HALF THE time, environmentalists will tell anybody within earshot that mankind is helpless when confronted with the forces of Mother Nature, and that it’s foolishly arrogant for anybody to think he can stand in their way. And the other half of the time, they’ll lecture you that even the smallest manmade change to the environment can have disastrous consequences.

Both things can’t be true, of course, and anybody who has even briefly studied the geologic history of Earth realizes the former argument is the one that holds water.

Consider the tsunami that hit Japan March 11. While the wave that rushed onshore was “huge” and the earthquake that spawned it was “colossal” compared to the small towns filled with fragile wooden buildings that stood in their way, the events were practically nothing compared to the forces, for example, that created the Japanese archipelago to begin with.

Hurricane Katrina was a disaster for the people of New Orleans. But it was a trivial event compared to, say, the last ice age.

And the 1906 earthquake was awful for the City of San Francisco and the people who lived in it 100 years ago, of course. But a slightly larger series of earthquakes was required, for instance, to separate South America from Africa.

Humans could have done nothing to influence the course of the titanic geologic events that created the planet we live on today. But a lot of supposedly educated people act like the past never happened.

The phenomenon of believing the present is more important than the past, or that the way the world seems while you are in it is the way it’s supposed to be, is called “temporocentrism.”

Thus, someone who’s lived in Big Sur will be likely accept as “normal” that Highway 1 is going to be closed from time to time by landslides, but he’ll also think that a slide the size of the one that closed the highway at Alder Creek was “massive.” And so it was, compared to the size of a car that might have been in the way or a bulldozer trying to clear the slide now.

However, Big Sur is a dynamic place that is changing all the time. Over a period of many millions of years, the mountains rose, and they may still be growing today. But, simultaneously, their surface is constantly being broken down by microbes and plants, even as it is relentlessly under assault by wind, rain and the ocean. Far beyond our own imaginations, but in the blink of an eye as far as the Earth is concerned, those mountains will be rounded smooth and then disappear.

Over the last few millennia, that process has included frequent landslides in which the side of the mountains collapsed into the ocean below. Truly, this process is a natural, inevitable and necessary part of Big Sur’s mountain/ocean environment. And it is continuing today.

Which brings us to this week’s decision by the Monterey Bay National Marine Sanctuary and the California Coastal Commission that, in clearing the Alder Creek slide, Caltrans can push a large portion of the slide debris over the edge of Highway 1 and into the ocean below.

Longstanding environmental regulations would have prevented this step, requiring instead that the debris be hauled (in a procession of hundreds of dumptruck round trips) to a “storage site” somewhere else. This week, because the closure of Highway 1 is an “emergency,” the agencies decided to short-cut the usual process, making it possible to clear the road much more quickly.

But instead of declaring an emergency, they could have simply decreed a State of Normalcy, because the ocean is where the debris, and the entire mountain range, is headed anyway.