Death rate linked to extreme temperatures will increase under global warming: Study

The study was published in the journal, 'Environmental Research Letters'.

Death which is directly linked to climate temperature is called temperature-related mortality. In England and Wale, the hottest days of the year will increase by 42 per cent under a warming scenario of 2C from pre-industrial levels. This means an increase from present-day levels of around 117 deaths per day, averaged over the 10 hottest days of the year, to around 166 deaths per day. The findings underline the importance of keeping global warming levels below 2C.

At current global warming levels of around 1.21C, we see a slight decrease in temperature-related mortality in winter and a minimal net effect in summer, meaning that overall, at this level of warming we see a slight decrease in temperature-related mortality rate.

The team examined the impact of climate change on temperature-related mortality rates in England and Wales, focusing on the risk from the heat in summer and cold in winter. They found that as the global mean temperature increases, temperature-related mortality in summer will increase at a much faster, non-linear rate.

The rate of increase particularly speeds up at 2C of warming, with a much higher risk appearing beyond 2.5C. The researchers said that 3C warmings could lead to a 75 per cent increase in mortality risk during heatwaves.

When plotted on a graph, the relationship between temperature and mortality is roughly u-shaped, meaning that at extremely high temperatures, which the population is not used to, the mortality risk increases sharply for each degree rise of daily mean temperature.

The rate in winter will continue to decrease, although this doesn't take the side effects of extreme weather - such as storms - into account.

Lead author Dr Katty Huang (UCL Civil, Environmental & Geomatic Engineering) said, "The increase in mortality risk under current warming levels is mainly notable during heat waves, but with further warming, we would see risk rise on average summer days in addition to escalating risks during heatwaves. What this means is that we shouldn't expect past trends of impact per degree of warming to apply in the future. One degree of global warming beyond 2C would have a much more severe impact on health in England and Wales than one-degree warming from pre-industrial levels, with implications for how the NHS can cope."

In England and Wales, the temperature is associated with around 9 per cent of total population mortality, meaning that 9 per cent of all deaths during 2021 could be associated with temperature. Most of those deaths are related to the side effects of cold weather.

In order to isolate the effects of global warming on mortality risk, the researchers looked at the potential impact for the current population, without taking into account future changes such as average age and health conditions. (ANI)