COLUMN LEFT/ DONELLA H. MEADOWS : We Can’t Keep Stealing From the Future : A sustainable economy--one that’s efficient and sufficient--doesn’t have to mean sacrifice.

As the world prepares for the Earth Summit in June, the global buzzword is sustainability. Governments and people are working not only to define that concept, but to achieve it just about everywhere except the United States, where there seems to be a determined effort not to join the conversation.

A sustainable world, says World Bank economist Herman Daly, would not use renewable resources (forests, soils, waters, fish and game) faster than they are replenished. It wouldn’t use non-renewable resources (fossil fuels, mineral ores) faster than renewable substitutes can be found for them. It wouldn’t release pollutants faster than the Earth can process them to make them harmless.

By that definition, there is not an economy on Earth that is sustainable. The human world is a long way from meeting the needs of the present, and it is borrowing massively from the future--not only by piling up money debt, but also by degrading the resources from which all real wealth ultimately comes.

It’s not surprising that some Americans would rather not talk about sustainability. We haven’t even the discipline to balance our government’s monetary budget, much less our natural-resources budget. We are only 5% of the world’s people, but we use 25% of the world’s resources and produce 25% of its pollution. Sustainability sounds suspiciously like belt-tightening, something for which America has no taste, especially in a time of recession.

But the funny thing is, sustainability need not mean sacrifice. It could mean a better world, sooner as well as later, for ourselves as well as our children.

If we decided to live sustainably, we’d start by eliminating waste. We’d discover that we could run this country with half as much energy as we use now (some technological optimists say one-fourth as much). We could also cut our materials budget in half by better recycling, by increasing the useful lifetime of products and by reducing extravagant practices such as over-packaging and junk mailing.

Those are efficiency gains, not lifestyle losses. Our showers would still be hot and our beer cold, our motors would turn, our drain on resources and our pollution flow would go down, and so would our monthly bills. If we used the savings to grow more--more people and more stuff for each person--we would quickly find ourselves unsustainable again. Halving the energy and materials use per car or house but doubling the number of cars or houses would put us right back where we started.

That’s why the next step after efficiency is sufficiency--the concept of “enough.” Enough people and enough to support each person fully, but not to ridiculous excess. Efficiency can be measured in numbers and achieved by technology. Sufficiency is something else again; it is a matter not of quantity, but of quality, not of technology, but of moderation, equity, morality. Our current world is much better at producing quantity and technology than quality and morality.

But that’s culture, not scientific law or immutable destiny. No one wants growth, constant expansion, physical swelling. Growth is not a human value; it’s a means to the ends of sufficiency and security. Once we have enough, no one wants more, unless it is sold to us as a cheap substitute for something else, something non-material. We don’t need bigger cars or fancier clothes. We need self-respect, identity, community, love, variety, beauty, challenge and a purpose in living that is greater than material accumulation.

It could be possible to support all the world’s people, now and in the future, at a sufficient standard of living and within the environmental limits of the Earth. That outcome will not come about from seeking ever more. It will come from seeking enough. It will take not only technical capacity and economic ingenuity, but also human wisdom.

What would a sustainable world be like? It would have no poverty and therefore, as in current societies where there is no poverty, a stabilizing population. People would have learned how to meet their material needs efficiently and their non-material needs non-materially--and therefore they would be much happier than they are today. I see no reason why a sustainable world couldn’t be democratic, market-oriented (with wise regulation), creative, dynamic, decentralized, flexible, diverse, tolerant and technically advancing.

Because of the limits of the Earth, we are going to have to redesign our human world in any case. We might as well design it to be the world we really want.