Every year on this date we seem to 'wake up' to an increasingly bleak picture of what we're doing to our planet, and we clean up some trash, buy a new energy-saving appliance or car, or participate in some other community project to show - at least symbolically - how much we care. And by morning the next day we go on living pretty much the same as previously, essentially hitting the snooze button on the climate alarm.

Fact is, a hundred fun and marketable products and/or lifestyle changes won't add up to a planet-saving effect, and neither is the energy industry's slow-motion shift to sustainable fuels, unless our species tackles the number-one environmental problem: animal agriculture.

And yes, it's a fact on which environmental-assessment scientists agree: Our gluttonous eating of meat and dairy is a bigger factor in climate change than all of our cars, trucks, ships and planes put together, and is a disaster in general for the environment. I thought I would spend a few paragraphs citing all the sources on this, but I don't need to because a bunch of other bloggers who get up earlier than I do have already covered it. So check these if you have any doubt that the most essential shift is to severely reduce consumption of animal products.

In short, go ahead and celebrate Earth Day in whatever way feels right. And then, tomorrow, get up and start moving yourself toward an animal-free diet.

Not every human may need to be vegan in order to reverse global warming trends - but a hell of a lot of us need to be very close to vegan, and since the United States is largely responsible for driving cultural choices in other, "upwardly mobile" countries, it would be a good start for you and everyone you know to get at least 95% of the way there. Yes, we're trending that way, but at what used to be called a "glacial" pace.

I'm not suggesting everyone's going to flip from one state to another overnight. Start where you are and add animal-free meals to your eating pattern, increasing the number as you go along. For those in Philly, you can use this site as a jumping-off point and get to sampling some of the large diversity of delicious vegan food our town has available (also some good ideas here). Find out which area of vegan cuisine is your favorite, and then help work to get more of it available - we're gonna need it, and soon!