Category: Under Water

In my last post, I talked about the fact that coral around the world is bleaching. Today, I want to talk about why this is happening.

First I need to explain something from Geology.

It’s called the Milankovitch Warming Cycle, and it has been used as a dog whistle in oil company propaganda, as evidence that the current global climate change is “natural.”

Let’s look at the cycle in terms of atmospheric CO2.

So, what exactly is the Milankovitch Warming Cycle?

Well, it describes the natural oscillation of the global climate since the formation of Earth. The global environment has varied in temperature in a natural cycle over hundreds of millions of years.

The key thing to know is that it happens very slowly.

When I say very slowly, you are probably thinking in human terms. I don’t mean in humans terms. I mean; it moves incredibly slowly in geologic time.

According to the natural cycle of our planet, it should take thousands of years for the temperature to change a fraction of a degree.

So why does it matter how fast the Earth warms up? Won’t it just cool down as part of a natural cycle and then all the plants and animals will go back to normal?

In a word, no.

To understand why, we have to talk about how organisms evolve. You see, evolution happens when a gene mutates and causes a new trait to appear in a species. If that trait is beneficial, it will help the offspring who have it to outperform their counterparts without it. This helps that trait survive.

It’s easiest to see when we look at specific examples, so let’s have a look at polar bears. There were not always polar bears. But that species came into existence when, during an ice age, a bears’ genes mutated and caused the offspring to be white. The white bear did better than the others because it could hide in the snow, and so it was able to pass on its genes year after year.

Over time, that single genetic mutation became a new species. But again, the key to all of this is that it happens slowly over time.

Now that we understand how slowly the climate is supposed to change and how evolution works, you should be able to see how those two processes have worked together in tandem since the Earth was formed.

In the past, the climate changed slowly, and animals and plants adapted slowly.

Unfortunately, the climate is changing too fast now for any life forms to evolve with it. So when the zooxanthellae inside the coral die, and then the polyps die, that is it for coral.

Some species are hardier than other and so they will die in future bleaching events. However, we do know that all of them will die. The temperature is simply heating up too fast.

The mass extinction event that we are witnessing is part of The Holocene Extinction.

The oil companies try to tell you is that the Holocene extinction is perfectly natural and couldn’t be helped. This is 100% untrue. Man-made climate change is currently happening because of our use of fossil fuels, and the death of the coral reefs worldwide is absolutely our fault. The body of evidence is overwhelming. Science has no doubt on the matter.

And so, the answer to the question of “Why is the coral dying?” is really very simple.

The answer is us.