Standing beside Lake Erie, George Bush made a bold move this week to put greater distance between himself and the Reagan administration, at least when it comes to environmental policy.

In contrast to President Reagan's hands-off approach to many ecological problems, Vice President Bush announced a series of proposals for improving the environment, including promises to reduce acid rain and force polluters to pay for their mistakes.The Republican presidential nominee went on to pledge that during his first year in the oval office he would convene a global conference to discuss the greenhouse effect by which widespread air pollution is warming the world's climate and inflicting possibly permanent damage.

Though some see Bush's move as an attempt to take environmental issues away from the Democrats, it would be a mistake to dismiss his stance as just an exercise in political expediency.

After all, this nation has just gone through a particularly hot summer during which ozone smog reached levels as bad as any year on record, massive stretches of forests went up in smoke, and beaches were beset with new forms of pollution. This experience ought to make environmental matters rank higher on just about everyone's agenda.

Besides, it should be clear by now that conservationists and conservatives like Bush need not be in conflict. Instead, they share a core of common values. Their differences have centered not on whether or not to preserve mankind's natural heritage but on how deeply and actively government should be involved in the effort.

Moreover, it just might be that a new consensus is starting to emerge - a consensus that sees efforts to protect the environment not as a costly drain on the taxpayers but as a wise investment that eventually pays off in dollars and cents.

As a case in point, take the report a few months ago from the American Lung Association on the health costs of air pollution in economic terms. Among other things, the study found:

- The nation already is saving $4.4 billion a year in health care costs because of pollution control requirements in the federal Clean Air Act.

- Another $17 billion a year could be saved by a 20 percent reduction in the level of particulates and sulfates in the air we all breathe.

- A 60 percent reduction in particulate and sulfate air pollution levels could yield $25 billion in savings from reduced illness and another $5 billion to $15 billion savings from fewer pollution-related deaths.

These findings suggest, as the National Clean Air Coalition puts it, that "the cost in economic terms alone of living in a polluted environment is higher than the price tag for cleaning up."

If top politicians are finally striving to outdo each other in terms of which leader and policies can do the best job of cleaning up the environment, such competition should be the cause for cheers, not carping.