People often complain that I warn a lot about climate change. A lot of people are convinced that it must be exaggerated in one form or another. They also tend to wonder “what about all the other crises we face”?
The response I have to that is that all the other problems are acute. With the climate problem, if we continue to screw this up, we’ll eventually trigger positive feedback processes that make the Earth uninhabitable to more than a few million human beings at best, for a very long time. We won’t be able to return to a simple agricultural civilization, we’ll be reduced to sparse bands of hunter-gatherers surviving far from the equator if we allow this to continue.
Most of the other problems on the other hand, with the exception of species extinction, can generally repair themselves within a few centuries. As an example, radioactivity decays or is buried in the soil, persistent pollutants known for their ability to “turn the frickin’ frogs gay” are eventually broken down and even soils regenerate themselves given enough time.
But if you were to say “climate change is not the only problem we face” then you’re right of course. It’s even true that some of the problems we face that are caused by climate change, are not entirely caused by climate change. As an example, I want to look at the droughts.
The Netherlands is currently on track to exceed the worst drought year ever recorded in my country’s history. From the website of the KNMI, we can find this graph:
It’s not hard to figure out that the rapidly changing climate is playing a role in this. As I must have mentioned a few times by now, whenever it rains now, it all tends to fall at once. In a forest, the trees will generally store the excess water in their deep roots and release it during dry periods. On the other hand, in our own agricultural fields, there are no big trees that can store excess water for drought years.
But as is so often the case, we humans make it all worse than it has to be. This brings me to an environmental problem you have probably never heard of yet, but you’re going to hear a lot about it in the coming years as humans begin to figure out the problem: Subsoil compaction.
What’s subsoil compaction? Well, when you press with something heavy on your soil, like the foot of an elephant, you compress the loose soil and remove any air gaps from it. When it’s all very dense, the roots of our plants can’t penetrate the barrier and the soil loses its ability to store water. To solve this problem, we generally till the top 20 centimeter or so of our soils. This helps to make the soil loose again and allows plants to grow.
Unfortunately however, when you’re using very big agricultural machines, like massive combine harvesters, then the weight of these machines is so massive that the deeper layers of the soil are being compacted, the area below 20 centimeters. This is where your plants are supposed to send their deepest roots, to extract micronutrients and water. When humans use big enough machines, the compression of the soil in these deepest layers makes the deep soil incapable of harboring life and storing water. The roots of our plants become incapable of penetrating this layer.
In the winter when soil temperatures drop below zero, water freezes and expands. This creates room for air in the soils again. However, the freezing temperatures generally don’t reach below 20 centimeters in most places. There are not really many mechanisms in nature that allow a soil that is compacted below 20 centimeters to recover its loose aerated structure that allows it to store water and harbor life. Studies from Sweden show that if you damage this layer of the soil with heavy machinery that rides over farmland, the damage remains for at least 14 years.
Unfortunately, the problem keeps getting worse, because we keep using bigger machines. With small machines, you damage the top layer that you then till to help it recover. With the big machines we’re using these days, we’re damaging layers that we don’t till. The soil is thus losing its ability to store water for us, as there’s a thick impenetrable layer forming.
You can see here how the machines we’re using are getting bigger and causing more damage to the subsoil by compressing it:
Stress at the surface of the soil isn’t really changing, but at the deeper layers, the problem is getting worse and worse, as the agricultural machines farmers use just keep getting bigger and bigger. The whole paper can be found here.
So it should be easy to understand what’s happening: We’re damaging the deeper layers of our soils, that used to store water for us, that plants with big roots could then use during droughts. When it now rains, this rain doesn’t penetrate deep into the soil, rather, it contributes to big floods and goes back into the ocean. Then when there is no rain, we don’t have any water reserves in our soils, so the droughts get worse!
As mentioned earlier, with the changing climate we now face a situation where water most often falls all at once instead of over an extended period. Forests are better able to deal with this than human agriculture, but with the way we are treating our deep soils, we are making it even worse!
Normally plants would also use these deeper layers of the soil, to find the micronutrients they can’t find in the higher layers of the soil. Today we can roughly compensate for most micronutrients plants are missing by using fertilizers, but without the fertilizers plants would now find themselves confronted with an inability to enter the deeper layers of the soil to find the micronutrients they need.
Agricultural yields in Europe began to stagnate in the 1990’s, it’s thought that this is related to the decline in quality of our deeper soil layers from the machinery we use. You can see here how the floods began to get much worse in Europe since the 90’s:
And here you can see the sudden stagnation in yields in Scandinavia from the 90’s onwards:
This is basically the equivalent of salting the fields: Our massive machines are damaging the deepest layers of the soil, where natural processes take decades or more to restore the vitality. The result becomes that the damage from any climate change induced drought will be more severe, as the crops won’t be able to tap into deeper layers of retained moisture.
This is an important thing to understand. In the decades ahead, you will start seeing increasingly worse food shortages and ecological problems. With every single problem, some people will say “see it’s climate change” and then others will say “well actually it’s due to X, Y and Z”! The reality however, is that humans are causing all sorts of changes to our environment, that are eroding our Earth’s capacity to feed us and give birth to life. The biggest out of all these problems is the changing climate, but with any individual crisis that we face, it will be a subject of constant debate which particular problem is mainly responsible.
In other words, in 2035 Joe Sixpack will still be able to argue that whatever new natural disaster has caused him to go hungry or watch his house burn to the ground was not caused by climate change, but by one form of mismanagement of our environment or another. If you’re really eager not to see it happening, then you’ll be able to come up with some sort of way to argue that it’s not really happening. That doesn’t allow you to escape the consequences however.
Consider for example, the situation in California. Americans don’t want to see what’s happening and so they can point to other problems: Forest fires are now prevented, so dry timber stacks up, causing massive fires when they do take place. Similarly, California had a dry period before the 20th century. In other words, as their whole state becomes an unlivable burning desert, they will argue that it’s not caused by the changing climate. By zooming in on any particular problem we’re facing, you allow yourself to grow blind to the massive global background problem that is throwing fuel onto each individual problem.