Hotter Summers Are Coming. Are We Prepared?

Over five years ago, B.C. suffered a heat dome in late June and early July 2021.

According to the BC Coroners Service, 619 people suffered heat-related deaths during the heat dome. Ninety per cent were aged 60 or older; 91 per cent had at least one chronic disease. A third lived in what the coroner’s report called “neighbourhoods that were most socially deprived.”

Clearly, the old, ill and poor are the most vulnerable to heat waves, especially those with high humidity.

Now a new research report has been published in the Lancet Planetary Health, a highly respected medical journal. The report argues that not only are the old most vulnerable, but the scale of the problem is far worse than we imagined.

The report, called “Exceeding Human Heat Tolerance in a Warming, Ageing World: A Global Projection Modelling Study,” estimates which age groups are most susceptible in heat regimes ranging from 1.5 C to 4 C above late 19th-century levels, before human-caused carbon dioxide emissions were big enough to cause serious warming.

Predictably, it finds older people are most likely to die in heat waves with high humidity.

But the report avoids one critical point: what’s happening to everyone else, not just the old, as global temperatures rise.

Another, very recent report, “Canada’s Changing Climate Report 2026,” says Canada’s temperature is already 2 C higher than pre-industrial levels, meaning people aged 65 or older are susceptible right now.

That means unprotected older people experience uncompensable heat stress, or UHS, if heat and humidity are both high enough and persistent enough.

Uncompensable heat stress happens when high environmental temperatures and humidity mean that the body can’t cool itself down and maintain steady temperatures. That means sweating fails to cool the body — and a human body over 65, the authors note, has “reduced sweat gland output, attenuated cutaneous vasodilation, and decreased cardiac output.”

In other words, older people can’t sweat enough and can’t get enough blood to the skin to help cool their bodies. High heat puts dangerous stress on their hearts.

More than two billion over 65

The authors of the Lancet article point out that by 2050, more than two billion people on the planet will be 65 or older — that is, born in 1985 or earlier. Half of them will be living in southern and eastern Asia, in the countries from the Persian Gulf to the Yellow Sea.

They, and we, will look back on 2026 as the good old days, when the global average temperature was only 1.5 C above late 19th-century temperatures. In the next quarter-century, the global climate will warm by at least another half a degree, and perhaps more.

Every summer, for the foreseeable future, will be hotter than the one before.

That certainty raises questions. Who, in the summer of 2050, will monitor the oil pipelines and reservoirs in the Gulf states and Iran? Who will crew the tankers, and will they even be able to take on cargoes of oil and gas? Who will want those cargoes, and what will they pay for them?

According to the International Centre for Integrated Mountain Development, the glaciers of the Hindu Kush Himalaya help feed 10 great river systems, including the Indus, Ganges, Irrawaddy, Mekong, Yangtze and Yellow rivers. Almost two billion people now depend on the water in those river basins. Who will plant the crops across India, Bangladesh, Myanmar and the Southeast Asian countries?

The authors of the global heating study estimate that, “under the 1.5 C global warming scenario, widespread UHS for young adults was largely confined to a narrow strip of the Indo-Gangetic Plain, with annual exposure of 41 to 84 hours.”

Even so, everyone would be exposed to potentially deadly heat. If the old could not live, the middle-aged would be at risk. And the young could not work.

The report lays out a bleak scenario for global temperature increases. For temperatures rising under 2 and 3 C, the authors write, “exposure expanded across the broader Indo-Gangetic Plain, the North China Plain, the Sahel, and the Persian Gulf.” Things get worse with temperature increases under 4 C, where uncompensable heat stress for young adults extends to the eastern United States and parts of South America, “with annual totals exceeding 180 hours across large regions of eastern China, the Persian Gulf coast, and the Sahel, and surpassing 540 hours in Indo-Gangetic Plain hotspots.”

The global heating report’s predictions are based on a couple of implicit assumptions: that human-caused global emissions will keep rising, and that economies will continue to function much as they do today despite the heat.

360 million elderly in China alone

But consider the case of China under these conditions. The United Nations estimates that by 2050 China’s population will be about 1.18 billion people, down 204 million from the 2020s. Those over age 65 will grow to 31 per cent of the total population — some 360 million, all born in 1985 or earlier.

Even under the best of conditions, it will be hard for a shrinking working-age population to look after itself, its own kids and 360 million old people, all of them with at least minor health problems and many requiring non-stop medical care.

But China won’t have the best of conditions. Like everywhere else in the world, it will have droughts, floods, wildfires, earthquakes, labour shortages, crop failures and political and economic turmoil as a result. China’s neighbours, from the Koreas to Vietnam to India and Pakistan, will be struggling with similar problems.

In all these countries, and many others, a global temperature increase of 2 C will be fatal to many working-age people as well as seniors.

By the time global temperatures rise by 3 or 4 C, it’s hard to imagine any country with a fully functional economy that engages in international trade.

Industrial CO2 emissions could fall, as they did early in the pandemic, but by 2050 emissions from wildfires and melting permafrost will build up yet more CO2. “Canada’s Changing Climate Report 2026” predicts a 5 C increase in Canada’s average temperature between 2081 and 2100 if climate policies remain as they are.

We are already at 2 C in southern Canada, and the Arctic is at 2.5 C. A sharp reduction in emissions, the authors say, could keep us at a 3.5 C increase. Even then, the effects of global heating will be “irreversible,” they say.

Still, societies will survive if they organize themselves to protect not just their seniors but everyone, starting now.

Yes, old people should be able to count on cool shelter. But they should also be able to count on functioning pharmacies and hospitals, supermarkets and trash pickup.

As we saw in the early months of the COVID-19 pandemic, access to health care is critical. So are the supermarket employees who stock shelves, and the truck drivers who bring food to markets.

They need to be kept cool as well; if they can’t, and the economy fails altogether, the old will suffer whatever the temperature may be.

So will everyone else.

We have the resources to keep old people cool. The best way to do so is to ensure that we keep everyone cool, however high the temperature rise.