I learnt that fine weather meant the sunny breaks in the cloudy, garden-sprinkler climate that made Britain a fat, fertile island and mildly depressed its people.

This summer might change that. In the month that I've been here, the evidence of drought is everywhere; brown lawns, dry hedgerows, hosepipe bans, cheap fans, half-naked, buxom Englishmen and irritable double-decker drivers stewing in their plexiglass cubicles. The BBC's report on the drought opened with "Hyde Park looks more like the Serengeti and the green belt has turned yellow." We drove from Brighton to London and the downs and wealds in between had been reduced to scrub. We stopped for lunch at a pub in Hambledon, the birthplace of cricket's early laws, and the Broadhalfpenny Down that used to be Hambledon Cricket Club's home ground was a sere, brown bowl sloping away from its mottled square.

England is living through a textbook case of climate change. A high pressure dome has settled over the country, trapping heat below it and preventing adjacent rain-bearing winds from dispersing the heat. The jet stream, best thought of as a high altitude stream of air, that in normal years would push the dome of heat away, is now too sluggish to do its job. The temperature difference between the equator and the poles that gave the jet stream its momentum has shrunk because polar ice caps have been heating up faster than the rest of the planet. The result is that what in earlier years would have been a spell of glorious sunshine that peaked at 28ºCelsius is now a properly Indian summer that threatens 40ºC.

The political Right in England, as elsewhere in the world, opposes any policy that might mitigate climate change. Politicians like Kemi Badenoch, the leader of the Opposition, and Richard Tice, the leader of an extreme Right party, have made opposing Net Zero, till recently a Conservative Party goal, their political credo. They argue that given the scale of Asian emissions, Britain achieving Net Zero would make no difference to global warming.

This is an example of how infantilised politics in the West has become; Western countries like Britain and the United States of America have decided that blaming Daddy China for current emissions lets them free ride on that country's massive investment in clean renewable energy sources. Even a decade ago, there used to be an acknowledgment of the West's responsibility for historical emissions and a recognition that tackling global warming needed a global compact negotiated in good faith.

That's gone now. The only national politician in England who believes in Net Zero is Edward Miliband, so Andy Burnham has made him foreign secretary to make sure he can't do anything about it. Miliband couldn't become chancellor because Burnham came to believe he would spook the bond markets with his incendiary ecological beliefs. Tice's view that the English should "adapt" to climate change by enjoying England's Mediterranean summers and its Home County vineyards represents Britain's political consensus. He says out loud what Labour's Centrist leadership is too embarrassed to own up to. The trouble is that global warming won't be a gradual process that benignly turns the Isle of Wight into Ibiza even in countries located in temperate latitudes. Raging wildfires of the sort that have broken out in France, Spain, even Wales are the likelier consequences.

A preview of the apocalypse that lies in wait for a procrastinating world made the headlines midweek when a glacier collapse in Tibet resulted in cascading floods that killed hundreds of people. The world's grandest mountain ranges - the Alps, the Andes, the Himalayas - are heating up faster than the lowlands they look over. As glacier ice warms up, the chances of a glacier fracturing and releasing gigantic quantities of ice, rubble, mud and water into river systems unable to contain them rise. This seems to have happened on the Nepal-China border.

A sheared-off glacier set off a tsunami of mud and water that swallowed river valleys and swept away pilgrim towns. More than five hundred people are confirmed dead and nearly three thousand are missing. Given global warming, experts warn that catastrophic events like this one are likely to recur.

What is terrifying is that these receding, collapsing glaciers presage an even more existential threat to life in South Asia, the most densely-populated region in the world. A majority of the two billion people who live there depend on perennial, glacier-fed Himalayan rivers for drinking water, irrigation and hydroelectric power, for life and livelihood. Pakistan and North India are already amongst the most heat- and water-stressed regions in the world. It won't take much for their summers to become literally unbearable as wet bulb temperatures push the limits of the human body's tolerance.

A global geopolitics that abandons collective action on climate change in the name of national self-interest or inevitability is dabbling in a suicidal form of knowingness. First, even if the world is past the point where it can limit the post-industrial rise in global temperatures to less than two degrees, individual countries still need concerted global action to slow the rate of the rise and to mitigate the disasters that global warming will bring in its train. Second, what starts in, say, South Asia won't stay in South Asia. The South Asian diaspora, already by some estimates the largest in the world, will become exponentially larger if the polycrisis, the intersecting economic, military and ecological crises that define our times, metastasizes on account of unregulated warming. For the West to do everything it can to keep the South livable would be an act of enlightened self-interest.

That said, the principal responsibility for slowing and mitigating climate change in South Asia vests in South Asian states. Bangladesh has led the way in climate adaptation. Its community-based cyclone warning systems and shelters are exemplary achievements for a poor country. India, the largest country in the region, has invested relatively heavily in renewable energy. But its government's willingness to deregulate the country's forests and natural resources to favour crony conglomerates, its unwillingness to rein in the construction and transport lobbies that have made India's cities polluted hellholes, its addiction to sectarian politics and its near-uniformly hostile relations with its subcontinental neighbours make Indian environmental leadership in South Asia a dangerously remote prospect.

mukulkesavan@hotmail.com