5 min read

On the Brink (Pt. 2 of 2); Methane Guns, The Limits of Tropical Forests

On the Brink (Pt. 2 of 2); Methane Guns, The Limits of Tropical Forests

A note before we dive in: I am at work on a letter about Gaza–because it feels impossible not to talk about–and I didn't finish it in time for yesterday–because my god, how do I attempt to write about it? But you deserve a letter so here is your previously scheduled letter, a day late and more than a dollar short.

Last week we discussed the acceleration of global warming and one of the reasons for that acceleration: the loss of atmospheric sulfur thanks to a decrease in pollution. Insert wry, pained smile.

This week we're going to discuss two tipping points–one of which I was surprised to find I haven't discussed yet at length. The other I learned was a thing a month or so back and it is just a heck of a bummer, so. Right. You don't come here to be cheered, do you? Because that's not starting this week, and next week ain't looking good either.

One practical matter before I get into the real stuff: because horrors never cease, a Midwestern drought has caused the Mississippi to falter, and its flow of freshwater into the Gulf of Mexico has weakened such that a lens of saltwater is flowing up into the river. This saltwater intrusion is unique in that it's going up an enormous river, but it is also a real problem for anyone near any coast, as saltwater can sneak into groundwater and kill crops, ruin wells, and spoil municipal water supplies. If ever you needed motivation to store some water, this ought to be it. The ocean flowing up a river–that feels end-timey, right? And for New Orleans in particular, the problem could cost quite a bit of money, as water infrastructure is, naturally, not designed to handle saltwater.

Flammable Ice

We've nudged around the idea of permafrost melt and methane release, but let's dive in, for a bit, and talk more in-depth about this subject. Methane is a greenhouse gas, just like CO2, but with two key differences: methane is far more potent, and much less long-lived. Sources of methane range from gases formed from decomposition in landfills and swamps to cow burps. But the especially dangerous source, the one that could really, really mess with our day, is methane found frozen at the bottom of various oceans, most notably the Arctic.

Through various processes, methane can become trapped under the ocean, condensed and literally caged within ice. These caged methane deposits are called methane clathrates, (or methane hydrates, somewhat confusingly), and there are vast stores of methane clathrates, much of them deposited in the relatively shallow waters off coastlines. Shallow waters are particularly susceptible to temperature change, which means that these clathrates, as the oceans warm, are in danger of being released, not entirely unlike an evil villain in some cartoon.

Methane is released from sedimentary deposits and clathrate deposits all the time as a natural part of the geologic cycle, but just as all previous extinction events were also natural, this isn't always a good thing for life on Earth. The theory of methane-driven extinction is called the clathrate gun hypothesis. A release of methane–not necessarily enormous–has the potential to increase the temperature of the planet by several degrees Celsius, and that, naturally, would set off a release of the rest of the clathrate deposits, which would warm the planet such that most everything would perish.

Now, the IPCC has stated that they are not concerned about methane clathrates–they consider the odds of a release very low especially in the near future. But a recent study (just one), suggests that the threshold of release may be lower than previously understood, and the lower end of that lowered threshold is where we currently reside. It is, regardless, such an enormous threat as to warrant keeping tabs at the least.

Photosynthesis' End

A study conducted on the world's tropical forests has determined that there is an upper limit to the temperatures that leaves are capable of withstanding, a limit above which they quit photosynthesizing. This is, luckily, an actual future worry and not a potentially-tomorrow-worry, but it is nevertheless concerning when you lump in an enormous tipping point like the Amazon. At temperatures being recorded today, using some pretty incredible sensors, scientists have been able to detect the shut down of photosynthesis "machinery" in individual leaves of tropical trees. Individual leaves temporarily shutting down is not a major concern, because, as you might be aware, trees usually have a lot of leaves. But the study suggests that we are approaching temperatures that will make this shutdown more widespread, and we are, of course, only headed faster in that direction.

Trees are obviously great and our friends, even if that friendship is extremely one-sided (sorry trees). But where this problem gets complicated and troubling beyond "tree-friend is hungry because hot" is that ecosystems like the Amazon are in a precarious position, and the potential death or illness of trees from an extended heatwave (in a region that is currently leaving winter with freakish heat) makes that position even more fragile. Though there is currently a non-fascist in the Brazilian presidency, meaning the Amazon is much better protected, there isn't much that can be done against a heatwave. Killing off even a small portion of trees in future hot conditions could mean the complete collapse of the Amazonian system, which would then upend one of the world's biggest carbon sinks and the world's metaphorical lungs.

What I'm Doing

We've been light on the basic and practical stuff, so I thought I'd walk you through what I'm up to on my end as I watch records break and the ends of cartoon thermometers shatter.

I have been focusing my prepping energy almost entirely on increasing our food stores. I'm nervous about grain prices given the numerous crop failures of the past summer and the continued pressure from the war in Ukraine. Water is on the backburner but not far from my mind. On both fronts, I've got well over a month socked away, but I'm trying to work up to two while diversifying the kind of food being stored, both for the sake of morale and nutrition. To complicate matters, we've started feeding our dogs homemade food (which I recommend for a whole slew of reasons), meaning we have to keep fresh meat in the house–a new problem seeing as how we're almost entirely vegan. Since I can't just stack bags of kibble, I'm now looking at purchasing a chest freezer. But that's another machine running on electricity that can go out and then we've got dozens of pounds of ruined meat. So you see, whether you're new to the idea of prepping for the collapse or not, you run into the same problems as a vet–I need to afford food and find ways to keep it around. That necessity doesn't change, at any level.

Having prepped for a little while and written When/If for three years, I'll admit to you that I'm finally at a point where all this thinking about collapse is wearing on my mind–and that's because it's become much more real. This summer was frightening, and the news from scientists is bleak. I barely have time to consider the human threats because climate collapse is here, now. But we truck on, right? We stare down what's coming and we prepare to make things as livable as we can. So go buy a sack of rice and a water container. We're gonna need both.