Climate: we have reached the point of no return of climate change

According to a blog post published by the Scripps Institute of Oceanography, “everything leads us to believe that this value will not fall, either before the end of the year, or … ever. This prediction is based on weekly monitoring of CO2 levels at the Mauna Loa Observatory in Hawaii, made with the greatest attention since 1958.

Why is this number so serious?

Several years ago, scientists and researchers warned us that if the carbon concentration in the atmosphere were to exceed 400 ppm, it would be a turning point in the history of our climate since we would have reached a threshold effect that would to bring us into a dark period: global warming would become completely irreversible.

In 2012, the Arctic was the first region in the world to overtake this red line. Three years later, for the first time, the carbon concentration in the atmosphere remained above 400 ppm every day for a month.

Climate

Graphique: National Oceanic and Atmospheric Administration . Description du site web de Scripps CO2 Program, « Keeling Curve Lessons. »

This time, experts believe that carbon concentration levels will not be able to decrease. This statement is due to the cyclical nature of the evolution of the CO2 concentration observed at Mauna Loa; every year, CO2 levels are usually at their lowest in the month of September. This year, the lowest point on the curve is 401 ppm. There is a probability that we have not yet reached the lowest CO2 levels for the year 2016, but according to scientists, this probability is really low.

This alarming announcement could have a virtuous effect: terrifying populations, and perhaps raising awareness, that would push governments to take immediate and reliable action. The Paris Agreement, the first universal agreement dedicated to the fight against climate change and its effects, set out firm objectives directly inspired by these sad observations.

Each country that signed the agreement is required to help maintain global average temperatures below a critical level of 1.5 ° C above pre-industrial averages. To achieve this, it will be necessary to limit carbon emissions and enforce ambitious targets on so-called clean energy. However, the 60 countries that have ratified the agreement produce only 47.76% of global carbon emissions.

Knowing this, we can deduce that climate change will have permanent effects that are quite catastrophic:

Mass extinction

Although it is particularly difficult to estimate, the extinction rate is 1000 times faster today than it was before the appearance of modern Homo sapiens. WWF estimates that an additional 10,000 species die each year. As a result of climate change, a quarter of all living species could disappear by 2050, or one in four.

Food chain : the break

Closely linked to the extinction of species, food chains are likely to be permanently out of balance as large predators and their prey disappear. In the Arctic, for example, rising ocean temperatures have an impact on the development of marine algae, which in turn deprives zooplankton, cod, seal and polar bear populations of essential nutrients. Over the last fifty years, average temperatures in Alaska and western Canada have increased by nearly 7 ° C.

The rise in the level of the seas and oceans

In the very near future, humans, among other species, will be affected by sea level rise in a catastrophic way. As the old glaciers melt, the design of the shoreline will be changed, the ocean will take possession of the land, and the communities will be forced to move. By 2100, 13 million people will leave their homes at sea. In some parts of the world, as in the Pacific Ocean, for example, this phenomenon has already begun. Scientists believe that even if we stop rising temperatures, this phenomenon is irreversible.

Ocean acidification

Considered one of the best indicators of the health of our environment, the acidity of the oceans has already wiped out the map of whole marine ecosystems. The oceans of the planet permanently absorb excess CO2 from our atmosphere, which lowers their pH and acidifies the water. As a result, vast expanses of essential coral in our ecosystems, such as the Great Barrier Reef, in Australia, are on the brink of death. Although coral polyps may still take root and push back into the reefs, scientists predict that their destruction will leave lasting traces on ocean ecosystems.

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