Carbon logic dictates that if President Obama is at all serious about addressing climate change, he must help put an end to Canada's tar sands folly, and say no to the Keystone XL pipeline.

Leaders of the world's governments made a commitment to us more than 20 years ago. They...

As a small team of youth ambassadors for Greenpeace's Arctic campaign begin their trek to the North Pole, I'm reminded of the campaign to save the Antarctic (video), which I led on behalf of Greenpeace in the 1980s.

While politics between the two poles are literally...

A report published today by Europe's Health and Environment Alliance (HEAL) is a powerful wake-up call about the dangers of coal-fired power. The Unpaid Health Bill: How Coal Power Plants Make Us Sick claims to provide the "first ever economic assessment of the health costs associated with air...

Alberta's tar sands lobbyists must be earning a fortune these days.

So much dirty oil, and so few pathways to market. Their opponents have successfully blocked several of those pathways for the time being, forcing the beleaguered Canadian province to fight a battle on multiple fronts. And those who think...

"What gives you hope? This is a question I'm often asked these days. And what I've come to realize is that being hopeful, in the face of so much bad news about climate change, is not something that just happens -- at least not to me. It's not a passive...

There's a sign hanging at Muir Woods, a gorgeous redwood forest not far from San Francisco, which reads:

"In 1945, delegates from all over the world met in San Francisco to establish the United Nations. On May 19, they traveled to Muir Woods to honor the memory of President Franklin...

Like the Ghost of Christmas Future, the World Bank has just provided us with a frightening glimpse into our world-to-be if, unlike Scrooge, we fail to change our ways.

The year is 2100. Governments have failed to heed the increasingly urgent warnings 100 years back to drastically reduce CO2 emissions...

Europe may not be dealing with freak weather events at the moment, but in economic and social terms the storm clouds over the continent have become a permanent feature on the landscape -- for at least the past three years now -- and the hard rain is now falling, in...

Superstorm Sandy changed the U.S. political zeitgeist on climate change virtually overnight. When BusinessWeek runs a cover blazoned with "It's Global Warming Stupid" and politicians start breaking their "climate silence," you know the jig is up. President Obama acknowledged as much in his acceptance speech, when he said he wanted...

As I write this, President Obama and Governor Romney are preparing for their final pre-election debate in Boca Raton. Though Governor Romney has used climate change as joke material, it is no laughing matter in Florida, a place that has been called "ground zero when it comes...

There are no technological barriers to staving off a climate crisis. So what's really holding us back?

I've recently returned home after two weeks of intensive meetings, workshops and speaking engagements in the U.S., where this question was at the heart of virtually every conversation.

The most obvious answer,...

I'm notoriously bad at remembering jokes, but the reaction to last week's announcement that Japan would phase-out nuclear power by 2040 reminded me of this one:

Three guys are stranded on a deserted island. They've been there for years; their clothes are shredded and hanging from their emaciated...

Twice in recent months, I've heard speakers refer to a decisive moment in American history, a moment which shows our capacity to mobilize quickly in the face of an existential threat. One of them was Lester Brown, who wrote in his book Plan B 2.0: Rescuing a Planet...

Todd Stern, the U.S. Special Envoy for Climate Change, was in my neck of the woods the other day. Speaking at Dartmouth College, an hour's drive from where I'm spending a quiet vacation with my family, he said something so disturbing that I was compelled to dust the beach sand...

"Words Failed Us" read the Greenpeace banner on Nelson's Column at the close of the Rio Earth Summit. No, not the one that just ended, but the one 20 years ago, which by comparison seems like the golden age of multilateralism in action.

It would take a brave soul to stand in front of one of the largest and most important gatherings the United Nations has ever held and ask this question:

Are you here to 'save face' or to save us?

And indeed she was brave. One bright 17-year old girl from...

Reading the latest edition of UNEP's Global Environmental Outlook (PDF) last week was enough to make me lose the will to live.

It was sad to read what we all intuitively know: "The world continues to speed down an unsustainable path despite over 500 internationally agreed goals and...

Watching the climate negotiations in Bonn last week, I had an unsettling sense of déjà vu. Large conference room, familiar faces, and the same basic conundrums that derailed Copenhagen, complicated Cancun, and got papered over in Durban. Let's face it, the climate negotiations have become a Gordian knot awaiting the...

When the chief economist for the International Energy Agency (IEA) issues a dire warning, you'd think the world's leaders would sit up and take notice. If this statement by Fatih Birol last week wasn't a dire warning, then I don't know what is: "What I see now with...

Dear Presidents and Prime Ministers, Kings and Queens:

Once every generation or so, you're asked to step outside your national mindset and collectively figure out how to safeguard the planet and all its inhabitants. I grant you this: it's no easy task.