You see evidence of it everywhere: going green is going mainstream.

On line at the supermarket, everybody’s carrying their own canvas sack, making the old paper or plastic debate moot; on the store’s shelves, more and more products boast of being at least environmentally neutral; on the radio and on TV, news and feature shows all have a new “green living” segment; the cars are getting smaller, the bikes more plentiful.

Since at least the 1960s, and really long before that, a small, fiercely committed sidestream of American culture has been committed to the environmentally conscious lifestyle—a lifestyle dedicated to leaving a small footprint, using less and reusing more, eschewing the consumer thrall. These sandaled and backpacked folks are no longer on the outskirts of mainline living these days. Blame climate change, blame gas prices—you could even blame Al Gore and his chummy relationship with the Hollywood trend-makers. Regardless, the trend has dug in.

But will it matter, in the long run? And, more importantly, will it make any difference if you, as an individual, join the crowd and “go green.”

In a recent essay in the New York Review of Books physicist Freeman Dyson called environmentalism the “leading secular religion” in America.

“Environmentalism, as a religion of hope and respect for nature, is here to stay,” he wrote. “This is a religion we can all share, whether or not we believe that global warming is harmful.”

That may be true, but without all the dire warnings and apocalyptic reports these days about climate change the trend would likely be half as potent.

Most of us need a local connection and ground-level evidence to spur a lifestyle change. Gas prices and the concurrent price hike in everything connected with energy costs—that is, everything from food to building supplies—are likely, in the near future, to turn even the most skeptical into at least mild believers. But there are other, more subtle reasons why going green matters, especially for us desert-dwellers.

For these, we turn to Travis Huxman, Director of the University of Arizona’s Biosphere 2 lab and an associate professor of ecology and evolutionary biology. Huxley and his colleagues are using that infamous bubble in the desert north of Tucson to find out how climate change and drought are changing the very desert under our feet.

Huxman’s research is about how plants translate climate into ecosystem behavior—how plants respond to temperature fluctuation, co2 concentration, animals and microbes, and how a plant’s interaction with all these elements affects how an ecosystem processes water, which is probably the single most important question here in the arid, thirsty Southwest.

Plants can tell us a lot about ourselves, especially here in the desert, Huxman says.

“Deserts are very sensitive to change; you see big impacts in deserts before you might see them somewhere else,” he said during a recent interview in his campus office. He says that in the desert most of the effects of climate change are integrated into how soil moisture changes, and that he’s finding more boom and bust soil water characteristics, which is leading to a change in the kind of plants we see in the desert.

That means more scrub in the desert, and a movement toward a grassland-type system that is dominated by nonnative species. That in turn leads to an accelerated fire cycle and changes in biodiversity, changes, Huxman explained, to “the very desert landscape that makes this area so attractive to tourists, and less resilient landscapes for ranching and other uses of the desert.” And that includes potentially catastrophic changes to the watershed.

This means that big, representative species of the Sonoran Desert, most notably the mighty saguaro, are living under a very real threat.

“The changes in species composition is powerful to people,” Huxman says.

An individual, especially one that loves the desert, is likely to respond to the fact that we could lose the saguaro and other large components of the desert because of fires sparked by invasive grasses, the spread of which is a direct impact of global climate change. It’s happening in North America’s other deserts as well. In the Mojave Desert to the west, the great Joshua Tree is similarly threatened, he says.

“I don’t have a projection for how long it would take, but you can hardly drive a freeway through the north American deserts and not see this change and the impact of fire on these landscapes,” Huxman says. “It’s fairly obvious.”

Though a survey of the Sonoran is yet to be done, a recent assessment of the Great Basin Desert found that some 40 percent of the landscape has been affected by nonnative grasses, leading to a significant change in the character of the desert. In Arizona, such changes are most evident in the high deserts of the state’s north-central pinebelt. There, the largest Ponderosa Pine forest in North America is on the verge of total collapse. The conifers are stressed due to drought, and that stress allows bark beetles and other killers to dig in, which in turn leaves this typically fire-resistance species ready to burn. And once they’re gone, will they grow back, or has the ecosystem changed irrevocably? But that’s not even the biggest problem, Huxley says. What we don’t know yet is how the water cycle will react if a single dominant species like the Ponderosa Pine is no longer part of the ecosystem. “That’s the big research question,” Huxman says. “How will all this affect water?”

And that, according to Huxman, points to the most important fact we can learn from plants: what he calls the water-energy problem.

“Plants take up carbon dioxide in order to grow, but to do so they have to lose water to the atmosphere,” he explains. “That’s our problem on many different scales: How water and energy are related; so the most important thing we can do now is to remember that when we are thinking about energy efficiency, we are also thinking about water efficiency at the same time.”

In other words, it’s all related. When you turn off the lights, when you use a reusable tote instead of a throw-away bag, when you ride your bike to work, when you change to energy-saving light bulbs, when you, in essence “go green”—all those small, easy changes that are becoming so popular these days—you are also saving water. And water is one of the very few things that we all will always need.