3 Critical Ways in Which Climate Change Impacts Pandemics
According to recent scientific research, Covid-19 isn't going to be the only pandemic this decade, much less this century. Climate change is at the center of the forces disrupting the nature of pandemics in our world.
According to a study analyzing global trends in emerging infectious diseases, published in the journal Nature, there has been a considerable increase in the number of infectious diseases between 1940 and 2008. Most of the pathogens causing these diseases are coming from animals. Unfortunately, this increase is directly related to the broader changes happening in our climate.
In the 1940s, there were a little over 20 emerging infectious disease outbreaks reported around the world. By the 2000s, this number had grown closer to 80. That is an increase of nearly 4 times.
There are three main links between climate change and infectious diseases.
Merging of Habitats
Nearly 60% of new pathogens come from animals. These microbes have existed in our ecosystem since there has been life on this planet. However, earlier, they were geographically distant from us. There was a significant distance between the home of a human and that of a wild bat. With changing land-use patterns, these are moving dangerously close. As a result, these microbes are able to jump from animals to humans more easily than ever. Biologically, we do not have the defense mechanisms against most viruses, which makes us highly prone to newer and deadlier infections.
Consider the case of the 1998 Nipah outbreak in Malaysia, the real-life event that was adapted for the film Contagion. The problem began with rapid deforestation in the area, which then led to the shrinking of the forest habitat of bats. As a result, large colonies of bats moved closer to human settlements. Bats would feed on orchard fruits and drop half-eaten fruit on the ground, where it was eaten by pigs in the surrounding pig farms. The slaughtering of these pigs for meat led to the outbreak of a virus that eventually killed more than 100 people. As the climate degrades, such events, with potentially more infectious and deadlier viruses, could become a routine occurrence.
Increase in Vectors
The second big reason for the rise in infectious diseases is the increase in the geographical habitat and population of vectors (mosquitoes, rats, fleas, etc.) that carry them. With the planet becoming warmer, a number of rodents that earlier survived only in the tropics are now able to survive and spread disease over larger areas. The Nature study quoted above also found that nearly one-third of the diseases originating in the last ten years were vector-borne, and their jumps into the human population coincided with unusual changes in the climate.
Another study, published in the journal PLOS Neglected Tropical Diseases, predicts that by 2050 these vectors will reach over 500 million more people in newer geographies. In fact, early trends are here already. In 2013, New York reported its first-ever case of locally transmitted Dengue fever, a viral infection common to the tropics but unheard of in America.
Today, large mammal populations are suffering a decline at the hands of hunters and loggers. However, smaller animals such as bats, rats, and other rodents are thriving, either because they are more resilient to the changing environment or because they are adept at hiding their presence from humans. With them thriving, the health of the human population is at risk. A warmer climate, more precipitation, and the loss of predators will further boost their numbers and, with that, the risk of infectious diseases.
The 1999 Hantavirus Pulmonary Syndrome (HPS) outbreak in Panama is a typical example of this. In that year, the country’s Los Santos province experienced nearly three times more rainfall than usual. This caused a substantial increase in the region’s rodent population, which eventually led to an outbreak of HPS, a life-threatening respiratory disease.
Melting Ice
Lastly, climate change is increasing the rate of melting ice in the northern hemisphere. This is particularly worrisome from the case of the permafrost in the north. Melting ice will uncover a number of dead animals that died due to a now extinct or dormant virus or bacteria. As these corpses are revealed, those sleeping pathogens could strike again.
According to an article by BBC, in 2016, this is exactly what happened with the heatwave of 2016 — the northern permafrost melted to release infectious anthrax into the soil and water. This ultimately led to the death of a 12-year-old boy and led to the hospitalization of at least 20 other people.
One cannot even begin to contemplate the dangers we could face from these dormant viruses.
Covid-19, with a mortality rate of below 2%, has brought the entire world to a halt. It has dictated all our actions over the last year and a half. Even today, the end of this battle seems nowhere in sight. And yet, we are ultimately not learning our lesson. We are ultimately still playing with forces of nature that we cannot control. Ultimately, we are still living in a fool’s paradise.
The only solution today is to tackle the problem of climate change head-on. It is the only way to create a safe condition for human life to prosper in the 21st century.
In our fight against Covid, we have to remember; this is only a battle. The war is much longer and much harder.
