Global warming will kill more than infectious diseases

Publicação: 8 de September de 2020

The world’s poorest and hottest regions are likely to suffer the most because they have the least resources available to invest, says researcher Dr. Amir Jina

Ghana and Sudan, for example, will be above average and will record 200 or more deaths per 100 thousand people. The richest and coldest countries, on the other hand, will suffer less, like Norway, where the number of deaths caused by the extreme cold should drop

Due to global warming, there is much concern about the future of the planet and the health of the population. A recent study published in the National Bureau of Economic Research, entitled “Valuing the Global Mortality Consequences of Climate Change Accounting for Adaptation Costs and Benefits” reveals that rising temperatures alone can kill more than all infectious diseases combined by the end of this century. According to the publication, global mortality rates will be increased by 73 deaths per 100 thousand people, roughly the same current number of deaths from all infectious diseases, including tuberculosis, AIDS, malaria, dengue and yellow fever.

To understand how high temperatures can lead to loss of life, Dr. Amir Jina, an environmental economist at the University of Chicago and co-author of the study, explains that some deaths appear with symptoms such as heat stroke – when the body overheats and the organs are damaged. According to him, deaths like these can be registered as related to heat when the people who died are examined. But probably a higher proportion of deaths occur in vulnerable populations or with pre-existing diseases. “An example of this are people with heart problems – as the body starts to work harder, pumping more blood, in an effort to cool down, it can trigger heart attacks or strokes. On examination, we can see this only as a heart attack, not as a heat-related death. Therefore, it is important to use statistics to attribute these deaths to the extreme heat that we might otherwise miss”, he points out.

Extreme climatic changes (heat and cold) can affect many aspects of health, from direct heat stress to aggravating conditions of the heart, lungs, kidneys or other important organs. These are the types of deaths that the researchers observed in the survey. There are other diseases that are known to be affected by climate change that can also lead to death, such as malaria and dengue, but the process by which heat affects these diseases has not been captured at work.

Even hotter tropics

While attention on global warming has turned to polar regions, the study warns that the countries most affected by the heat waves will be the tropical ones, which coincidentally are also the poorest. According to the survey, Ghana and Sudan, for example, will be above average and will record 200 or more deaths per 100 thousand people. The richest and coldest countries, on the other hand, will suffer less, like Norway, where the number of deaths caused by the extreme cold should drop

Professor Jina points out that this increased exposure to heat means two things: first, a warmer place is more likely to have people exposed to higher temperatures. Second, they can adapt better because they have already experienced warmer days, so they invest in fighting impacts. “Here difficulties arise for the poorest countries – adaptation costs money and the poorest countries have less resources available to invest. This means that the increase in high temperature exposure can’t easily be countered with expensive adaptations (like air conditioning, for example)”, points out the researcher.

Asked about the impacts that the Tropics should suffer, Dr. Jina comments that in a scenario of high emissions, just above where global emissions are now, there would be 73 extra deaths per 100.000 by 2100. He recalls that this is almost the same death rate from infectious diseases today. “If we were to reduce emissions to a level a bit more optimistic than the Paris Accord targets, this would drop to 10 per 100,000 by 2100” he adds. Mortality rates are higher in the Tropics (106 per 100.000) compared to the more temperate countries in northern Europe and North America, where there is a decline of -25 per 100.000 deaths. But this decline is the result of high spending on adaptation in the richest countries.

Regarding the types of resources that can be used to develop a network of diagnosis, modeling, analysis and intervention on the repercussions of these changes on health conditions, Dr. Jina says this is a very difficult issue. “Partly we need a focus on education of how to cope with extreme heat, where people learn how to limit activity outdoors, how to hydrate properly, and how to recognize when you need to seek help. we need to focus on health infrastructure – hospitals with the capacity to deal with surges in cases on hot days and the days after is an important factor here”, he argues. Still according to him, policy responses to extreme heat are also needed – companies need to determine breaks, cooling centers and other changes in the workplace. “The best thing we can do globally is to reduce our emissions to limit temperature changes”, he guarantees.

The economic cost of these deaths is also a factor to be considered. “We found that, in the high emissions scenario, the cost of deaths could be equivalent to about 3,2% of global GDP by 2100. A different way of thinking about this is the social cost of carbon due to changes in mortality, that is, the damage caused by the emission of a single extra ton of carbon dioxide today. We found it to be $ 36,60 dollars. And remember, that we are releasing billions of tons into the atmosphere each year”, says the environmental economist.

Reducing social vulnerabilities caused by climate

According to Dr. Jina, air conditioning is a fundamental defensive measure, but it is expensive and often depends on fossil fuel electricity, which would make the problem worse. “Some cheaper methods of staying cool for individuals may help, like cool roofs, but few of these have been tested at scale”, he acknowledges. The researcher also cites measures related to the health system and infrastructure: access to drinking water sources, a social safety net that helps people deal with health issues before they lead to negative consequences, hospitals capable of dealing with a surge of illnesses. Unfortunately, a reality that does not exist in many of the most affected places and that may never have access to these capabilities.

The process of global climate and environmental changes imposed on society and government sectors represents a challenge on the causes and the role of these environmental changes on health conditions. Apparently, the scenario arising from climate and environmental changes seems that it will remain surrounded by difficulties and coming up against great challenges.  Professor Jina admits that anticipating the future is a very difficult task and that they do not try to predict exact changes, but to obtain general scenarios and project them into the future. The climate change community has even built a set of scenarios for emissions (called “RCPs” or representative concentration routes) and socio-economic (called “SSPs” or shared socioeconomic pathways). “We project different combinations of emissions and socioeconomics into the future and arrive at a range of different outcomes, each of them depending on what global society chooses for climate policy”, he highlights.

Finally, the researcher reverberates that the countries that suffer the most are those that have done the least to cause climate change. “This inequality is an aspect of climate change that we need to remember whenever we debate climate policies”, concludes the study’s co-author.