On June 9, I published The Venus Syndrome in the Huffington Post. In short, I expressed a fear that carbon dioxide might not necessarily be our greatest terror. I said there is something about methane.
Well, this past week, MIT reported that methane has suddenly and uniformly increased in our atmosphere after a decade of general decline. The mystery was that this change was explainable for the northern hemisphere, the melting of the Artic tundra, of course. But what happened in the south? The usual suspects are mentioned, all terrestrially-based. That is a standard reaction of knowledgeable scientists. They tend to forget that the ocean covers about 70% of the planet Earth.
Did you know, for example, that there is more combined mass in the bacteria, viruses and archaea in the ocean than in all the larger life forms (fish, trees, you) in the ocean and on land? You've probably never even ever heard of archaea. Hint: like dark matter in space, archaea in our seas was relatively recently discovered, and virtually equals the mass total of bacteria.
The natural thing is that marine microorganisms at the surface expire, drop to the bottom of the ocean, and in an absence of oxygen, are converted into methane and other compounds, which, because of the pressure and temperature at depth, generally become trapped in ice as marine methane hydrates. It is said that there might be twice the energy in this methane at the seabed than all the known coal, oil and natural gas. Let me repeat: Twice as much energy in methane in metastable equilibrium at the bottom of the ocean than all the known coal, oil an natural gas deposits, which are rather safely resting deep underground. What happens to gas and ice when disturbed? Well, they rise to the surface.
Over our geologic history, every few ten million years, our planet naturally heats up. This is accompanied by heightened carbon dioxide and methane levels, or more probably, these gases caused the temperature rise... just like what is seeming to ensue today. Some scientists have speculated that the primary cause might well have been a rather sudden release of marine methane hydrates into the atmosphere. Chapter 5 of Simple Solutions for Planet Earth (icon found in one of the right boxes) provides all the science and speculations an interested reader might want.
Returning to that MIT report, is this methane increase a recent phenomenon? Actually, no. Since 1750 or so, carbon dioxide in our atmosphere increased by about a third, mostly, if not all, from burning fossil fuels. However, in this period, methane doubled! So there is something about methane.
But what's the big deal about methane in the air? Well, one molecule of methane is from 20 to 60 times worse than one molecule of carbon dioxide in causing global warming. According to some atmospheric scientists, this miniscule amount of methane in our atmosphere already has half the potency of carbon dioxide in warming our globe.
As an extreme worst-case scenario, let's take the case of our planetary neighbor. Venus is mostly carbon dioxide at a surface temperature of almost 900 degrees Fahrenheit. Could you imagine a scenario where sufficient methane contaminates our atmosphere to really cause trouble? Methane tends to oxidize into carbon dioxide over time. Ergo... the potential for an atmosphere and surface temperature on Earth like that on Venus.
Will this happen? I can't imagine that occurring, for our planet has been around for 4.5 billion years and we never got close to anything remotely that hot. Yet, could humanity's rush for progress stimulate a heating that, in combination with a perfect storm of events, catalyze the Venus Syndrome? Such a set of circumstances is presented in Part Two of The Venus Syndrome from the June 10 Green issue of the Huffington Post.
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Patrick Takahashi is a former special assistant in the U.S. Senate, professor of engineering and emeritus director of the Hawaii Natural Energy Institute at the University of Hawaii.