AS might be expected, tomorrow's Earth Day will be somewhat different from its progenitor 25 years ago. For example, the thousands of activities are listed on the Internet, where computer users will also find experts like Environmental Protection Agency Administrator Carol M. Browner ready to chat.
But as striking as technological change has been, it is not as notable as the different public mood. In 1970, Earth Day was a worldwide wake-up call. An environmental crisis was at hand. Two events the year before -- the oil spill off of Santa Barbara, Calif., and the fire on the polluted Cuyahoga River in Ohio -- became icons of a natural world sorely abused. Automobile travel, would have to be abandoned because of air pollution. John Milton seemed to have summed up the situation three centuries earlier when he anguished: ''Earth felt the wound, and Nature from her seat/ Sighing through all her works gave signs of woe/ That all was lost.''
A quarter-century of progress has lifted that dark mood. In the 1970s, Congress forced major polluters of air and water resources to clean up. Other laws protected wildlife and natural areas. Just as important, an environmental ethic took hold with much of the public. Today, recycling household wastes is second nature to many Americans. And they often buy ''green'' products.
Earth Day 1995 should be a celebration of this progress. But it also must be a sober recognition of how much more is needed. Man's heavy footprint on the natural world still deepens. For example, many species of life are rapidly diminishing -- or even vanishing, sometimes before we know what vital role they may be playing in the ecosystem.
The Republican Congress is in danger of misinterpreting the public desire for a lighter regulatory hand from Washington as lack of interest in the environment. That would be a mistake. Any changes to regulations should be carefully considered and informed by unbiased scientific advice.
''Holy, holy, holy, is the Lord of hosts: the whole earth is full of his glory,'' the Bible's book of Isaiah reminds us. Every time we explore nature -- discover its fascinating variety, awesome order, and infinite beauty -- we gain guidance as we seek to love and protect our earthly home.