Today marks the 40th anniversary of Earth Day. A lot has happened in the 40 years since April 22, 1970. The modern environmental movement has transformed itself from a movement lead by counter-cultural hippies to one lead by companies like Walmart and institutions like Yale. Instead of suing the people polluting our planet, we’ve learned to work with them to find solutions. These are all accomplishments that merit celebration, but not every change that environmentalism has gone through has been for the better.

In the past few years in particular a subtle change has crept up upon environmentalism. The natural environment, the central element that the environmental movement was created around, is less and less a focus of our studies and attention. When we refer to the environment today, more often than not, we mean the built environment. In part this is because our actions have now influenced every natural environment on the face of the earth — even the most remote Arctic snows bear the charcoal mark of our industries, not to mention the air itself. If ever something could be defined as purely natural and outside of human influence, such a thing certainly does not exist anymore. Perhaps it is only natural then that we seek to study the environment not as something other and outside of our creation, but purely as something that we have intentionally created.

Yet, focusing solely on the built environment of our own invention misses so much that is part not only of environmentalism, but also our world. When we study only the built environment we lose an appreciation for the myriad interactions between the built and natural environments. We dredge marshes to build on swamps and then are shocked when floods destroy what we have built. We lament the fact that our valuable ocean-front property will be under water when sea levels rise but don’t stop to think about the fact that in clearing land to build our homes, we removed plants that were absorbing the atmospheric carbon dioxide that’s now making the sea rise. When we leave the natural environment out of our thoughts, we lose sense of that which links everything in our world.

In relegating the natural world to environmentalism of the past we lose one of environmentalism’s greatest strengths: its ability to engage ordinary citizens. Perhaps if we were to focus more on the natural world we would be able to see the changes being wrought in it more clearly. Rachel Carson was able to reach people in “Silent Spring” not through writing out the chemical formulas of various pesticides, but through her vivid descriptions of the effects that those pesticides had on the world.

Today’s environmental problems like global climate change aren’t as easy to convey to the public. We can’t watch the accumulation of carbon dioxide in the earth’s atmosphere. But we can watch something like the migration north of the chickadee. I grew up not far from here and though I remember hearing the cheerful chickadee’s cry often when I was a child, I haven’t heard it in a long time. Even though most of us would be hard-pressed to describe all of the feedbacks involved in the earth’s heat budget, we can all understand the changes occurring in our own backyards — as long as we look. I worry, however, that we no longer take the time to look, even those of us who call ourselves environmentalists, whose business it is to look and share what we see with others.

But if even the environmentalists, those people we used to call tree-huggers, have lost interest in the natural world, what does this say about everyone else? I hope that we haven’t completely lost our ability to connect with and appreciate nonhuman life. I can remember playing outside all year round when I young. By the time I was old enough to baby-sit for my neighbors, however, their children instead spent long hours inside protected from deer ticks and bee stings, but also isolated from the discovery of that first dewy snowdrop of spring and those last noisy geese of autumn. Will our own generation’s children learn only the names of cities, not the names of the flowers?

As this 40th Earth Day comes and goes, my humble suggestion both for those who call themselves environmentalists and those who don’t is this: Don’t forget the fact that the natural world is a part of your world, even here in New Haven. We might not be surrounded by the world’s most majestic mountains or loveliest lakes here in downtown New Haven, but life is springing into action everywhere we look — from the colony of sparrows busily nesting just inside the walls of Grove Street Cemetery to the occasional dandelion sprouting up through a crack in the sidewalk here and there, and even amid the urban castles of the University. You don’t have to go to the ends of the earth to appreciate the beauty of nonhuman life. All you have to do is recognize that it is already an intimate part of your own.

Lily Twining is a junior in Pierson College and a co-chair of the Yale Student Environmental Coalition.