Climate change could make it dangerous for humans to go outside - we must act

Those claiming that concerns over climate change are rooted in hysteria are badly mistaken and unfortunately not restricted to the non-scientific community. The recent article by Craig Walton claiming that the risks of climate change have been exaggerated was unfortunately based on false claims. For instance, Dr Walton, who studies the origins of planets, wrote: "Claims of increasing frequency and danger of extreme weather events broadly lack strong scientific backing".

This is simply untrue. The most recent assessment by the Intergovernmental Panel on Climate Change, which reviewed the scientific literature, concluded: "Human-induced climate change is already affecting many weather and climate extremes in every region across the globe. Evidence of observed changes in extremes such as heatwaves, heavy precipitation, droughts, and tropical cyclones, and, in particular, their attribution to human influence, has strengthened".

Just this week, the Met Office published evidence that severe heatwaves and droughts are making extreme wildfires more frequent and intense worldwide.

Readers could forgiven for thinking Dr Walton dismissed as claims that climate change could threaten human civilisation, but his talk of "misinformation" was a statement of hope rather than knowledge. The truth is we do not know how human societies will cope with the climate we are creating.

The most recent analysis by the United Nations Environment Programme of countries policies and plans for tackling climate change concluded that global average temperature could be nearly 3 Celsius degrees higher by the end of this century compared with the period before the Industrial Revolution, when we started releasing carbon dioxide into the atmosphere by burning fossil fuels.

The Earth has not experienced such a global average temperature since the Pliocene Epoch about 3 million years, when the polar ice caps were much smaller than today and sea level was 5 to 25 metres higher than today.

As human civilisation was created during the past 10,000 years, and modern Homo sapiens appeared less than 250,000 years ago, Dr Walton assertions that we could cope with such a climate is little more than wishful thinking.

We should not be complacent about the risks that climate change is creating. Global average temperature is already about 1.4 Celsius degrees higher than before the Industrial Revolution, and the UK is suffering from more intense summer heatwaves and winter rainfall. This summer was the warmest on record, even warmer than the summer of 2022 when unprecedented temperatures of more than 40 degrees Celsius occurred for the first time in many parts of the country.

In some parts of the world, daytime temperature and humidity are now approaching levels at which it will be dangerous for people to be outside because they will not be able to cool down by sweating. As global temperature rises, these parts of the world could become difficult to inhabit.

There is no doubt that the impacts of climate change are increasing and harming lives and livelihoods around the world. These impacts will only stop worsening when the world reaches net zero emissions of greenhouse gases. Complacency or denial about these risks will only lead to more suffering.

There is no logical reason why any politician or scientist should reject the scientific evidence for climate change. Instead they should be leading public and policy debates about the best ways of tackling greenhouse gas emissions, and making our societies more resilient against those impacts of climate change that cannot now be avoided.

Bob Ward is the Policy and Communications Director at the Grantham Institute