Other factors - also human generated - contribute significantly: methane, from organic matter decomposing beneath the water of millions of acres of rice fields, as well as the venting of digestive gases by the 1.8 billion head of cattle we raise annually; chloro-fluoro-carbons used industrially and in home appliances; nitrous oxide from the nitrogen fertilizer used in agriculture. We call these "greenhouse" gases - they trap the sun's infra-red radiation (heat) in the earth's atmosphere just as the glass traps the heat in a greenhouse. Some of these substances chip away at our protective ozone layer also, but that's another horror story.
Drell picked up those facts and much more. Here's more: we have already seen an increase of 1.5¡ F in average global temperature, putting us at the level of a brief natural increase registered during the middle ages, a period when plagues wiped out a third to a half of Europe's population.
We now see the northward spread of mosquitos carrying such diseases as dengue fever, malaria and yellow fever into areas previously too cold for them. They will soon have comfortable homes in California and throughout the southern United States.
Carbon dioxide, CO2, is the primary greenhouse gas. Without human interference, CO2 levels in the atmosphere range from 190 parts per million (ppm) during colder periods to 280 ppm in the warm part of the natural cycle. Relatively small changes can have noticeable effects; a shift of 100 ppm is significant. We're now close to 360 ppm and looking at 560 ppm sometime in the next century.
In the U.S., cars and trucks, which use 18 million barrels of oil daily, contribute almost 60% of the CO2 that gets into the air. Fossil fuel-driven power plants and steel and other industrial manufacturing add to that. The amounts are immense. Between1870 and 1970 we added 400 billion tons of carbon to the atmosphere piling on another 400 billion tons by 1990. If the energy conglomerates have their way and we use all the recoverable carbon in the earth before switching to other energy sources, CO2 could reach 1400 ppm; all mammals - that's us - and most other organisms will be dead.
Drell describes the natural cycle of warm to cold and back again as a result of changes in the earth's orbit, bringing us closer to or farther from the sun. Ocean currents move upward or downward, providing more or less carbon from the ocean depths, thereby requiring the masses of microscopic organisms that dwell in the seas to get the carbon for their shells alternately less or more from the ocean and more or less from the atmosphere. The climate changes, becoming warmer with the rise of atmospheric CO2 - when the animalcules draw carbon from the sea - and colder with its decline - as they draw carbon from the atmosphere.
We are now at the height of an inter-glacial period, something unseen for the past two million years. But instead of a natural decrease in CO2, we are causing this rapid, massive increase. That forestalls the forward movement of the glaciers (though some predict a slight glacier growth initially) but the rate of change is fast enough to have already created the unsettled weather conditions we are now experiencing: slight seasonal shifts, excessive precipitation in the form of record rain- and snow-falls (maybe even the recent snow in Mendocino County), super-strong hurricanes, twisters and the like. As things continue to warm up, glaciers will melt, adding enough water to the ocean to flood coastal areas.
We are already seeing some slow melting in Antarctica; ocean levels have risen 8-9 inches. Another ominous development is the melting of the permafrost in northern areas, a clear indication of the warming and a phenomenon which, because it releases yet more methane, could, together with other feedback loops, transform the process from a linear to an exponential one, speeding the process even more drastically.
As the warming trend develops, its worst consequences will show up as a decline in agriculture in the developing world, leading to mass northward migrations which will dwarf the current controversial flow of economic immigrants into this country from Mexico. The impact on northern hemisphere areas, where crops will still grow, will be massive.
To hold off these disasters, says Drell, we must halt our overuse of fossil fuels. That won't be easy. The multi-national energy companies are saying "Let the climate warm up; we'll see what happens; if problems come up, our technology will solve them."
They're using their political clout as well to shore up the status quo. A statement in the 1990 report of the Intergovernmental Panel on Climate Change (IPCC) reads, "The balance of the evidence suggests a discernible human influence on climate." Saudi Arabia, at the instigation of the "seven sisters" of the international oil cartel, successfully forced the substitution of "discernible" for "appreciable," the panel's original term.
The IPCC will be meeting next year to set goals for post-2000 greenhouse gas levels. (The Rio Treaty set those levels at no higher than 1990 levels by the year 2000, but it set up no mechanisms for reaching that goal). Global society needs to cut back on usage, but in a situation where the market mentality rules and carbon technology is the driving force, the prospects aren't good.
The situation isn't terminal. If we act now we can at least slow down the process and work to bring it to a halt, and there are some things happening. Certain business interests are already beginning to see the light. Banks have large loans out on coastal property and they're getting nervous. The insurance industry has already suffered tremendous losses from hurricanes, floods and other "natural" disasters. Those are powerful players with an economic incentive to use their muscle; the question is whether they will split with other industrial sectors - where they have other billions invested - or not.
In the meantime, more than a hundred cities are working to cut down significantly on fossil fuel use by instituting ride-sharing programs, improved public transit, energy efficient building requirements and lighting, even changing land-use patterns to cut back automobile use. That's a movement that should grow.
Individuals, too, need to watch how much CO2 they put into our atmosphere. Better home insulation, energy-efficient lighting, use of public transit, carpooling and saving up trips, recycling; all attack the problem. All long haul transport uses fossil fuels so we should buy locally, avoid imported items, get away from export-oriented agriculture and from all multi-national produced products.
And spread the word to your friends and neighbors and - very important - to your political representatives.
Copyright Mendocino Environmental Center 1997
Permission granted to excerpt or use this article if source is cited