Oh boy, another energy miracle

AN amusing news item that briefly bubbled to the top of the information stew last week was an announcement by scientists at the University of the Philippines that their research had “found evidence of the presence of gas hydrates in the Manila Trench.” This was immediately followed by a proclamation that this “can be a great source of alternative energy,” although the scientists stressed that “more feasibility studies need to done” in order to “establish mechanisms to maximize the use of the alternative energy source.”

I can do the relevant feasibility study in four words: Not going to happen.

Gas hydrates are an example of a class of materials called clathrates and are a form of ice in which gas molecules, most often methane (CH4), are trapped within the water ice’s crystal lattice structure. Hydrates were first identified by Sir Humphrey Davy in the early 1800s, and their presence in the ground on land and under the seafloor has been known since the early 1900s. Gas hydrates can form underground on land at temperatures below freezing and are often found within the permafrost in arctic regions. Under the sea, they can form at temperatures above freezing at high pressures in the continental slope seabed anywhere from just under the surface to depths of several hundred meters. The hydrates for which the UP scientists found evidence in the Manila Trench are of the latter variety, lying at depths of several dozen to several hundred meters beneath the seabed.

There were two mildly annoying things in the way the UP scientists characterized their “discovery.” First, gas hydrates are, in no sense, an “alternative energy source.” It’s natural gas, methane, with some proportion of other light hydrocarbons such as ethane, pentane, butane, and propane mixed in. I suppose one can say natural gas is literally an alternative to other fuels, such as wood or cow dung, but there is certainly nothing unconventional about it. Second, it really wasn’t much of a discovery; the UP scientists, in fact, may have been the last to know that the South China Sea hides a vast volume of gas hydrates.

Hydrates can appear in the form of white ice, or more often, as the ice binds frozen sand and sediment on the ocean bottom. While the existence of hydrates has been known for a long time, it is only in the last 30 years or so that scientists have begun to understand just how much of it exists. It is estimated that the amount of carbon bound up in undersea hydrates — from which we can make a rough inference of the volume of gas present — is equal to between 100 and 500 times the annual amount of carbon emissions from burning fossil fuels. A 2001 study for the US government calculated that just within the US exclusive economic zone (EEZ), there are as much as 200 quadrillion cubic feet of methane in undersea hydrate deposits — about 28 times the known global reserves of natural gas. And that’s just in US territory. Multiply that amount by 10, or more, to account for the world supply of gas hydrates.

However, all that gas may as well be on Neptune for all the use anyone here on Earth can put it to. I would invite the UP scientists and anyone else who might be getting their hopes up that the Philippines can soon tap what would be a practically infinite source of energy to contemplate why no other nation on Earth has ever come close to commercial production of hydrate gas despite having a fairly good understanding of its hypothetical potential for several decades. Several countries have tested extraction methods, with the most recent seeming to be Japan in 2013 and China in 2017. Those experiments, while apparently technically successful on the scale of one or two test wells, have not expanded.

The main reason for that is extracting gas hydrates from the seafloor is extraordinarily risky, which, of course, makes it extraordinarily expensive. Getting the gas out of the ice is easy; all one has to do is raise the temperature by a small amount, so the drilling process is just a matter of injecting warmer water or some kind of antifreeze solution into the hydrate bed and pumping out the released gas. Doing that in a controlled manner, without causing a chain reaction in the hydrate deposit that causes it to melt all at once, is monumentally difficult. If the methane is released under the seafloor and cannot be captured by a well, it will simply escape.

The best-case scenario is that it finds a path through the seafloor material and bubbles up to disperse into the atmosphere. There, it is just a potent greenhouse gas that will contribute to the planet’s steady increase in atmospheric temperatures. The more dangerous possible outcome is that the released gas builds up enough under the seafloor that it makes the overlying sediment layers unstable, leading to a large-scale undersea landslide. As most of these deposits lie on continental slopes, most are at risk for this, and scientists have found scars of such landslides in several locations around the world. One highlighted on the web page about gas hydrates put up by the US National Oceanic and Atmospheric Administration occurred off the coast of Scotland about 7,000 years ago and caused tsunamis high enough to reach tens of kilometers inland.

And, of course, in such an event, all of the methane and other hydrocarbon gases under the slide area are released into the atmosphere all at once. The resulting addition to the Earth’s atmospheric warming could be enough to tip the delicate temperature balance, keeping other hydrate deposits frozen under the seas or in arctic permafrost, releasing more methane and increasing atmospheric temperatures even more in a feedback loop known as the clathrate gun (because it will fire off continuously, like a machine gun). The last time in Earth’s history that scientists are definitely sure it happened was in the late Pleistocene Era, about 55 million years ago, when the planet’s temperature increased between 5 and 10 degrees Celsius almost instantly. If that were to happen today, it would melt all the ice in both polar regions and all of the continental glaciers, raise global sea levels by several meters, and turn much of the current temperate regions of the planet — otherwise known as the places where we get most of our food — into a desert. Good times.

Even if the technical difficulties could eventually be overcome within a useful timeframe, the hydrate deposits identified in the vicinity of the Manila Trench are inaccessible to the Philippines, even for the purposes of carrying out “feasibility studies,” because almost all of the potential hydrate field lies within the part of the South China Sea claimed by China with its so-called nine-dash line. That claim is, of course, complete BS and an affront to both international law and Philippine sovereignty, but at this point, the chances of getting China to accept that and actually allow the Philippines to carry out economic activities in its own EEZ sometime before the heat death of the universe seem remote.