Lethal humidity: why it’s an urgent climate issue for global leaders
With the effects of climate change becoming more prevalent there is a critical issue missing from global conversations. That issue is lethal humidity.
Lethal humidity is one of the greatest existential threats facing humanity, but most people have never heard of it. It has been undercounted and underreported globally, yet its impact is undeniable.
It is not just an environmental concern but a catalyst for an economic crisis. It is not just a future threat but a present reality.
We know that climate change is here and accelerating. We have already surpassed the 1.5˚C threshold established in the Paris Agreement. Now, scientists have confirmed, the past year (2023) was the hottest year on record by a substantial margin and likely the warmest in the last 100,000 years.
Science shows us that extreme humidity is also becoming more severe, frequent and widespread as a result of climate change. Humidity is the amount of water vapour present in the air. For every 1°C the planet warms, humidity rises by about 7 per cent as water evaporates from our oceans and waterways.
In a dry environment with low humidity, when temperatures rise, humans sweat to cool down. In these conditions, the upper limit to human survival is reached at around 54˚C.
However, with high humidity, this can happen at temperatures as low as 31-35˚C.
That’s because with high humidity and heat, our ability to regulate our body temperature becomes ineffective and we “cook” from the inside.
Without intervention, these conditions can lead to a rapid increase in core body temperature, triggering catastrophic health events such as heart attacks, strokes and even death.
Global leaders must take heed. When lethal humidity events occur, economic activity will fall markedly. The productivity loss, combined with the health crisis, will likely dwarf the death rates and economic impacts of geopolitical conflicts.
The responsibility to address lethal humidity is immense. The solution lies in global dialogue, cooperation and climate leadership.
The world’s largest economies – the US, China, and India – are well placed to lead the charge. They can use their influence, technological capabilities and financial resources to drive innovation, invest in infrastructure, set standards and shape a sustainable future for all.
Lethal humidity transcends borders and sectors, so it demands a unified response. The message is clear: the time for decisive action is now. The future of our planet and economies depend on it.