Sujets épreuve d'EURO pour le BAC, Lycée (Ocean Acidification, Global Warming, Jeans): Why is ocean acidification problematic ?

« Why is ocean acidification problematic? Introduction: Nowadays, the question of global warming and its consequences on the planet are increasingly raised.

This is particularly due to the fact that there are more and more natural phenomena caused by global warming that can be seen on our scale.

But what about phenomena that we do not see? Today I am going to talk to you about ocean acidification.

It is a consequence of global warming, and few people are aware of this phenomenon.

So I'm going to explain to you how it works. Questions: - What is global warming? Global warming is a global phenomenon of climate transformation characterized by a general increase in average temperatures (particularly linked to human activities), and which permanently modifies meteorological balances and ecosystems. - How are the oceans affected by global warming? A third of the C02 produced has always been absorbed by the oceans.

It regulates the carbon cycle which dissolves and reacts with other compounds present in the oceans.

You have to know that a solution is acidic when it is less than 7.

However, since the industrial revolution, much more C02 has been produced and the oceans must therefore absorb more and more of it.

It’s a real problem because the ocean pH decreased from 8.18 to 7.93. - How it works? C02 molecules are absorbed by the oceans and react with H20 to create H2CO3, which is carbonic acid.

However, with the increase in hydrogen ions due to the acidification of the oceans, this carbonic acid turns into bicarbonate instead of turning into carbonate.

Normally, calcium will unite with carbonate to form CaC03, useful for the formation of animal shells.

But there is less and less carbonate and more and more bicarbonate, and calcium cannot unite with bicarbonate.

Then, it’s impossible to create the CaCO3. - Why is it a problem? CaCO3 is necessary for marine ecosystems, which prevents animals from creating their shells (sea urchins, corals) which are the basis of the marine. »