[ad_1]
Humans could be the most egregious example of how life can wreak havoc on the natural environment of a planet, but life of all kinds drives the climate of the planet. world in new directions over time. The evolution of the first animals on Earth, in fact, helped spur climate change nearly half a billion years ago, according to new findings published in Nature Communications
. The evolution of the first burrowing marine animals about 520 to 540 million years ago, during the Cambrian era, was followed by a significant reduction of oxygen in the oceans of the planet. One theory that has begun to circumnavigate is that burrowing behavior has broken down organic matter in the seafloor and released carbon dioxide stored in the waters. This carbon dioxide gradually entered the atmosphere and led to a slow warming period of 100 million years in the Paleozoic.
However, "the idea was not fully taken into account that these first animals only sank in the depths, maybe a centimeter lower, so we thought that they had only a minimal impact compared to animals that evolved much later and buried much deeper, "says Benjamin Mills, a University researcher. from Leeds, UK, and co-author of the new study.
Mills and his team decided that it was time to really put this theory to the test.Try to understand what Earth looked like in the Paleozoic era is not as difficult as in the past, thanks to the advent of computer modeling.After plugging known data and performed several simulations, the team found that the scenario that best corresponded to the geological and climatic data of the Ter re was the one in which the first ocean burrows significantly changed the geochemistry of sediments in the oceans. Mills
The team knew that these discoveries were a possibility, but had not thought as much about the potency of organic matter oxidation as contributing to atmospheric carbon dioxide. The team found that the evolution of the first animals on the planet was sufficient to pump in the air about 1,000 parts per million of carbon dioxide, which warmed the planet by 5 degrees Celsius
. can tell us something about how our current world deals with human-induced climate change. "There is a parallel with the current burning of fossil fuels," says Mills. "Essentially, we are doing the same thing as these early animals by oxidizing organic matter on a global scale.However, the Cambrian events have occurred over millions of years, and still seem to have made life difficult for the biosphere of the time humans recreate this event but on a much shorter time scale, which leaves much less time for climate feedback stabilization systems. "
In other words, the Earth is resilient enough to adapt to changes in atmospheric chemistry, but only if these changes are made slowly . Humans pollute the atmosphere too quickly with too much carbon dioxide, and the result is of course a devastating environmental domino that falls one after the other.
But at the very least, the new discoveries are a step forward to help scientists. better predict what will come next, and arm them with evidence that policymakers can use to push for more regulation of greenhouse gas emissions. "The history of the Earth is still very poorly understood, particularly the processes that have kept the planet's temperature roughly steady for billions of years," Mills explains. "Our Earth system model allows us to recreate past climate events while producing many lines of independent geological data, allowing us to test hypotheses and eliminate those that do not fit"
[ad_2]
Source link
