Turks & Caicos damage, wildfire in British Columbia and flooding in BangladeshTurks & Caicos after Hurricane Irma, wildfires in British Columbia, floods in Bangladesh [photos: US Command, B.C. website, Save the Children. Montage by Debbie Ransome]

The growing potential for climate change to wreak misery on millions and undo decades of infrastructure development within hours and was underlined by a series of extreme weather events devastating countries across the Commonwealth in August and September.

As if to confound the climate-change deniers of the Trump administration, two category-4 hurricanes made landfall in the US in the same season for the first time. Hurricane Harvey set its own new records as it tore through the southern United States in August, dumping 127cm (50in) of rain on Texas and Louisiana (four times more than Hurricane Katrina in 2005, itself the costliest and one of the deadliest US natural disasters ever). No sooner had that storm petered out than Hurricane Irma came barrelling in at speeds of 300km (185mph) across the Caribbean, breaking records in turn: the highest winds ever recorded in the Atlantic Ocean and the most sustained tropical cyclone the world has ever seen among others.

Barbuda lost 90% of its buildings, with half of the population left homeless. The prime minister of Antigua and Barbuda, Gaston Browne, said the island had been left ‘barely habitable’. Several British overseas territories – Anguilla, Tortola, largest of the British Virgin Islands, and the Turks and Caicos Islands – were all badly hit by Irma. The French ‘overseas collectivities’ of St Martin and St Barthélemy were also devastated, the New York Times reported. ‘We desperately need help as soon as possible: food, water, shelter. I’m extremely concerned about health and safety – there is sewage absolutely everywhere,” one resident of Tortola told the Guardian. ‘It’s worse than anyone could have imagined. The country is going to need some serious help … The town has been emptied; every shop has been looted.’ With the UK already criticised for its ‘inadequate’ response to the disaster, aid efforts to stricken islands were further frustrated by the imminent arrival of the next hurricane of the season, Jose, only days behind Irma. In its wake came Hurricane Maria. This time Dominica took the brunt of the category-five hurricane, killing nearly 30 people, cutting all communication with the world and damaging 80% of buildings. The United Nation’s World Food Programme, which estimated that aid would be needed for 25,000 people for three months, said: ‘Dominica has been badly battered and needs to be rebuilt.’

The floods caused by Harvey were a once-in-a-1,000-year event, the Washington Post declared, but rather undermined this by stating elsewhere that Houston had suffered its third ‘once-in-500-years’ flood in three years. In fact, researchers from Massachusetts Institute of Technology and Princeton University found, these supposed meteorological freaks are likely to come along every decade from now on. But for all the TV footage of destitute citizens of the world’s richest country sitting in flooded despair, and the storm’s estimated $150bn repair bill, Harvey killed relatively few people, the Associated Press concluded. By mid-September 82 deaths had been reported; in 2005, Hurricane Katrina claimed more than 1,800 lives. The death toll for Irma had reached 81, the majority of them in the Caribbean.

By contrast, the monsoon floods of biblical proportions that swept through south Asia at the same time affected at least 45 million people, according to the United Nations, and had killed at least 1,300 in India, Nepal and Bangladesh. Save the Children said 18,000 schools had been destroyed, halting the education of 1.8 million children.  The Indian states of Assam, Bihar, Odisha, West Bengal were all flooded, the New York Times reported. Even Mumbai, India’s financial capital, was paralysed as waist-deep floodwaters swamped public transport, inundated the King Edward hospital and caused a building to collapse.

In Nepal 90,000 homes were destroyed in what the United Nations called the worst flooding in a decade, Reuters said, while in Bangladesh the flooding submerged more than a third of the low-lying country. The International Federation of the Red Cross and Red Crescent Societies (IFRC) said it was the fourth significant flood to have hit Bangladesh this year, affecting 7.5 million people and destroying 700,000 houses, the Guardian reported. Bangladesh had already lost about 1m tonnes of rice in flash floods in April. ‘I could not find a single dry patch of land,’ the IFRC’s Matthew Marek said, after making an aerial assessment of the worst-affected areas.

In a grim irony, drought threatened the south of India as it faced a second year of below-average rainfall. In an article headlined ‘As a river dies, India could be facing its greatest human catastrophe ever’, Channel NewsAsia highlighted the story of one of 350 farmers to have died at their own hands as  Tamil Nadu state endures its worst drought in 140 years. Their plight is repeated across the country with a study published in July by the PNAS journal suggesting that the suicides of 60,000 Indian farmers over the past 30 years could be attributed to the warming climate.

Also in August, at least 1,000 people in Sierra Leone were killed or missing after torrential rains and widespread flooding caused a huge mudslide on the outskirts of the capital, Freetown, the Guardian reported. The country faced ‘a long slog to recovery’, the Los Angeles Times said, with thousands left homeless, a lack of drinking water and the breakdown of already rudimentary sanitation threatening to bring malaria, typhoid and cholera in the mudslide’s wake.

And while the south-east corner of North America was waist-deep in water, the west baked. Heat records set in the 1890s were broken in Canada’s province of British Columbia. More than 825 wildfires had forced the evacuation of more than 45,000 people by August. With the summer heat yet to peak, the Vancouver Sun reported that it was already the worst fire season since 1958, with 5,000 sq km destroyed. Meanwhile, the Solomon Islands gave a glimpse of a likely scenario for other low-lying countries as they face inundation by sea levels rising at a rate three times higher than the global average over the last 20 years. Scientists showed last year that five islands in the archipelago had disappeared and another six were so badly eroded that they were abandoned.

Outlining steps to help millions affected by the monsoon floods, the Indian prime minister, Narendra Modi, noted the ‘big negative impact’ of ‘climate change, altered weather cycles, and transformations in the environment’, Reuters reported. In contrast, for the head of the US Environmental Protection Agency, Scott Pruitt, the critical response to Hurricane Harvey was to shut down talk linking the increasing ferocity of hurricanes with climate change: ‘For opportunistic media to, without basis or support, just to simply engage in a cause-and-effect type of discussion, and not focus upon the needs of people, I think is misplaced.’ There is a long, dishonourable tradition of American climate-change deniers, such as the Heartland Institute and Cato Institute, desperately trying to detach extreme weather events from the idea of global warming and trying to remove the debate from the school curriculum. The US shock jock Rush Limbaugh sees even reporting on hurricanes as a left-wing conspiracy.

However, as one environmental scientist argued in the Guardian, denying such climate links only worsens future suffering. And, as another, Prof Michael Mann of Pennsylvania State University, pointed out: ‘While we cannot say climate change “caused” [it] … climate change worsened the impact of Hurricane Harvey.’ Climate change is ‘amplifying the damage done by hurricanes’, the science site Climate Signals points out, as global warming heats sea surfaces, thereby increasing the energy that hurricanes draw on as they grow more powerful.

As extreme weather records tumble, the Commonwealth’s small islands and huge states alike will have to rebuild ever more often after natural disasters, rueing how easily progress can be stalled. The Commonwealth must help member states draw up plans on how to adapt and mitigate the worst effects of climate change. As the eminent climate scientist Prof Lonnie Thompson put it in 2010: ‘Global warming is here and is already affecting our climate, so prevention is no longer an option. Three options remain for dealing with the crisis: mitigate, adapt, and suffer … And the longer we delay, the more unpleasant the adaptations and the greater the suffering will be.’

[This article was updated on 3 October 2017]