The Sierra Club is devoting this entire week to helping use America's Best Idea to build a new generation of activists for the national parks.

It's officially Climate Week. In case you feel discouraged that you can't do enough, remember Gandhi's words: "Almost everything you do will seem insignificant, but it is very important that you do it."

How cool is it to be watching a special one-hour excerpt from Ken Burns's 12-hour PBS special on the National Parks in the White House screening room with President Obama?

It seems many people support wind and solar energy so long as it's not in my backyard, and not in my hiking grounds either.

For the eight years of the Bush Administration, permits were being issued that violated the Clean Water Act, but EPA was prevented from objecting. Clearly there is a new sheriff in town.

Going green doesn't just save the outside world. It also can preserve the hard-earned money in your bank account.

While the good folks at U.S. News and World Report ascribe certain measurements of prestige to their college rankings, we rated schools based on what matters most to us.

Three years ago Dynegy launched plans to partner with LS Power and become the largest new developer of coal-fired power plants. Yesterday Dynegy officially terminated those plans.

There's considerable evidence that these astroturf corporate lobbying operations are also trying to derail clean energy jobs legislation.

JPMorgan Chase is pouring billions of dollars into dirty coal plant projects -- projects that would dramatically increase global warming pollution and ensure runaway global warming.

A burst of developments Monday considerably raised the profile of the latest attempt by polluting industries to thwart environmental legislation through fraudulent mailings to Congress.

Three generations of Gandhi-inspired environmental activists are on the stage. They haven't forgotten his emphasis on empowering local people and developing India from the bottom up.

Last week when we hit the 100th coal-fired plant abandoned or prevented in the U.S., someone asked me, "What's next?" My answer came quickly: "It's time to stop the next 100."

The smelter spewed hundreds of thousands of tons of highly toxic substances such as lead, arsenic and cadmium, into the atmosphere and the communities that lived in its shadow.

This has been a game-changing week in the fight to end mountaintop removal. We will undoubtedly look back on the events of the past few days as a turning point in the struggle to end this incredibly destructive form of coal mining.

If you lived near a dump site where the hazardous waste was so toxic it could increase your cancer risk to as high as a staggering 1 in 50, wouldn't you want to know about it?

If the Obama administration allows hundreds of mountaintop-removal coal mining permits to go forward, it will result in the outright destruction of hundreds of miles of streams and forests in Appalachia.

Chevron's CEO, Dave O'Reilly, and I debated for an hour last night at the Commonwealth Club. We got to the bottom of some differences but didn't come to closure on some of the most important.

While many thought they were about to see a smackdown between Big Green and Big Oil, Chevron CEO Dave O'Reilly and Sierra Club Executive Director quickly struck a respectful tone.