Climate Change and Extinction – Adaptation or Extinction

Life is being redistributed under the water’s surface. As the world’s oceans warm, fish, plankton, and even corals are trying to move toward the poles – that is, where conditions are cooler. Unlike the inhabitants of the land, the organisms of the sea react more directly to changes in temperature. And they can do it too: the oceans give them space to swim away or let themselves go away.

The situation on Earth is different, with mountains, rivers, settlements, arable land and roads blocking the path of species. On average, marine organisms travel 72 kilometers per decade toward the poles, but Earth’s inhabitants are only 17 kilometers per decade.

That’s why biologists have so far assumed that fish, crustaceans, and marine mammals are perfectly capable of escaping climate change. However, this only appliesAnd As long as there is a climate on Earth-nMarine organisms are only displaced, but not completely lost or completely new climatic conditions arise to which animals and plants are no longer adapted. But that’s exactly what’s threatening, as ecologists and land scientists working with Katie Lauterhus of the Center for Marine Research at Northeastern University in Nah.aNT in Massachusetts, USA in Scientific Reports.

Completely new climatic conditions are likely to lead to massive selection, acceleration of evolution and the elimination of many species.

Using climate simulations, they show that warming and, above all, acidification over the course of the century can create new climate conditions over large parts of the sea surface that have not existed in the world for the past 200 years. If the Earth continues to warm as before, new climate conditions could develop on more than 80 percent of sea surface by the end of the century, in the case of the somewhat milder scenario where the temperature rises by 2.6 degrees to more than ten in cent. . “So it makes a huge difference whether we warm the world by 2.6 degrees or 4.8 degrees,” says Lauterhus.

At the same time, climatic conditions that are currently still present in parts of the world’s oceans are likely to disappear in the future, depending on the scenario for about 36 to 95 percent of sea surface. Both scenarios would represent the lower and upper bounds of the current emissions trend fairly realistically. Lauterhouse compares this to moving: “If the familiar climate disappears, that means our home disappears and we have nowhere to go,” she says. “But if there is a new climate, it means: we have to go to a new place where we have not been before, and the weather there is completely different.”

At the turn of the century, large parts of the upper ocean layers could enjoy climatic conditions that many species could no longer tolerate. Avoiding heat and a more acidic environment would then not be an option as there is no way out. The alternative would be: adaptation or extinction.

So if the world continues to warm as before, the oceans will not be recognizable in a few decades. The entirely new climatic conditions are likely to lead to massive selection, accelerating evolution and eliminating many species, according to the authors. The species community in the upper layers of the sea will be completely re-formed, and it will be with more ‘uUnpredictable Environmental surprises are expected.

“Most people have an extreme idea: either everything dies or all of life will somehow find a way out.”

Katie Lauterhaus, marine scientist

First and foremost, the Indo-Pacific region, one of the most biodiverse regions in the world, is likely to be affected. Especially in the waters around Indonesia, new extreme weather conditions could prevail by the end of the century, or old weather conditions and corals could disappear. can with her To be among the first victims of climate change.

But the authors cannot say what will actually happen to marine life when new climatic conditions appear or old ones disappear. Some species may be able to tolerate or adapt to unknown conditions to a certain extent, as shown in experiments with phytoplankton exposed to high concentrations of carbon dioxide. aBut it does exist first Some examples of climate change adaptation, according to Lotterhos.

“Most people have an extreme idea: Either everything will die or all life will somehow find a way out,” says Sea Scientist. But the answer is very likely somewhere in the middle.» However, this event can still be avoided – by limiting global warming to less than 2 degrees. According to the researchers’ models, this would prevent an entirely new marine climate. “As a scientist, this phenomenon will of course be an interesting topic for study,” says Katie Lotterhaus. “However, I would prefer not to have to observe what happens in such a situation.”

Publication date: 08/31/2021, 7:15 pm

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