I would add a third bullet to the response: environmental values are consistent with religious values and can be held as a concurrently.

I am hoping that the environmental movement can begin to understand that to achieve real results we need to connect to the values of mainstream American culture, which identifies itself as religious, and use existing value systems to leverage change.

Religous values that can be used to support environmentalism include: a committment to stewardship of creation, a commitment to social and economic justice, and a commitment to promoting the health and well being of families and children.

And yet, hasn't environmentalism been promoting those very values for decades, now?  Stewardship, justice, health?  John Muir saw God's creation embodied in the Sierra Nevadas

And don't mainstream people -- presumably these same folks you describe as the religious majority -- consistently say in polls that they already believe that these qualities are vitally important?  (Will she stop asking rhetorical questions?)

Where's the connection been missed?  

While I haven't yet thought this through in a really systemic way, I wonder if environmentalism's progress into the mainstream was in fact derailed by the rebellion cultures of the 1960s and 70s -- back to the landers, pagans.  Think about where things were by the early 1970's -- post-Silent Spring, the nation's major environmental laws enacted one after another.  

But then green ideas seem to become inseparably linked to these (let's face it) fringe cultures in the public mind -- before you could engage on the issues you had to get over the hurdles of their associations with "radicals" and "hippies" and "tree-huggers."  And I have to note that of course, with all those big laws enacted, many people thought their problems were over.

That is part of what is so exciting now about the connections big businesses like GE are making between global warming and their bottom lines: it's environmentalism expressed in terms that can't be ignored under the dominant economic system.

Our concerns should not be limited to linking environmentalism to religious values -- those connections have existed across the life of the movement.  And they smack of the tendency towards preaching and moral uplift that bogs environmentalism down.  

My commitment to being part of saving the world is deeply spiritual, but it has nothing to do with beliefs about religious matters, and I don't worship anything--not "God," not "Nature" (which doesn't even exist, at least not in the usual sense of "everything on the planet that isn't human or humanmade"), not anything else. By the same turn, I don't really care what other people believe; I only care what they do.

When those who wish us ill toss the "environmentalism is an alternative religion" charge at us, I think we would be wise to remind our attackers that beliefs are private and personal, then flip it around and start talking values. Values are what really matter, not religious beliefs, because values are the underlying drivers of all our behavior. And if you want to know what someone values, watch what they do, don't listen to what they say.

I also think we need to forget embracing stewardship in order to bring large numbers of people of faith on board with saving the world. We have no more business casting ourselves as stewards of the world than do porcupines or petunias. We are a product of evolution just as every species is, and no species has the wisdom to run the world--nor does the world need us to run it. It's run itself just fine for billions of years. This is not to say that humans "don't matter as much as the rest of the...world" ("natural" excised because I don't accept that particular imaginary division) but it is to say that we, collectively, don't matter any more. We, collectively, matter no more nor any less than any other species. As an individual, I certainly value those I'm close to more than those I'm not (human and other), but that doesn't mean I would be willing to do anything, no matter how destructive to the rest of the world, in order to try to preserve those I'm close to. Why? Because I value the world, too. Values are certainly not always congruent or coherent, and it's when values come into conflict that get really interesting.

The world is sacred and I am sacred as part of it.

This religious prejudice against the original natural religions keeps surfacing over and over again.  I'm not sure exactly why?

Does drawing a spiritual boost from nature embarrass modern people?  Strange.

I find it completely compatible with science, reason, and real christianity that follows the life example of jesus.