CLOUDS OF DISPUTE COVER WORLD WARMING : POLITICAL HEAT VS. SCIENTIFIC LIGHT : Environment: As greenhouse politics become muddled, greenhouse science grows more clear--and ominous.
“High Cost of Greenhouse Hysteria.”
“Greenhouse Effect Looks Like Just a Lot of Hot Air.”
“Environmentalists, Not Pollution, Are the Real Threat.”
The greenhouse backlash has appeared, as is obvious from these recent newspaper headlines. Global climate change has not only been popularized, it has been politicized.
Those already unhappy with the state of the world are using one hot summer to call for major social reform. Those traditionally comfortable and conservative are resisting. They will probably deny the possibility of climate change until they see palm trees growing in New York and rising seas lapping the White House steps.
If we let public discussion of environmental matters degenerate into ideology, we will all be losers. The planet does not lean right or left. It follows its own laws, which we can understand, at least partially--and we will need all the understanding we can get to deal with the slow, complex, Earth-changing phenomenon we call the greenhouse effect.
Fortunately, as greenhouse politics gets more muddled, greenhouse science is becoming more clear. There are maverick scientists with extreme opinions, of course, but there is also strong scientific consensus--strong enough to debunk many politically popular greenhouse myths. Here are seven deadly ones:
Myth 1 . “We’re not sure there’s a greenhouse effect.” One of the first Nobel Prize winners, the Swedish chemist Svante Arrhenius, explained in 1896 how greenhouse gases trap the sun’s energy and warm the Earth. He warned that one of those gases, carbon dioxide (CO2), is released when we burn oil, gas or coal.
Nearly 100 years later his reasoning is completely accepted, and atmospheric CO2 has increased by 25%. The main thing changed since Arrhenius’ time is that we now synthesize gases he never heard of, such as Freon and other chlorofluorocarbons (CFCs), which are more powerful heat traps than carbon dioxide.
The warming effect of greenhouse gases is not in doubt. Nor is the fact that these gases are increasing. They have been measured directly for 30 years, and indirectly (from air bubbles buried in polar ice) for 200 years. Different gases are increasing at different rates, all of them in upward-rising curves. Each year fossil fuel burning, deforestation and pollution release more of them into the atmosphere than the year before.
If we allow these atmospheric changes to continue at their current rates, the equivalent of Arrhenius’s CO2 doubling will be reached about the year 2030--when a child born this year is 41 years old. That would produce an average global warming of 1.5 to 4.5 degrees centigrade. That range tells you how much scientific uncertainty there is--not in the existence or the direction of climate change, but in its exact rate of onset.
Because scientists talk so much about an equivalent CO2 doubling, people are beginning to see doubling as some sort of end-point to the greenhouse warming. It is only a calculation point. The warming will not stop there, or anywhere, unless we stop it.
Myth 2 . “Last summer’s drought was a sure sign of the greenhouse effect.” Specific weather events at any one place or time are not evidence for or against the greenhouse effect. Even the fact that the 1980s saw the five hottest years in the past 110 doesn’t prove anything. Weather is variable, noisy, shifting. A climate change can only be proved by keeping track of weather over decades.
The counterclaim by greenhouse scoffers that the contiguous 48 states have cooled doesn’t prove anything either. Such statistics represent only 1.5% of the Earth’s surface. The Earth as a whole has warmed by 0.6 degrees centigrade in the past century.
Myth 3 . “There will be time to act when a climate change is measured for sure.” The climate is the last place the greenhouse effect will show up. That’s not only because it takes so long to measure climate, but because the oceans and ice sheets act as delays or drags. Any climate change we detect now reflects what we put into motion decades ago.
If we want to deal constructively with the greenhouse effect, we have to measure not the lagging indicator, climate, but the leading indicators, greenhouse gases. Scientists use the word “commitment” to indicate the warming portended by the gases already in the atmosphere. So far we are committed to a warming of 0.5 to 1.5 degrees centigrade.
Myth 4 . “It will get warmer everywhere.” No one really knows what a greenhouse world will be like. As ocean and air currents shift, some places will be hotter, some colder, some wetter, some drier. Climatologists are using huge computer models to sort out what might change where, but the models do not agree. Anyone who tells you that the Soviet Union will grow more grain with global warming, or that the Midwest will dry up, or that there will be more rain in the Sahara, is going out on a limb. The one certainty is that “normal” weather will change just about everywhere.
Myth 5 . “We can adapt at reasonable cost.” Since we don’t know exactly what greenhouse weather will be like, easy claims that we can build dikes or move the Grain Belt north are just speculation, and uninformed speculation at that.
The most chilling speech I have heard about greenhouse implications was from a senior agricultural expert who pointed out that it takes years to learn local conditions well enough to farm successfully. Imagine coping with ever-changing weather and pests, with shifting ground water, with irrigation systems engineered for obsolete water regimes. Old agricultural traditions will fail. New ones cannot form as long as the climate is in flux, perhaps for 100 years or more, during which time Third World population is scheduled to double--and then double again.
If you add up the possible costs of what scientists are projecting--more forceful tropical storms, salt water infiltration of coastal ground waters, some rivers rising, others falling, inland droughts, flooding of coasts and estuaries--you ask less about the cost of adapting to all this and more about the cost of preventing it.
Believe it or not, there’s good news there.
Myth 6 . “Combating the greenhouse effect will require great, grim sacrifice.” By some kind of providence, every measure that will reduce greenhouse gas emissions is worth doing anyway, has other benefits and can be cost-effective. For example, here is a list presented last month to an international scientific gathering, of greenhouse prevention measures, in order of their effectiveness and urgency:
Use energy much more efficiently and accelerate the transition to solar, wind, hydro and biomass energy sources (would also reduce fuel bills, urban smog, acid rain, oil spills, toxic wastes and oil imports).
Phase out CFCs completely and quickly (a partial phase-out is already internationally agreed upon, at a leisurely schedule, to fix the “ozone hole”).
Shift fossil fuel use, away from coal and oil, toward natural gas (would reduce many air pollutants).
Stop deforestation, accelerate reforestation (would protect lumber, pulp and other forest resources, reduce soil erosion, flooding, and drought, moderate temperatures, preserve endangered species).
Increase use-efficiency and recycling of all materials and of water (would increase energy efficiency, with all the benefits listed above, plus reduce municipal solid waste, toxic waste, mine waste, water pollution and materials and ground water depletion),
Practice low-input agriculture (would reduce farm costs, increase energy efficiency, restore soils and rural ecosystems, reduce water pollution, improve health).
These measures require tremendous changes in our current, environmentally semiconscious ways of doing things. Changes, not sacrifices. Actually improvements.
But if we look at the gains to the whole society and take into account the very real social and environmental costs of continuing business as usual--especially the immense costs of not reducing the greenhouse effect--we would see there is no better payoff on the planet than greenhouse prevention.
Myth 7 . “The greenhouse effect is a problem of the rich countries/poor countries, capitalist countries/communist countries.” This is the favorite international political myth, a convenient way of shifting responsibility around the world. We point to the Brazilians burning their forest, they point at us wasting energy. Western Europe points at inefficient coal-burning in Eastern Europe (while the West Germans could save 26 million tons of CO2 emissions a year just by putting a speed limit on their autobahns). Everyone looks nervously at China’s plans to burn its huge deposits of coal. The Third World says it really has more immediate problems than some future climate change. We all suggest that someone else go first.
If there was ever a problem the whole world has in common, this is it. If we let it proceed full-scale, climate change will affect everyone and the effects will be devastating. There will not be winners and losers--only losers. Without a sense of global responsibility and justice, we will make a hash of this challenge. And we get only one chance--only over the next decade or two.
I would see no hope, if the the steps we must take were not possible, affordable and beneficial. It’s not a matter of allocating unbearable costs, but of building a more efficient, less polluted world--a world worth building, greenhouse effect or no greenhouse effect.
There is a greenhouse effect, though, pushing us toward environmental maturity. It’s very real. So far only a small amount of it is inevitable. Probably the greatest and most dangerous myth we could create about global warming is to call it a matter of destiny, rather than a matter of choice.
CARBON DIOXIDE CONCENTRATION
Time trend of the concentration of atmospheric CO2, at Mauna Loa Observatory, Hawaii. Line follows fluctuations in monthly mean concentrations obtained from a continuously recording gas analyzer.
