Let me tell you a story based on facts published some years ago. Specifically on new findings about the biology of plesiosaursin calculations on rates of species extinction and in some advances on ecological aspects of global phenomena such as the one that occurred a few years ago. 200 million yearsThe moment in which we place our protagonist.

Kansas would swim around enjoying the sun and the coolness of the water. Occasionally, she would dive after a school of fish and return to the surface to warm up and keep an eye on the young. She was a really big plesiosaur, weighing several tons and the oldest of the herd. She enjoyed a relatively quiet life, typical of one who knows she is at the top of the food web. Just as her parents had done with her, Kansas had taught her offspring where to find the best prey, to protect themselves from storms and to be wary of some neighbors. The world, apparently unchanging, was going on without surprises or great novelties. However, he had the feeling that the sea no longer tasted like it used to and that nowadays the prey seemed smaller and scarcer. The teenagers looked at him with disdain when he talked about such things. And maybe they were right. Maybe it was her perspective on the world that had changed. After all, she, too, remembered how exaggerated her grandmother seemed to her.

Our protagonists could hardly know the dramatic processes that had begun thousands of years ago, altering the chemistry of oceans and atmosphere while radically modifying the shape of the emerged lands. Pangaea, the great supercontinent, was beginning to fragment, giving way to the Jurassic era in which dinosaurs would dominate the Earth. Once again, the Earth's crust set to work to reshape the face of our planet. Billions of tons of sulfur oxides, carbon and other gases were added to the atmosphere, radically influencing the global climate. Temperatures rose, causing methane deposits to melt, which in turn fueled global warming. New seas opened up and immense territories went under water while others emerged to receive the light of a sun they remembered as much younger. Too many changes to go unnoticed by the biosphere. The fossil record tells us that about 80% of the species disappeared in this time period. Kansas could not have known it, but it was experiencing the Triassic-Jurassic (TJ) extinction first hand.

Such catastrophic events are known as mass extinctions. There is nothing biologically exceptional about species going extinct; it happens all the time. However, during mass extinction events the number of extinctions is extraordinarily large (typically considered to be losses of more than 75% of known diversity) and rapid. To date, five major events have been identified in which the magnitude and speed of extinction abruptly break the scale: three prior to the TJ (in the Ordovician, Devonian and Permian) and another 135 million years later, in the Cretaceous to Tertiary transition (KT), which wiped out virtually all dinosaurs.

But catastrophic, abrupt and rapid are adjectives that evoke an image that is out of touch with reality. We are talking about planetary-scale phenomena involving unimaginable amounts of energy. The dimensions of time and space are so large that even geological moments labeled as drastic changes can span hundreds of thousands or millions of years. It is very difficult to determine how long a mass extinction event lasts, but estimates always speak of several million years (except perhaps in the case of the KT, where the meteorite collision may have caused an impact on decadal or smaller scales). In addition, recorded extinctions in the oceans and on land may be millions of years out of date due to complex chain effects within the biosphere's network of interactions.

Since mankind has begun to exert a significant effect on ecosystems (let's say about 10,000 years ago), many species have disappeared directly or indirectly because of us. The figures for the best known groups (such as mammals, birds or amphibians) suggest that we are far from 75%, but in some groups the percentages of species threatened with extinction (species that are likely to disappear in the near future) are close to 50%. With respect to speed, there is no doubt. The current rate of extinction would lead us, in an equivalent geological time, to an impact on Biodiversity comparable to that of the previous big five. We are, like Kansas, witnessing a major mass extinction event.

The TJ extinction lasted several million years and did not noticeably affect plesiosaurs but did affect the diversity of several groups of gastropod mollusks, cephalopods and bivalves, marine sponges and some dominant groups of terrestrial tetrapods such as the thecodonts. Having enjoyed the wonders of the ocean all her life, Kansas could never have imagined being in the midst of one of the greatest extinction events in Earth's history. Like her, we may be experiencing the effects of a major extinction in progress, but not realize it because we are short-sighted. In science, being myopic is equivalent to not having enough information. We need to know more, to have more time series data to address key ecological questions to understand what is happening to Biodiversity. The impact we have caused on the biosphere is on the way to being equivalent to that of the events that triggered the great extinctions of our planet. This time we are not dealing with an asteroid impact, a global geological phenomenon or uncontrollable astronomical circumstances. The current biodiversity crisis lies in our way of interacting with nature. The sooner we address the issue of resource exploitation, resource sharing and waste management, the sooner we will slow down the current rate of extinction.

This article was originally published in The Conversation. Read the original.