By Donella Meadows

–June 30, 1988–

Thanks to the Midwest drought, reporters have caught on to the greenhouse effect. The phones of climatologists and environmentalists have been ringing off the hook. Experts on long-term climate change are quoted on the front page of the paper, asked to testify before Congress, interviewed on the “Today” show. Is the drought the first sign of global warming? Is the weather becoming irreversibly deranged?

This sudden attention is a surprise to the people who have been worried about the greenhouse effect for years. The reporters’ phone calls have spurred a round of calls among scientists discussing how to handle the situation. They are thrilled to be able to speak at last to millions of listeners about this longest-term, slowest-moving, potentially largest global problem. But they’ve gone through flurries of press interest before, and they’re aware of the perils.

If they say the drought IS a sign of global warming, they will be going beyond what they know. Furthermore, given the natural variability of weather, the drought will eventually end. When the next spell of rainy weather comes along, the same reporters who are now so eager to make a story of global warming will be tempted to make another story — about the “discrediting” of the greenhouse theory and the “doomsaying” of environmentalists.

If the scientists say the drought is NOT a sign of global warming, that will also be inconsistent with what they know, and it will allow people to go back to sleep on an issue that requires much wakefulness.

There’s another communication problem. The public tends to approach the future asking what will be, not what can be created. How bad will the warming be? What will we have to endure? But the crucial message is not about what will happen, but about what we can do to head off disaster.

Environmentalists are thinking hard in this time of opportunity about how to boil down what needs to be said to the basic minimum, and how to say it with the right degree of certainty and the right amount of hope. Here, after several of those phone conversations, is the best I can do:

We know that the concentrations of several gases (carbon dioxide, methane, nitrous oxide, chlorine) are increasing rapidly in the atmosphere.

We are quite positive that these increases are due to human activities, especially fossil-fuel burning and forest clearing.

We know that these gases trap the sun’s heat like the glass of a greenhouse. As their concentrations increase, they will increase the average temperature of the earth.

We don’t know how long it will take to detect amidst the normal fluctuations of the weather an unmistakable global warming. We don’t know that this drought is a sign of it. We do know that the four warmest years in the last 100 have been 1980, 1981, 1983, and 1987.

We know that small changes in average global temperature can make enormous changes in climate. A shift of just 1.6 degrees made the difference between the last Ice Age and now.

We don’t know what global warming means for local weather anywhere. There are theories about midcontinents being drier, coasts being wetter, and the corn belt shifting to Canada, but those are just theories. We do know that the warming will be greater near the poles than near the equator. That in itself is enough to shift patterns of rain, wind, ocean currents, and flows of rivers and groundwaters. The weather will change. We don’t know precisely how or where.

We know that if global warming persists long enough (we don’t know how long), sea levels will rise.

We know that present economies and ecosystems are dependent upon rain, wind, ocean currents, and sea levels being just where they are. More water in the desert would create havoc as certainly as less water in the farmbelt. The sea would not have to rise very far to threaten some of the world’s densest populations (Bangladesh, the Netherlands), largest cities (New York, Bombay), and richest farmlands (the deltas of rivers such as the Nile, Mekong, Mississippi). Forests would not be able to migrate, if their climate change faster than tree seeds can travel. Many species of life would probably become extinct.

We know what can be done to reverse the greenhouse effect — use coal, oil, and gas much more efficiently; switch to other energy sources; reforest the earth; control population growth; stop polluting the atmosphere with exotic gases.

We don’t know how much fuel efficiency, reforestation, etc. is necessary or by when.

We know all these measures are technically and economically possible. We don’t know whether the human race has the will, foresight, unity, common sense, empowerment, or attention span to implement them.

We know the press can help the situation immensely by maintaining its own attention, whether or not it rains in the Midwest. And by neither simplifying nor complicating what is happening. And by refusing, as far as is humanly possible, to be swept into either unjustified optimism or pessimism. And by continuing to point out that there may be cost and inconvenience in learning to live in harmony with the planet that supports us, but that is nothing compared to the cost and inconvenience of a global climate change.

Copyright Sustainability Institute 1988