Contents page 1 — “The number of deaths due to heat does not rise” side 2 — “air conditioning systems are the most efficient adjustment” On a page
From the 3 read. to 14. December discuss politicians and state representatives at the UN climate change conference, as the 1.5-degree target. On this occasion, a TIME to ask ONLINE in a focus, not only what are the consequences of climate change already, but also: limit the global warming? Already today, significant health consequences, we have spoken with the epidemiologists Shakoor Hajat.
TIME ONLINE: suggests A recently released report once again that climate change is also a health problem (The Lancet: Watts et al., 2018). What that means specifically, and that makes problems?
Shakoor Hajat: We see the effects of climate change already. Approximately since the seventies, the average temperature increases, and we observe that the number of deaths rises by heat. In addition to such direct effects, due to heat, but also by the cold, and extreme events such as floods or hurricanes – betting, we also see indirect effects. The pollen season has changed, for example, what people feel, the hay fever. Also infectious diseases that are transmitted by mosquitoes or ticks, such as, for example, Dengue and Malaria are spread over larger regions. Also diseases via food or drinking water, non-transferable and diarrhoea, Cholera, Campylobacter and Salmonella, could be a result of climate change more frequently. And then there are indirect effects such as malnutrition, which can be a consequence of drought, but also Migration and social changes such as political instability, which have health consequences.
Shakoor Hajat is a private lecturer at the London School of Hygiene and Tropical Medicine and deals mainly with environmental epidemiology. © private
Zeit ONLINE: you have in your work intensively with the consequences of heat and cold on health. Especially for children, elderly and already weakened people is risky.
Hajat: That is correct. People need to get a core body temperature of approximately 37 degrees Celsius to maintain. You sweating or shivering therefore, the body sends more or less blood in the vessels to fingers and toes. All the strengt of the circulation. In susceptible people the not or sometimes does not work fast enough. This is true for people suffering from chronic diseases such as heart and lung diseases, and for children. And especially for the elderly. In ageing populations, there is therefore a higher risk for heat and cold dead, as well as for mortality from extreme weather events. Studies, the questions of how climate change affects the health, should take into account therefore it is imperative that as a society ages.
TIME ONLINE: For the UK you have tried to predict the effect of climate change on mortality. For Germany, unfortunately, there are no current studies. Your result: by 2050, the number of heat deaths more than tripled (Journal of Epidemiology and Community Health: Hajat et al., 2014). Where did you get such a number?
Hajat: First of all, I’ve been looking for data that show how many heat and cold deaths there are in the current temperature conditions. I have collected from the historical data, the daily number of deaths in the different regions of Britain and with the temperatures. This, in turn, epidemiological is – logically – a temperature-mortality function is calculated. In these functions I have used, instead of the current temperature from climate change projections for 2022, 2050 and 2080. The result is the predicted number of heat – and cold dead.
TIME ONLINE: And how accurate are such forecasts?
Hajat: The models are based on some assumptions: projections about how the temperature will change and, particularly, how the risk function changes as such. Due to demographic developments, for example, but also by measures of the countries, such as for example Heat alert systems. In the process, authorities send during particularly hot weather hints and tips were about on the phone. All in all, are a rather inexact science to say. Therefore, we give, for our estimates is also always a range.
TIME ONLINE: to what Extent, depends on the temperature, the health is detrimental, with the climate protection target of limiting global warming to 1.5 degrees?
Hajat Directly. But to understand how big the effect of this seemingly small temperature would change, helps e,s to look at the threshold values at which we see effects on mortality or hospital admissions. You can read threshold out of the data. It is located in London, for example, at 19 or 20 degrees. The moderately warm days cause the greatest burden of disease.