It is well understood that COVID-19 is a health crisis. COVID-19 is a zoonotic disease, meaning that the virus is transmitted from animals to humans. Other examples of recent zoonotic disease outbreaks include the Zika virus, SARS (Severe Acute Respiratory Syndrome), Ebola, West Nile Virus, Avian Influenza (bird flu), and numerous others. In 2016, the United Nations Environment Programme declared zoonoses as a global issue after studies have shown that new infectious diseases are occurring among humans on an average of three times per year.
But why are zoonotic diseases occurring more frequently?
The cause of COVID-19 is more than just a health crisis. In fact, the issue strongly correlates to the ecosystem crisis. COVID-19 originates from the animal world. Since the genesis of animal domestication, we have rapidly maximized our interactions with the animal world. For example, Inger Andersen states that “we have greatly maximized animal farming, which as increased by over 200% since the last thirty years of domesticating animals. We have also increased our appetite for cutting down tropical forests and animal homes to expand into these lands for our benefit”. By increasing our interactions with natural habitats, we are enabling pathogens from these natural habitats to spread into the habitats of humans and livestock.
Specifically, here are two human activities that contribute towards the increase in zoonotic diseases:
Greenhouse gas emissions
Burning fossil fuels can impact the survival of microbes due to changes in temperature and humidity. Rapid changes in weather hinder ecosystems’ abilities to balance the population of different species. Therefore, vectors for diseases, such as mosquitoes, increase in population size. There is no doubt that as the climate continues to change, zoonotic diseases will occur more frequently and generate more damaging health effects.
With higher demands for dairy and meat products, livestock farming has increased in popularity. This increase has led to the expansion of land for farming, which has bridged together the animal world and the human population. This bridge also facilitates the transfer of viruses and pathogens from animals to humans, posing a higher risk for zoonotic diseases.
Additionally, to improve the productivity of livestock farming, many farmers have taken advantage of intensive farming, utilizing higher amounts of pesticides for crops and medication for animal stocks. Gradually, the practice of intensive farming allows pathogens to build their resistance to medications, especially those for zoonotic diseases.
On the bright side, there are several activities we can do to prevent the emergence of future zoonotic diseases:
Greater ecosystem diversity hinders the ability of pathogens to rapidly spread from animals to humans. A study in 2012 confirmed that pathogens were more likely to build resistance in fields growing the same crop. The lack of diversity in crops provided this opportunity to the pathogens. Likewise, with less biodiversity in the animal world, viruses and diseases are more likely to spread and gain resistance to disease medications.
Slow down climate change
Climate change is capable of drastically changing our lives, through changes in weather patterns, temperature, and more. Climate change also plays a large role in the emergence of zoonotic diseases. Therefore, we can live more sustainable and eco-friendly lives, reduce the amount of waste we produce, and educate ourselves on climate change and its repercussions to make a large impact on our planet.
Unfortunately, there are thousands of zoonotic diseases among us that are soon to emerge. We are the only ones who can prevent further outbreaks of perilous diseases, but to do so, we must also understand the deeper roots of these outbreaks.