Climate change has been devouring several species of plants and animals all across the planet. As per the United Nations, in the upcoming decades, we might have to lose 1 million species of plants and animals if we continue to heat our planet. Even the hardiest among all the creatures — Tardigrades — have been found to have weakness under long exposure of high temperatures and when the climate change becomes extreme, they too will struggle to endure it. This goes on to show that even the species once considered indestructible will find it difficult to adapt to global warming and climate change.
Tardigrades — adorably known as water bears or moss piglets — have been the poster species of resilience since time immemorial. Mostly found in wet environments, they can be located in marine as well as freshwater sediments. Having survived the five mass extinctions on earth, these tiny creatures — which are between 0.3 and 0.55 mm in length — can endure the extreme conditions; whether it is highs and lows in temperature and pressure or unavailability of food for years, these microscopic organisms can survive it all — even the vacuum of space, zero oxygen or high cosmic radiation. They get this “supernatural” power by their ability to dry out, reconfigure their bodies and enter a state of suspended animation or a ‘tun’ state — a process known as desiccation which can be induced by extreme conditions such as lack of water around them. Owing to their ‘unkillable’ attribute because of the presence of protective genes, tardigrades have been the subject of several studies by scientists all over the globe which might, in future, open the doors of ‘immortality’ for human beings!
Recent studies, however, present enough pieces of evidence which might strip Tardigrades off of their label of being indestructible. Their death-defying skills may no longer work in the face of extreme changes in the climate which have been driven by human activities such as the burning of fossil fuels including coal, crude oil and natural gas. One of their 1300 known species, Ramazzotius varieornatus, has been found to be vulnerable to long exposure of high temperature which is expected to become more common in the decades to come. Well-hydrated Tardigrades in normal conditions, when exposed to high temperature, have been found to be dead even in a slight uptick in temperature. The ones which were pre desiccated before being exposed to rising temperature could endure a higher degree of temperature.
With climate change expected to get worse in coming decades, the frequency of heatwaves and drought would increase dramatically which would have a negative impact on many organisms, including Tardigrades, thus increasing their mortality rate. This increased mortality rate of Tardigrades, in turn, could have a ripple effect over the entire ecosystem where they live. This fact highlights the severity of climate change and how even the toughest creatures on the planet would find it difficult to cope up with the implications of human-induced climate change; and, unless we take radical steps to curb greenhouse gases emissions, we may have to brace ourselves for a catastrophic future!