Environmentalism is one of the most significant American movements of the 20th Century. The conventional wisdom is that Rachel Carson's book about pesticides' effects on wildlife, Silent Spring (1962), created the great awakening that led to the creation of Earth Day (1969), the National Environmental Policy Act (1969) and many other landmarks.

Within the 19th Century, there were predecessors to full-blown environmentalism. For instance, Henry David Thor-eau's Walden (1854) is regarded by some as a philosophical forerunner. Also Ralph Waldo Emerson's book Nature (1836) and the Transcendentalism that it sketches. President Theodore Roosevelt was a ground-breaking conservationist who enlarged the federal system of national parks and national forests.

In Oregon, Sen. Richard Neuberger (1912-1960) was an environmentalist ahead of his time. When he won election to the Senate at the age of 41, Neuberger was cited by The New Yorker as the most prolific freelance writer in America. He was an original sponsor of what became the Wilderness Act of 1964.

The Oregon Environmental Council, founded in 1968, has knit multiple groups together into a powerful lobbying force. The OEC'S considerable legacy includes the Oregon Bottle Bill (1971), the 1971 Beach Bill (affirming public ownership of beaches), statewide land use planning (1973), National Recreation Area protection for Hells Canyon (1975), Oregon's Safe Drinking Water Act (1981), curbside recycling (1983), the Climate Change Integration Act (2007) and much more.

It is fashionable for so-called conservatives to disparage environmentalists as trouble makers. But the political strands of environmentalism and its predecessor, conservationism, lead directly to the Republican Party and President Theodore Roosevelt. One of the oldest of the national environmental organizations, the National Audubon Society, was known for decades as an old-line Republican organization.

The importance of any pressure group - whether its cause is civil rights or environmentalism - is that it shifts the center of the national debate. And that is what the OEC has helped foster in Oregon. Environmentalism is not a fringe discussion. It is mainstream.

None of this should give the impression that Oregon is some kind of Eden. As a matter of fact, our state is known for its underfunded and lethargic Department of Environmental Quality.

The good news is that the Oregon Environmental Council, marking its 40th anniversary, is in good health and determined to keep environmental goals on the state's agenda.

The likes of Emerson, Thoreau, Roosevelt and Neuberger, could not begin to imagine the overriding environmental challenge of the 21st Century, global warming. That phenomenon is central to almost every threat to political stability and human welfare on the planet.