Why Are We Seeing More Pandemics? Our Impact on the Planet Has a Lot to Do With It

Pandemics – the global spread of infectious diseases – seem to be making a comeback. In the Middle Ages we had the Black Death (plague) and after World War I we had the Spanish flu. Tens of millions of people died from these diseases.

Then the learning began gain an advantagewith vaccinations having eliminated smallpox and polio almost as much. Antibiotics became available to treat bacterial infections, and more recently, antiviral drugs.

But in recent years and decades, pandemics they seem to be coming backIn the 1980s we had HIV/AIDS, then several influenza pandemics, SARS, and now COVID (no, COVID is not over).

Why is this happening and is there anything we can do to prevent future pandemics?

Unbalanced ecosystems

Fit, stable ecosystems provide services that keep us robust, such as providing food and neat water, producing oxygen, and giving us green spaces. recreation and well-being.

Another key ecosystem service is disease regulation. When nature is in balance—with predators controlling herbivores and herbivores controlling plant growth—it’s harder for pathogens to emerge in ways that cause pandemics.

But when human activity disturb and disrupt the balance of ecosystems – for example as a result of climate change and loss of biodiversity – things are going wrong.

For example, climate change is affecting the numbers and distribution of plants and animals. Disease-carrying mosquitoes may move from the tropics to once-temperate climates as the planet warms, and they may infect more people during months that are normally disease-free.

We investigated the relationship between weather and dengue fever transmission in China and our findings support the same conclusion they reached many other studies:Climate change is likely to put more people at risk of dengue fever.

Loss of biodiversity can have similar effects by disrupting food chains. When farmers cut down forests in South America In the first half of the 20th century, in order to provide food for cattle, the tiny, forest-dwelling, blood-sucking vampire bats suddenly had a wide choice of immense, sedentary animals on which to feed.

Although the vampire bat population has so far been sustained by confined food availability and the presence of predators in a balanced environment, forest ecosystemThe population of this species in South America has increased dramatically.

These bats carry the rabies virus which causes fatal brain infections in people who have been bitten. Although the number of deaths from bat-borne rabies has fallen dramatically thanks to vaccination programs in South America, rabies from bites from other animals still occurs is a global threat.

As urban and agricultural development impacts natural ecosystems, the risk of humans and pets being infected with pathogens that are normally found only in wild animals increases – especially when humans hunt and eat wild animals.

For example, the HIV virus first human populations from monkeys killed for meat in Africa and then spread around the world through travel and trade.

Meanwhile, it is believed that bats original tank for the virus that caused the COVID pandemic that has killed more than 7 million people so far.

Ultimately, until we effectively address the unsustainable impact we are having on our planet, pandemics will continue to recur.

Targeting the root causes

Factors such as climate change, biodiversity loss, and other global challenges are the ultimate (high-level) cause of the pandemic. Meanwhile, increased contact between humans, pets, and wild animals is the direct (proximate) cause.

In the case of HIV, although the proximate cause was direct contact with infected monkey blood, the monkeys were killed solely because immense numbers of very needy people were starving – which was the root cause.

The difference between final causes and immediate causes is crucial because we often only deal with the proximate causes. For example, people may smoke because of stress or social pressure (ultimate causes of lung cancer), but it is the toxins in smoke that cause the cancer (proximate cause).

Generally speaking, the health service is only interested in stopping people from smoking – and treating the diseases that result from it – rather than removing the factors that lead people to smoke in the first place.

Similarly, we approach the pandemic with lockdowns, masks, social distancing, and vaccinations—all measures that are designed to stop the spread of the virus. But we have paid less attention to addressing the ultimate causes of the pandemic—perhaps until recently.

Approaching Planetary Health

There is increasing awareness of the importance of adopting a “planetary health” approach to improving human health. concept is based on the belief that human health and human civilization depend on the flourishing of natural systems and the wise management of those systems.

This approach will prioritize key drivers such as climate change and biodiversity loss to prevent future pandemics, while experts from many different fields will work together to tackle the immediate causes, reducing the overall risk.

The planetary health approach has the advantage of improving both environmental and human health simultaneously. We are pleased with the increased interest in teaching planetary health concepts in environmental sciences, humanities, and health sciences at many universities.

With the risk of disease outbreaks continuing to escalate due to climate change, biodiversity loss, population displacement, travel and trade, it is critical that the planet’s future stewards better understand how to address the root causes that trigger pandemics.

This article is the first in a series on the next pandemic.