Photo by Gandroid.

News flash: World leaders will gather in two short months at the 2012 Earth Summit in Rio de Janeiro to discuss the future of the planet. You may have caught the news stories last week about President Obama’s failure to RSVP. You’re forgiven if you missed them. You’re not the only one who just said, “Earth Summit, what?”

But this is for real. And there are a few things that you, good Jedi knights, ought to know about it.

1. It’s kind of a big deal.

The Earth Summit, which comes along once every decade or two, is a chance for world leaders to sit down and consider where Spaceship Earth is headed, and whether we might be wise to chart a different course.

The original Earth Summit, held 40 years ago in Stockholm, Sweden, marked the first global effort to address the mess we humans were making of the planet. The second Earth Summit was held in Rio 20 years ago (which is why this year’s summit has been given the idiotic nickname “Rio+20”). That conference resulted in a major commitment to protect biological diversity and the climate change framework that led to the Kyoto Protocol.

The third Earth Summit (aka “Rio+10”), held in 2002 in Johannesburg, South Africa, produced little action on the international level in part because George W. Bush boycotted the meeting. A delegation of U.S. members of Congress, mayors, and environmentalists helped spark change on the local and regional levels, however.

There have been a million forums and conferences and high-level meetings in between, but the Earth Summits are biggies — and this year’s has an especially worthy mission: to lay the groundwork for a green economy that both saves the planet and wipes out poverty. Winning!

2. There’s a reason you haven’t heard of it.

Unfortunately, the United Nations has a habit of making things inscrutable to anyone who doesn’t have a master’s degree in international policy. (Did I mention the stupid nickname? Marketing tip No. 1: Come up with a title that actually has some meaning outside of a small circle of graying tree-huggers and policy wonks.)

The U.S. government, which has provided almost zero opportunity for meaningful public input, hasn’t helped matters. The media hasn’t exactly been on top of the story, either (guilty as charged), and aside from a few well-hidden blogs, environmentalists have flubbed their efforts to get the word out.

Hell, if U.S. Special Envoy on Climate Change Todd Stern hadn’t slipped up last week and told The Washington Post that Obama might be a no-show, the Earth Summit might have come and gone, with none of us any the wiser.

3. It’s going to bomb unless we get our asses in gear.

Listen, I get it. We’ve been burned too many times by these high-level gab fests. We watched U.S. leaders dodge the Kyoto treaty, and the 2009 climate talks in Copenhagen ended with a whimper. But to blow off the Earth Summit because it’s likely to produce nothing but hot air is a self-fulfilling prophesy.

Left to their own devices, the delegates in Rio will likely produce an endless list of toothless proclamations and platitudes — particularly if the U.S. isn’t firmly on board. Need proof? Take a gander at the 200-plus-page rough draft of the summit agreement, and then consider that in Rio, the document will be team-edited, line-by-line, by delegates from more than 100 countries.

“You don’t get the most inspiring and innovative policy out of these negotiations,” understates Tara DePorte, executive director of the Brooklyn-based Human Impacts Institute, a small nonprofit that helped create coalition called MobilizeUS to get people involved.

4. It might not bomb if we actually do bust out the lightsabers.

“This meeting still has huge potential,” says Jacob Scherr with the Natural Resources Defense Council, a self-described “summitologist” who has been a fixture at international environmental negotiations for decades.

Sherr is among those who are pushing individual countries to bring their own lists of specific commitments to the summit. He points to several hundred “partnerships” that grew out of the 2002 Earth Summit as examples of how this type of regional or country-by-country progress can work. He also hopes that cities, large corporations, and foundations will join national governments in pledging to do good.

And the real party happens outside the conference room. The Earth Summit comes with a whole carnival of side-events — some of them U.N.-sanctioned, some not — including the Youth Blast, TEDxRio+20, and meetings on science, corporate responsibility, and sustainable cities. Groups that think the U.N. process doesn’t go nearly far enough have organized the People’s Summit, which will “occupy” Flamengo Park.

5. You can help.

Please, tell President Obama to show up. Saying so sends him a clear message that we give a shit about the future of our planet. And if Obama goes, that puts pressure on all other world leaders to attend. (Besides, this is his chance to come off as a total intergalactic hero.) To make things easy, NRDC has created a Facebook petition, and MobilizeUS has a petition on Change.org.

If you want more information, the U.N. has created “briefs” on the critical issues that will be addressed, including jobs, energy, cities, and food. Jacob Scherr’s blog is worth reading. MobilizeUS has a hundred suggestions for ways you can get involved. (Write your representatives! Make a video! Throw a house party [PDF]!) If you want to go all out and drink from the fire hose, check out the U.N.’s Rio+20 website and the Rio+20 Portal from the folks organizing the People’s Summit.

And of course, stay tuned to Grist in the coming months. We’ll bring you regular updates in the lead-up to the summit, as well as live reports from Rio in June. As Yoda once said, “In a dark place we find ourselves, and a little more knowledge lights our way.”

Correction: This story originally stated that George W. Bush refused to even send a delegation to the 2002 Earth Summit in Rio. Not so. The U.S. delegation was headed by then-Secretary of State Colin Powell, who was heckled and booed when he defended Bush’s environmental efforts.