Methane and the Rest

by David Boehm

Greenhouse gases, which block and re-radiate the solar heat reflecting off our planet, have been increasing over the past 200 years as humans have increasingly interfered with the natural environment. The heat radiating back to earth is raising global surface temperatures, threatening to disrupt the relatively stable climatic conditions we've been enjoying since the last ice age.

The most abundant greenhouse gas is water vapor. With the exception of airliner contrails, our monkey business hasn't (as yet) had any large effect on this gaseous stage of the hydrological cycle. But we sure have tinkered with carbon, an element that cycles between earth and air much as water does.

Terrestrially, carbon makes itself useful forming the bodies of plants and animals and the fertility of the soil, and takes to the sky when its work is done, transformed into carbon dioxide through rust, rot, or fire. Some carbon gets diverted from this relatively quick loop and lies around for eons waiting for Mr. Peabody, Texaco, or DeBeers to dig it up. If it doesn't glitter and sparkle, it gets burned up in a Honda, or goes up the stacks at Point Tupper.

There has been a lot of this lately. Since the industrial revolution we've gone from 280 parts per million to 367 ppm of CO2 in the atmosphere - a 30 percent increase in less time than it takes to push a hemlock through the understory. Consider that an increase of just one percent in the amount of atmospheric oxygen would cause the spontaneous combustion of the world's forests, and you get a sense of why the wholesale dumping of carbon dioxide into the atmosphere could spell trouble.

Methane is really just an eddy in the carbon cycle. Methane (CH4) is carbon that gets tangled up with hydrogen when once-pretty things start to decompose anaerobically (without oxygen). It gets untangled again and transformed into CO2 when burned, or eventually in the atmosphere when it meets up with a long-haired radical hydroxyl. While methane is wafting on those zephyr breezes it soaks up a lot of rays. This longevity gives CH4 more than 20 times the warming effect of CO2.

Besides the methane-producing innards of cows, we can point a damning finger at swamps, dumps, petroleum extraction processes, manure piles, rice paddies, and assorted other mucky or murky enterprises. Atmospheric concentrations of methane have risen 150 percent since the beginning of the industrial revolution.

Even laughing gas isn't funny anymore. Nitrous oxide (NO2), the levity of the nitrogen cycle, is produced in tilled soils, and from applications of synthetic fertilizers and manure. NO2 has about 300 times the warming effect of carbon dioxide, and its prevalence in the atmosphere has increased about 16 percent since pre-industrial times. More bad seed from down on the farm.

Ozone is also a problem. It's the gas that always seems to be in the wrong place at the wrong time. Ozone makes trouble in the lower atmosphere when sundry air pollutants react in the presence of sunlight. This tropospheric ozone rates just behind carbon dioxide and methane in its accumulated effect on global warming.

The other major gases are exotic and hard to spell. They're mostly evil and, of course, man-made. They not only defy lay chemistry, but many of them persist in the atmosphere for thousands and thousands of years. Refrigeration, solvents, aluminum manufacturing, power transmission, semi-conductors . . . You can't blame everything on cows - though their ecological hoofprints follow closely on our heels.


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Research Extension Courses Consumers -------------------------- Virtual Farm Tours Student & Job Opportunities News Articles Links Standards -------------------------- Market Information Events Issues Animal Welfare Strategic Plans -------------------------- Award-winners Kids Stuff Rural Culture Discussion Forum Classified Ads Weather Site Map	Methane and the Rest by David Boehm Greenhouse gases, which block and re-radiate the solar heat reflecting off our planet, have been increasing over the past 200 years as humans have increasingly interfered with the natural environment. The heat radiating back to earth is raising global surface temperatures, threatening to disrupt the relatively stable climatic conditions we've been enjoying since the last ice age. The most abundant greenhouse gas is water vapor. With the exception of airliner contrails, our monkey business hasn't (as yet) had any large effect on this gaseous stage of the hydrological cycle. But we sure have tinkered with carbon, an element that cycles between earth and air much as water does. Terrestrially, carbon makes itself useful forming the bodies of plants and animals and the fertility of the soil, and takes to the sky when its work is done, transformed into carbon dioxide through rust, rot, or fire. Some carbon gets diverted from this relatively quick loop and lies around for eons waiting for Mr. Peabody, Texaco, or DeBeers to dig it up. If it doesn't glitter and sparkle, it gets burned up in a Honda, or goes up the stacks at Point Tupper. There has been a lot of this lately. Since the industrial revolution we've gone from 280 parts per million to 367 ppm of CO2 in the atmosphere - a 30 percent increase in less time than it takes to push a hemlock through the understory. Consider that an increase of just one percent in the amount of atmospheric oxygen would cause the spontaneous combustion of the world's forests, and you get a sense of why the wholesale dumping of carbon dioxide into the atmosphere could spell trouble. Methane is really just an eddy in the carbon cycle. Methane (CH4) is carbon that gets tangled up with hydrogen when once-pretty things start to decompose anaerobically (without oxygen). It gets untangled again and transformed into CO2 when burned, or eventually in the atmosphere when it meets up with a long-haired radical hydroxyl. While methane is wafting on those zephyr breezes it soaks up a lot of rays. This longevity gives CH4 more than 20 times the warming effect of CO2. Besides the methane-producing innards of cows, we can point a damning finger at swamps, dumps, petroleum extraction processes, manure piles, rice paddies, and assorted other mucky or murky enterprises. Atmospheric concentrations of methane have risen 150 percent since the beginning of the industrial revolution. Even laughing gas isn't funny anymore. Nitrous oxide (NO2), the levity of the nitrogen cycle, is produced in tilled soils, and from applications of synthetic fertilizers and manure. NO2 has about 300 times the warming effect of carbon dioxide, and its prevalence in the atmosphere has increased about 16 percent since pre-industrial times. More bad seed from down on the farm. Ozone is also a problem. It's the gas that always seems to be in the wrong place at the wrong time. Ozone makes trouble in the lower atmosphere when sundry air pollutants react in the presence of sunlight. This tropospheric ozone rates just behind carbon dioxide and methane in its accumulated effect on global warming. The other major gases are exotic and hard to spell. They're mostly evil and, of course, man-made. They not only defy lay chemistry, but many of them persist in the atmosphere for thousands and thousands of years. Refrigeration, solvents, aluminum manufacturing, power transmission, semi-conductors . . . You can't blame everything on cows - though their ecological hoofprints follow closely on our heels.
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Methane and the Rest

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