Mitigating the Climate Crisis: An Overview | Union Square Ventures

Overview of the Climate Crisis

Late last year, we announced the USV Climate Fund. At the time, we wrote that “mitigation is working on the causes of the climate crisis through either emissions reduction or drawdown of existing greenhouse gases from the atmosphere.” In today’s post, we want to provide some background on the scale of the problem, as well as a framework for thinking about different approaches.

Let’s first start with the observation that the accumulation of carbon dioxide and methane in the atmosphere is turning the world into a gigantic greenhouse. Sunlight can enter, but heat radiation (in the form of infrared light) is increasingly absorbed and then partially sent back down. In that regard, the gases act exactly like the windows on a car, which is why cars can get very hot on the inside, even on an otherwise only moderately warm day.

Here are the two charts that show just how rapidly the concentration of two crucial greenhouse gases has been rising in the atmosphere during the Industrial Age.

Carbon Dioxide (CO2)

Methane (CH4)

In each case, a roughly ten thousand-year period of stability (coinciding largely with the Agrarian Age) is followed by a nearly vertical increase during the Industrial Age.

These charts look bad, even if all you know is that they are charting something that’s causing a problem. Once you understand the magnitude of the problem, though, the charts look downright scary. Just how much extra heat are these greenhouse gases trapping in the Earth’s atmosphere and oceans that during the agrarian age was able to escape into space? The answer is a shocking four Hiroshima-sized nuclear bombs worth of heat every second. Yup. That’s not a typo. Every second of every minute of every hour of every day. That’s a lot of heat. We are not feeling it all that much yet because so far more than 90% of all that heat has warmed the oceans.

Now finally for some good news. The rapid build-up of these gases in the atmosphere is reversible. We know how to do it in principle. What we need is to take the initiative, which will require a combination of government regulation and entrepreneurial activity. To figure out what needs to be done, it helps to understand that the atmosphere is a bus stop and the concentration of gases within it is like a queue forming at this bus stop. Why? Because gases both arrive and depart from the atmosphere in large volumes. At a bus stop, if passengers arrive faster than they depart, then the queue builds (that’s the atmospheric concentration line going up). To reduce the queue, we can work on both sides of the problem: have fewer passengers arrive (work from home, ride a bike, etc.) and more passengers depart (more frequent buses, taxi pickups at the bus stop, etc.). The same goes for the atmosphere. We can work on both emitting less and on making existing gases depart the atmosphere faster.

Here are two charts that show the total atmospheric equation. The grey arrows show how much is arriving in the atmosphere, and the green arrows show how much is leaving it annually.

Carbon Dioxide (Annual Gigatons of C)

Methane (Annual Gigatons of CH4)

In both cases, the red arrow indicates the net arrival rate in the atmosphere. We need to basically reverse those arrows.

Let’s tackle methane first because the story here is relatively straightforward. Why? First, the amounts involved are tiny compared to carbon dioxide (smaller by three orders of magnitude). Second, we have big levers available that allow us to address the problem on the emissions side only.

Here are the sources for global methane emissions. We can see that about half (51%) of the emissions are from just two sources: oil & gas and the odd “enteric fermentation” (cows burping out methane). If we were able to cut those two sources by a quarter each, we would reduce emissions significantly.

Now let’s turn our attention to carbon dioxide. Here, the math looks rather different. As it turns out, only 4% of the carbon dioxide in the atmosphere is caused by human activity, which indicates that eliminating emissions from human activities alone to reverse the arrow is practically impossible.

Let’s look further into the global carbon emissions by sector. Every year, activities related to these sectors continue to increase without significant counteraction.

In future posts, we will discuss ways to reduce carbon dioxide emissions by focusing on electrifying transportation and alternative methods for generating electricity and heat.

But let’s be clear: reversing the arrow for carbon dioxide cannot happen quickly by focusing exclusively on emissions. We also need to enhance carbon sinks, which is known as carbon removal or drawdown. To completely reverse the current net increase, we would need to enhance these sinks significantly, requiring profound efforts such as large-scale tree planting and exponential protection of existing trees.