Glaciers: The hidden source of pandemics?

We all need to remain vigilant of the increasing pace of glacier melting and the consequent biological disasters it could unleash, writes Dr AM Deshmukh

As communities across the world are slowly picking up the pace, reacquiring a semblance of pre-COVID normalcy; as successful vaccine trials mark a decisive turning point against our fight against coronavirus, the world is starting to truly appreciate the need for preparedness to avoid such colossal disasters in the future. One such likelihood we have to remain vigilant of is the increasing pace of glacier melting and the consequent biological disasters it could unleash.

The melting and shrinking of glaciers is not news. We also know its prominent cause: global climate change. There is a widespread scientific consensus that human activity is the leading cause of climate change. Despite knowing its immense environmental costs, we continue to burn fossil fuels and convert land from forests for agricultural purposes. These activities release an enormous amount of carbon dioxide — a greenhouse gas — in the atmosphere. Greenhouse gases also come from other human activities, including the combustion of fossil fuels in cars, buildings, factories, and power plants. Particularly over the past few decades, we have seen the enormous consequences of such global warming: increased forest fires, unpredictable and extreme seasonal changes, unusually harsh winters and unbearable summers. Global warming also leads to the melting of glaciers from across the world. This, as we will see, is a worrying development for many reasons. 

Climate change

A glacier is a large mass of dense ice that is spread across a large area of land and moves slowly under its weight. Apart from polar regions, glaciers occur mainly in high mountainous regions such as the Himalayas, the Andes, and a few high mountains in East Africa, Mexico, New Guinea, among others. Notably, outside polar regions. Overall, glaciers cover about 10 per cent of Earth’s land surface and contain approximately 75 per cent of the world’s fresh water in a frozen state.

Worryingly, researchers believe that most central and eastern Himalayan glaciers will be released from mountains and will disappear by 2035. Arctic sea ice has also thinned substantially over the past half-century. This melting effect has played a significant role in raising average global sea level between 10 to 20 centimetres in the past hundred years, according to the Intergovernmental Panel on Climate Change (IPCC). What is equally concerning is that the current rate of global sea-level rise has deviated from the average rate over the past two to three millennia and is rising more swiftly — about one-tenth of an inch every year. This has an added effect on the release of glaciers from colder regions of the Earth.

Glaciers and hidden microbes

With the melting of glacier ice, the world faces an ever-increasing possibility of the release of ancient viruses and bacteria buried deep within the frozen mass. This is a big challenge. Throughout history, humans have co-existed with a variety of bacteria and viruses. We have evolved to resist many pathogenic viruses, bacteria and fungi via immunity, medicines, or vaccines. Nevertheless, these microorganisms continue developing new ways of infecting us. Adding to this trend is an additional possibility of sudden exposure to deadly viruses and bacteria arising out of human engagement with previously unexplored habitats. The most recent and prominent example is the current coronavirus pandemic. The virus was present only in forest regions and was infecting only birds and animals. The sudden entry of this virus in the human world has caused a great disaster, almost entirely freezing all human activity.

A similar potentiality remains concealed under the vast swathes of glacial ice. People, as well as plants and animals of different kinds from pre-historic times to this day, have been buried in the frozen glacial frozen for centuries. Evidence supports the hypothesis that infectious bacteria or viruses are also buried with their remains. For instance, in the bodies buried in Alaska’s tundra region, scientists have found remnants of RNA from the 1918 Spanish flu virus. Many scientists believe that smallpox and bubonic plague pathogens are also likely buried in the Siberian ice. In 2015, scientists discovered dozens of unseen virus groups from northwestern Tibetian Plateau.

Similarly, NASA scientists recently managed to isolated bacteria encased in a frozen pond in Alaska for over 30000 years. The microorganisms, called Carnobacterium pleistocenium, remained frozen since the period when woolly mammoths still walked the Earth. Once the ice melted, the bacteria “came back to life”, swimming around, seemingly unaffected. Scientists have been able to confirm similar revivals of ancient microorganisms through further experiments. Scientists have also noted a heightened risk of the revival of the Anthrax bacteria because they form spores, which are extremely strong and can remain frozen for more than a century. This apprehension came true in 2016 when a young boy and over two thousand reindeers died due to anthrax bacteria, unleashed via defrosting of a reindeer carcass from over seventy years back. The reindeer was a victim of an anthrax outbreak from 1940’s. One shudders to imagine the havoc similar large-scale outbreaks would cause.

What is becoming increasingly clear is that glacial ice appears to be an active reservoir for pathogenic microbes, many of them yet unknown to modern science. As a result of permafrost melting, these microbes may come outside in the environment and deadly infections of the past two centuries may re-enter human population, mainly from near the graves where the victims of these epidemics remain buried.

The road ahead

Coronavirus has taught us an important lesson — that we cannot afford to be indifferent to such situations anymore. We must proactively try to prevent the retreat and melting of glaciers due to climate change. We must sensitize people about this issue to generate large scale social movement and co-operation that would reduce the emission of carbon dioxide in the climate. We must press our governments for more environmentally conscious policy choices. We must consciously minimize our climate change accelerating activities. A few concrete steps we can take in that regard would be:

  1. Using public transportation or eco-friendly modes of transport: Millions of cars emit tonnes of greenhouse gases every minute. It is one of the leading causes of climate change today. Travelling by public transportation for work or other activities is a great way to reduce CO2 emissions. Riding your bike to work does not only keep you healthy but is also a constructive way to sustain the environment.
  2. We all should try to cut down on daily energy usage in our households. These invovle simple things such as turning off lights or unplugging devices when not in use. These small acts, when considered cumulatively, make a huge difference.
  3. Manufacturing factories release a massive amount of greenhouse gasses every year. Recycling of goods is a cost-effective and environment-friendly method that reduces the production of goods, consequently reducing their co-hazardous manufacturing practices
  4. Lastly, but perhaps most importantly, we must educate the general public about the causes and prevention of
    climate change.

Unless we realize the urgency of this challenge before us and unless this carries a momentum that substantially alters our unsustainable economic attitudes and lifestyles, we may be looking at an endless cycle of new pandemics like the current one. A possibility I am sure most of us would like to avoid at any cost.

Dr AM Deshmukh is President, Microbiologist Society, India. Views expressed are his own