Coral bleaching and ocean acidification

Global warming alarmists make much of how there are greater expanses of corals bleaching and the oceans are becoming more acidic. Besides the fact that man is not causing the Earth to warm by CO2 emissions, it could be that there is nothing to worry about in these two events. One is a survival mechanism and the other is self limiting. 

coral collage

 

Firstly, corals are meant to bleach. Corals get their colour from algae which live on them. Whenever there is a change in the local environment, one set of species of algae ups and leaves and a new set of species of algae which like the new environmental conditions soon takes its place. The period in between the different species of algae taking up residence is what makes the corals look white – coral bleaching.

 

This is a very strong adaptation mechanism and explains in part why corals have been around for so long even though the world climate has changed many times over the millennia.

 

Secondly, the oceans have become a little more acidic over the past few hundred or more years due to an increase in CO2 in the atmosphere. The ocean water absorbs a bit of the gases over the top of them. This is one of the ways that oxygen gets in the water so that fish can “breath”. If there is more or less of a certain gas in the air, more or less of that gas will be absorbed by the oceans.

 

However, there is a limit to how much of any gas can be absorbed by the oceans. When water is warmed, you can dissolve a greater concentration of solids in it. Try it with a cold glass of water and a warm glass of water and either sugar or salt.

 

The opposite happens with gases. When the water is cooler it can absorb more gas than when it is warmer. The reason for this opposite effect is due to the physical properties which make a substance a gas, a liquid or a solid – at a certain temperature. If the surrounding temperature drops hugely, CO2 will freeze into ice. At some temperature in between it will become a liquid. On the other hand even metal or rock will become liquid if you apply enough heat.

 

As you heat a liquid, it releases more of the gas that is absorbed in it. This explains why warm Coke or beer goes “flat”.

 

Therefore, there is a limit to how much CO2 can be absorbed in the oceans. It is possible that the oceans are at or close to the level of CO2 they can absorb at the current level of global temperature. If the Earth’s temperature rises a little more, it will be able to absorb less. Therefore the CO2 will stay in the atmosphere, rather than being dissolved in the water of the oceans.

 

This then means there will be a lid on the amount of acid that can be caused by CO2 being absorbed in the ocean water and reacting with other compounds and elements dissolved in the ocean water.

 

 The moral of the story – even if the world is warming by whatever mechanism, the coral reefs will adapt and the degree of ocean acidification will level out. That puts out the lights on two global warming alarms.

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