The Climate Crisis and the Deceptively Small Numbers Involved

Can we get serious now?...

I was once at a concert with Simon&Garfunkel and I clearly remember Paul walking up to the microphone saying "I need to say this"... All 40,000 spectators went pin-droppingly quiet and listened carefully to his next sentence.

I always thought that this was a badass way to open up a monolog but I never got a chance to try it. Well here goes...

I NEED TO SAY THIS...

Denmark has an election coming up tomorrow (Tuesday, November 1st), and yesterday I watched a political debate sent on National TV where each of the party leaders debated the major problems and obstacles that we face right now.

I won't write about politics per see. I simply don't think that this is the right medium for that. However, I would like to write about science and knowledge sharing. This is not a scientific paper so please don't treat it as such. This is simply my take on the situation as I see it.

The reason that I am writing this is simple. I was shocked by the apparent lack of understanding of our situation by many of my country's potential future political leaders. The reason I am writing this in English is that what I am about to inflict upon you is not only true for the Danish people but for all the people in this world (and in general, Danish people are quite good at English).

So here goes...

Communicating Science

Clearly, we have a communication issue. I suspect that one of the reasons that climate science is so hard to communicate is the apparent "small" numbers involved.

In Denmark for example, we have temperatures ranging between -30°C and 35°C so when people hear or read about a global average increase in temperature of a couple of degrees, I think that the psychological effect of processing the relatively small number is that the subconscious part of the brain labels the information as "not important".

This is dangerous because obviously, it is not about the number, it is about the effects that would follow from such increases in temperature.

Scientists have found that from 1900-2020, the world's surface air temperature increased an average of 1.1°C (nearly 2°F) due to burning fossil fuels (the numbers vary a bit from source to source so please don't shoot me if I got the second decimal wrong - the point is the same). The best models we have right now predict that unless we do something drastic about the emissions right now, temperatures are going to rise to 4, 5, or more degrees Celsius at the end of the century depending on the model in question.

But what does the above really mean? After all, these numbers seem quite low. right? I here state some highlights of our problems...

The first thing to understand is that the average doesn't say much about the data. If I have two people of age 5 and 75 years respectively, the average age is 40 years. Does that give us much information about the different ages in the dataset? A similar average is found for the dataset containing two people of 38 and 42 years old. What we are really after is the local variances together with the average - that is, how much the temperatures vary from the mean in different parts of the World.

For example, violent tropical storms can only form when water temperatures go above a given threshold - about 26 °C it turns out. At "only" a 2°C increase, this threshold will be crossed much more often by even the most optimistic predictions because of the local changes in temperature together with the global average increases.

That means not only more frequent storms but also more intensive storms since they are fueled by the water temperature.

The warmer temperatures will increase the precipitation due to more water vapor in the atmosphere. This will have many consequences - many of which we are not sure about.

Obviously, this will lead to more frequent flooding in some regions destroying people's homes. With a 2°C temperature increase, heavy rain events are expected to become 1.7 times more likely, and 14% more intense but again, this will not be evenly distributed. Some regions will be hit much more severely.

As the climate warms, snow and ice melt. This has a wealth of frightening consequences. The summer thickness of sea ice in the Arctic is about half of what it was in 1950. That is with "only" about 1°C average increase! What do you think happens when we hit a 2 or 3°C increase? Already in the early 2000s, biologists recorded for the first time that polar bears are drowning because they can't find ice. Polar bears can swim more than 300 kilometers!

The melting, in turn, causes the water levels to rise via (primarily) two mechanisms:

1. Melting glaciers and ice sheets add water to the oceans, raising the sea level, and
2. Ocean water expands as it warms, increasing its volume and thus also raising the sea levels.?

By 2100, without immediate reductions in greenhouse gas emissions, global sea level rise is expected to be more than 1 meter.?Again, that may not sound like much, but this is an average and some regions will be completely gone. Not to mention low ground-level areas important for harvesting rice for example.

These consequences will not affect millions. It will affect billions of people. Sickness, homelessness, orphanhood, and death will follow.

Large-scale ocean currents (called thermohaline circulation if you want to impress someone), driven by differences in salinity and temperature may also be disrupted as the climate warms. Changes in precipitation patterns and the influx of freshwater into the oceans from melting ice can alter salinity (the amount of salt in the water). Changing salinity, along with rising water temperature, may disrupt the currents. In an extreme case, the ocean currents could be disrupted or even shut down in some parts of the ocean, which could have large effects on the climate.

Some changes to the climate are gradual and predictable, while others are more sudden and difficult to foresee. The latter is often referred to as “tipping points.” A tipping point is a large and sudden change that cannot be stopped, even by employing drastic measures.

It is a little like rolling a big stone up a hill. We are right now pushing the stone uphill and we can choose to slow down, but if we don't, then there is a possibility that we accidentally push it over the top. Once this happens, we cannot stop it. Let me tell you, we are very close to the top in many regards and apparently, no one wants to hit the brake.

Some of the tipping points that we face are the collapse of major ice sheets, and disruption of ocean currents, along with other more exotic ones. But there are also more subtle tipping points. The harsh truth is that we don't know exactly what is going to happen with 3-5 degrees Celsius average increase. Nature is simply too complex. The most pessimistic models are routinely being updated by more pessimistic ones. This is not because the scientists are not skilled - they are. This is because Nature is filled with chaotic systems and we simply don't know all the hidden tipping points. It might be that 3.2°C increase on average is one of those tipping points that will create a runaway effect. We don't know!

Hard Decisions

The storms, floods, hunger, generation gaps, and potential wars that we might face will already be a threat at a 2 or 3 °C average increase. What do you think will happen at a 5°C average increase?

We have already reached some tipping points that unfortunately make it unrealistic (really impossible) to stay below 1.5 and also 2.0 degrees increase on average. That, however, doesn't mean that we should give up. On the contrary. We need to make some hard decisions, they need to be on a global political level, and we need them now - as in right now. And no, "Danmarksdemokraterne", we can't simply "pause the climate crisis and let the farmers have some peace and quiet to figure things out" as you suggested in yesterday's debate.

The climate knows no country borders and no culture. It doesn't distinguish between humans, other animals, or plants. It only reacts to physical laws. It doesn't care that we have inflation over us or that farmers need to eat too - physics doesn't sleep nor pause. This shouldn't be about when to react, but how to react. I am not saying that the "how" is trivial - it is not. I am just saying that we need to act right now - as in today.

Take a good look at the following image from NASA.

This is an image of Saturn's majestic rings. But if you look closely, you'll notice a small bright blueish dot in the background slightly to the middle-right in the image.

This is our home seen from space. This is Earth. Every historical event that ever happened, happened right there on this tiny little sphere. We are literally in the same boat and we don't have any lifeboats on board. We should all stand together and fight for our survival. We have an obligation (or an opportunity depending on how you see it) to show future generations that we care about them. If we don't set a new course right now, it will be too late and we will be known as the most selfish generation in history.

So please, all fellow Danes reading this, keep this in mind when you vote tomorrow. Help save lives. After all, we are one family under the skies.

By now, you are probably asking yourself "but what did Paul Simon say?"... He said: "This is an unusual place to listen to music". I know that LinkedIn might be an unusual place to write about the climate crisis, but I hope that those who are still with me will help carry the message that "small numbers do not necessarily mean small effects"!