The Keystone XL pipeline is a threat to our nation. It would increase pollution and intensify climate change for generations to come. We must raise our voices and demand our leaders reject this dirty scheme.

I was in college when tens of thousands of people marched on Washington for the first Earth Day. Raw sewage floated in rivers and clouds of smog hung over cities. But then something amazing happened. People spoke out. Thousands of students, workers, and ordinary citizens used their voices to say, 'This has to change.'

The science tells us that if we fail to reduce global warming pollution, global temperatures will rise to dangerous levels and unleash devastating extreme weather events and accelerate destructive sea level rise.

Protecting eagles from the threat of extinction is a conservation success story that we must prudently safeguard for future generations to come.

Every year, tens of millions of salmon return to the pristine shores of Bristol Bay in Alaska. They linger in the bay's cool, shallow waters before charging up nearby streams to spawn and create another generation of wild salmon.

The San Gabriel Mountains rise like a rampart at the edge of the city, safeguarding more than 500,000 acres of mature forests, mountain streams, dramatic waterfalls, and towering peaks that reach over 9,000 feet. These untamed places attract bighorn sheep, mountain lions, and other threatened or endangered species.

A stock market index helps investors track the performance of a group of stocks. NRDC worked with FTSE to develop comprehensive and transparent methodologies that screen out companies linked to owning, exploring, or extracting fossil fuels.

We look back at the 1990 Clean Air Act amendments, where people screamed and hollered it's going to be too expensive, they couldn't afford it, and it wouldn't work. And it worked. It worked faster than people expected, at much less cost.

For decades, NRDC has created and supported policies that will ultimately end our reliance on fossil fuels.

Under pressure from a growing movement of people who want their money out of fossil fuels, universities, pension investors and foundations are looking to exclude coal, oil and gas stocks from their portfolios.

All Americans have benefited from the dedicated service of Representative Henry Waxman. In every battle and in every moment that mattered most, Rep. Waxman stood up for the air we breathe, the water we drink, and the wild places we cherish.

Striking a balance between wildlife conservation and wind energy development starts with understanding threats to eagle populations and how our actions, including operating wind farms, are affecting them.

Though many corporations honor commitments to reduce dangerous pollution, some cut corners and cheat. The marketplace doesn't always have mechanisms to correct bad actors.

I have been fighting climate change for two decades, and people often ask me how I remain hopeful in the face of extreme weather and grim forecasts. The answer is simple: I see countless solutions spreading across the nation and across the world. But we need more investment.

In the end, the market will decide which is the better performer: dirty coal-fired power or clean wind and solar. Market-based competition. That doesn't sound like communism to me.

VW has held a beloved place in American culture. When I graduated from college, many of my friends drove across the country, and most hit the road in a VW van or Bug. Through the years, these cars have represented youth, freedom and quirkiness.

I have visited people whose health has been endangered by tar sands oil. I have watched neighbors struggle to recover from Superstorm Sandy. I have seen solar panels and wind turbines become an increasingly familiar part of the landscape.

The fossil fuel industry commands outsize sway over U.S. politics, markets, and democracy. I knew these companies were formidable, but when I served on the National Commission on the BP Deepwater Horizon Oil Spill and Offshore Drilling, I got a close up view of how the industry disregards government safeguards.

Americans are already paying the price for record heat waves, dirty air, and an unstable climate. We need to fight these threats with every weapon we have, and the electricity industry has to do its fair share.

I attended the climate talks in Copenhagen in 2009, and back then, national governments waited until days before to submit climate plans, and the U.S. based its pledge on a proposed bill that would fail in the Senate.

I have long understood that climate change is not only an environmental issue - it is a humanitarian, economic, health, and justice issue as well.

Pollution from oil and gas development, toxic runoff, and miles and miles of plastic trash foul the waters and threaten marine life.

The oceans produce up to 70 percent of our oxygen, they shape our climate, and they support an American oceans economy larger than our nation's entire agriculture sector.

Studies show that women are more likely than men to die in natural disasters. Women's voices must be heard.

As heat rises, so does the number of people trying to cool down homes, schools, hospitals and businesses. This isn't just about comfort; it's a matter of public health.

A cap on carbon is important because it sets a specific goal for reducing carbon emissions 80% by 2050.

Mercury is a potent toxin that interferes with the human nervous system. Reducing this hazard will be a major public health breakthrough.

Whether it is salt farmers in India embracing solar power or wind companies creating tens of thousands of jobs in America, people are providing a vision for the clean energy future.

Countries have made impressive pledges to cut carbon pollution, but we have to ensure these promises become actions.

Though every nation must do its part to address climate change, developed nations are responsible for the lion's share of carbon pollution in the atmosphere, and they have an obligation to help developing nations transition to a sustainable future.

Putting a tax on carbon could be an effective approach for curbing global warming pollution.

Too often, the air conditioners we use to cool down also contribute to climate change - the very force that's fueling extreme heat.

Shell Oil's decision to pull the plug on drilling for oil in the Chukchi Sea is a major victory for the Arctic.

Our nation has abundant clean energy resources, and tapping them will generate jobs, make the air safer to breathe, and tackle climate change - the greatest environmental crisis of our time.

When climate change supercharges weather patterns, the disadvantaged often suffer first and most.

Instead of going to the ends of the Earth - and plumbing the depths of the oceans - to squeeze out every last drop of oil, we need, instead, to do everything we can to reduce the risks of offshore oil and gas production.

Business leaders, social justice groups, farmers and ranchers, doctors and nurses and people from all walks of life are concerned about the climate threat.

Climate change deniers would have us believe that oil, gas, and coal are the only ways to power a modern, industrialized society. They are wrong, and the proof is all around us.

Strong limits on carbon pollution will save Americans money, create jobs, improve our health, and help defuse climate change.

Tar sands oil is the dirtiest fuel on Earth. Because producing it consumes so much energy, a gallon of tar sands crude generates 17 percent more carbon pollution than conventional crude oil.

Green roofs, roadside plantings, porous pavement, and sidewalk gardens have been proven to reduce flooding. They absorb rainwater before it swamps the streets and sewage systems.

New York and Connecticut belong to the Regional Greenhouse Gas Initiative to cut carbon emissions, and New York City has been a leader in energy efficiency.

We'll always need energy. We need to communicate, too, but we're not stuck with hand gestures and smoke signals. There are better ways to power our future than by digging fossil fuel from the ground and setting it on fire.

Healthy forests and wetlands stand sentry against the dangers of climate change, absorbing carbon dioxide from the atmosphere and locking it away in plants, root systems and soil.

The U.S. can become carbon neutral in our lifetimes. In the process, we will put millions of Americans to work, make our companies more competitive, and shield our communities from extreme weather. And we will honor our obligation to leave the world a better place for future generations.

Los Angeles County is one of the most park-poor urban areas in the nation, and the San Gabriel Valley - stretching from Pasadena to Pomona - is especially starved for open space.

Declaring the San Gabriel Mountains a national monument will make this natural wonder more accessible. It will welcome people from all walks of life and maintain the mountains' wild character at the same time.

Nearly every president in the past 100 years has declared national monuments, from Teddy Roosevelt creating the Grand Canyon National Monument to George W. Bush preserving 10 islands and 140,000 square miles of ocean waters in the Northwestern Hawaiian Islands.

The San Gabriel monument expands our natural heritage, but there is more in need of safeguarding - extraordinary places like Utah's Greater Canyonlands.

The San Gabriel Valley, stretching from Pasadena to Pomona, is especially starved for open space. The valley has a rich array of ethnically diverse communities, but it also has some of the highest rates of childhood obesity and diabetes in the state.