This post explains how rising global temperatures are translating into a far more dangerous reality than the familiar 1.5°C or 2.0°C targets suggest. Drawing on recent science and attribution studies, I outline why averages are misleading, who is most at risk from extreme heat, how climate change and specific corporate emissions amplify deadly heat waves, and what urgent actions are needed to prevent further loss of life.
Why global temperature averages hide the deadly reality
Temperature averages used in policy debates can mask the increasing frequency, duration and intensity of extreme heat events. While global targets remain useful for long-term planning, they do not capture the local spikes and repeated heat waves that overwhelm communities and health systems.
How heat kills: the biology and the statistics
Extreme heat is not just uncomfortable — it is lethal. When core body temperature regulation fails, organ systems shut down through at least 27 different physiological pathways, from cardiovascular collapse to renal failure and heat stroke.
Recent years have shown the human cost: tens of thousands of deaths in Europe, Russia, South Asia, and even during the 2024 Haj pilgrimage.
Current estimates suggest annual global heat-related deaths likely exceed half a million.
In 2024 alone, climate change added an average of 41 extra days of dangerous heat worldwide, hitting small island and developing nations hardest.
Who bears the worst burden of extreme heat
The impacts of heat are unevenly distributed; some groups face far higher risk because of physiology, exposure, or economic constraints.
Addressing the crisis requires targeted protection for those most likely to suffer serious harm.
Vulnerable populations and lifetime exposure
Vulnerable groups include:
Future generations face steep increases in exposure: children born today may experience up to seven times more extreme heat events than those born in 1960.
Half of those born in 2020 will encounter unprecedented lifetime exposure.
The human fingerprint on heat waves
New methods in extreme event attribution have transformed our ability to link specific heat waves to human-caused climate change.
These techniques compare observed events with modelled worlds without anthropogenic emissions to quantify how much warming has amplified an event.
Attribution science and corporate responsibility
Attribution studies now show that most heat waves are directly intensified by climate change, and some events would have been virtually impossible without it.
A landmark 2025 study went further, tying particular deadly heat waves to emissions from major fossil fuel and cement producers.
It found that even the smallest of the so-called “carbon majors” were implicated in multiple otherwise impossible events.
Just 14 corporations and state-owned entities — including ExxonMobil, BP, Shell, Saudi Aramco and major Chinese coal producers — produced sufficient emissions to be linked to over 50 extreme heat waves each.
This effectively makes them directly responsible for mass climate-related harm.
What must change now
Confronting the heat crisis requires a two-track approach: aggressive emissions reductions to limit worsening extremes, and rapid adaptation to protect people now.
Both scientific precision and moral clarity are essential.
Practical actions and policy priorities
Key priorities include:
We cannot treat heat as a background statistic any longer.
The science now makes clear both the scale of the threat and the actors who enabled it.
Here is the source article for this story: Who is responsible for heat that kills?