COVID-19 is a major global shock that has upturned our lives, but how does it measure up in the grand billion-year scale of Earth history?
According to academics from the University of Leicester’s Centre for Palaeobiology Research, the pandemic won’t leave a direct record of COVID-19 for geologists of the far future to investigate, as viruses don’t fossilise. It may also be difficult to pick out a clear fossil record of victims too, as they could be difficult to distinguish among other causes of death. As they wrote in The Conversation:
There will be indirect signals such as some specific “technofossils” that are spiking in abundance. For instance, many billions of disposable face masks and gloves are already showing up in litter globally and working their way into the geological cycle. They are plastics-based, durable and so easily fossilised.
Their fossilisation can take different forms. Relatively intact gloves and masks may accumulate in riverbeds or at the bottom of lakes. Over time, they will be covered by more sediment and become fossilised in newly-formed rocks. Other masks and gloves will be carried into the oceans and some will be washed to distant shores, as the rise of PPE found during beach clean-ups is showing.
For our lifetimes, and many generations into the future, this will be a huge environmental problem that adds to the millions of kinds of technofossils we already produce. In the far future, it increases the chances of the events of 2020 being picked up in a fossil signal by some sharp-eyed palaeontologist.
Plastic pollution is up, but carbon emissions are currently down. This reduction might be seen in the fossil record of atmospheric carbon dioxide (CO2) in polar ice layers. But, so far this reduction is tiny. A decrease in other greenhouse gases such as nitrous oxide (N2O) might help to strengthen this fossil signal. The air has been cleaner, too, and so lake sediments may briefly include fewer fossil smoke particles.
All this evidence of slowdown will be subtle. If there’s an economic rebound, as the International Monetary Fund predicts, this will drown out any such evidence of the temporary reductions.
But the real geological effect will be if the pandemic acts as a catalyst to change society’s planetary impact, such as by decarbonising industry across the world. For former head of the UN climate convention Christiana Figueras, the recovery can be used to reshape industry and cut emissions. If sustainability policies are implemented then the faint, hopeful geological signals may shift from transient to permanent.
What would these signals look like, once petrified? If greenhouse gas emissions continue to reduce through climate-friendly policies, climate stabilisation would be recorded not just in ice and lake cores but in corals, tree rings and stalagmites worldwide. Investing in ecosystem resilience and restoration projects would be economically beneficial, and also increase the diversity of plants and animals whose bones, shells and pollen end up in sediment layers. Developing the circular economy in response to this economic recession could slow, and eventually halt, the flood of single-use plastic waste, too.
The acid test of that will be in the rock strata that will form from now on – either they will show signs that the accelerating trends of the current geological age carried on, or they will show a deflection away from a potential “Hothouse Earth” and towards some kind of new stability.
The future is not yet set in stone, but in the very long run the rocks will tell the story of which road we collectively take.
This is an abridged version of an article originally published in The Conversation. Visit theconversation.com/what-will-covid-19-look-like-to-geologists-in-the-far-future-143085