites Glacier Collaboration. We are finally going to get the chance to understand this waking monster. At the moment, it is merely yawning and stretching. The question we must answer, urgently, is whether it is about to wake up and roar.

David Vaughan, British Antarctic Survey

Great Barrier Reef



Coral reefs cover a mere 0.1% of the world’s ocean floor but they support about 25% of all marine species. They also provide nature with some of its most beautiful vistas. For good measure, coral reefs protect shorelines from storms, support the livelihoods of 500 million people and help generate almost £25bn of income. Permitting their destruction would put the planet in trouble – which is precisely what humanity is doing.

Rising sea temperatures are already causing irreparable bleaching of reefs, while rising sea levels threaten to engulf reefs at a faster rate than they can grow upwards. Few scientists believe coral reefs – which are made of simple invertebrates related to sea anemones – can survive for more than a few decades.

Yet those who have sounded clear warnings about our reefs have received little reward. Professor Terry Hughes, a coral expert at James Cook University in Queensland, Australia, recently studied the impact of El Niño warmings in 2016 and 2017 on Australia’s Great Barrier Reef, the world’s largest coral reef and its largest living entity – and wept when he saw the damage.

Facebook Twitter Pinterest Close to half the corals on the Great Barrier Reef have died in the past three years, according to expert Prof Terry Hughes. Photograph: Greg Torda/ARC Centre of Excellence for Coral Reef Studies

“The 2016 event killed 30% of corals, the one a year later killed another 20%. Very close to half the corals have died in the past three years,” he said recently.

For his pains, Hughes has faced demands from tourist firms for his funding to be halted because he was ruining their business. “The Australian government is still promoting new developments of coal mines and fracking for gas,” Hughes said, after being named joint recipient of the John Maddox prize, given to those who champion science in the face of hostility and legal threats. “If we want to save the Great Barrier Reef, these outdated ambitions need to be abandoned. Yet Australia’s greenhouse gas emissions are rising, not falling. It’s a national disgrace.”

This grim picture is summed up by the ethnographer Irus Braverman in her book Coral Whisperers: “The Barrier Reef has changed for ever. The largest living structure in the world has become the largest dying structure in the world.”