Ocean Acidification due to Global Warming

[wxjay]

Originally Posted by workingclasshero

The ocean currently has a pH of 8.1, which is alkaline not acid. In order to become acid, it would have to drop below 7.0. According to Wikipedia “Between 1751 and 1994 surface ocean pH is estimated to have decreased from approximately 8.179 to 8.104.” At that rate, it will take another 3,500 years for the ocean to become even slightly acid.

There are a few problems with this line of reasoning.

(1) Why does the acidification have to linearly decrease? Most processes cause non-linear or exponential changes (population changes, for example). So, you cannot simply extrapolate to make a projection when the pH reaches 7.0.

(2) No one said the ocean is an acid. It is acidifying - meaning, its pH is lowering. Even you acknowledge that.

(3) There is an inherent assumption here that a small change in pH means nothing - that it is not until it crosses 7.0 that it is an acid and hence dangerous. The problem is that ecosystems are every sensitive to small changes to their environment. For example, take the human body. A change of ~3-5 F in body temperature either way from 'normal' can mean you are in danger (of being sick or hypothermia).

This does indeed sound alarming, until you consider that corals became common in the oceans during the Ordovician Era – nearly 500 million years ago – when atmospheric CO2 levels were about 10X greater than they are today.

And the ocean circulation patterns were very different back then, as were the creatures that roamed/swam on Earth. And how many humans were around at that time to feed off of this lush, life-flourishing planet?

In 1954, the US detonated the world’s largest nuclear weapon at Bikini Island in the South Pacific. The bomb was equivalent to 30 billion pounds of TNT, vapourised three islands, and raised water temperatures to 55,000 degrees. Yet half a century of rising CO2 later, the corals at Bikini are thriving.

Again, faulty types of reasoning. You can put your hand on a very hot stove for 1 second and get a mild burn. Or, you could leave your hand on a very hot stove for 20 years. Which one causes more permanent damage?

The corals might even survive a rise in ocean temperatures of half a degree, since they flourished at times when the earth’s temperature was 10C higher than the present.

Again, what species of coral survived 500 million years ago vs. today? You keep saying this and don't realize that organisms adapt and evolve over millions of years to changing environments.

[workingclasshero]

Originally Posted by wxjay

There are a few problems with this line of reasoning.

(1) Why does the acidification have to linearly decrease? Most processes cause non-linear or exponential changes (population changes, for example). So, you cannot simply extrapolate to make a projection when the pH reaches 7.0.

(2) No one said the ocean is an acid. It is acidifying - meaning, its pH is lowering. Even you acknowledge that.

(3) There is an inherent assumption here that a small change in pH means nothing - that it is not until it crosses 7.0 that it is an acid and hence dangerous. The problem is that ecosystems are every sensitive to small changes to their environment. For example, take the human body. A change of ~3-5 F in body temperature either way from 'normal' can mean you are in danger (of being sick or hypothermia).

And the ocean circulation patterns were very different back then, as were the creatures that roamed/swam on Earth. And how many humans were around at that time to feed off of this lush, life-flourishing planet?

Again, faulty types of reasoning. You can put your hand on a very hot stove for 1 second and get a mild burn. Or, you could leave your hand on a very hot stove for 20 years. Which one causes more permanent damage?

Again, what species of coral survived 500 million years ago vs. today? You keep saying this and don't realize that organisms adapt and evolve over millions of years to changing environments.

I never said that there had not been any changes

but the facts are there is more "acidification" from "deficated waste" (sewage) being let lose in the oceans, than from air polution.....remember there are 7 billion people (and many more animals) that all have to deficate

[GregW]

I believe the globe IS getting warmer due to geologically sequestered Carbon being burned by human activity. I do not foresee any diminution of the Carbon burning in the near future. I do see the changes in temperature accelerating. We will just have to sit back and watch this real time terraforming experiment.