A leading environmentalist explains why drastically reducing carbon dioxide emissions now will be easier, cheaper, and more ethical than dealing with runaway climate destabilization later.

The days of freely dumping greenhouse gases into the atmosphere are coming to an end, but how best to price carbon emissions remains in dispute. As the U.S. Congress debates the issue, Yale Environment 360 asked eight experts to discuss the merits of a cap-and-trade system versus a carbon tax.

The scrubby jatropha tree has been touted as a wonder biofuel with unlimited potential. But questions are now emerging as to whether widespread jatropha cultivation is really feasible or whether it will simply displace badly-needed food crops in the developing world.

For spurring the transformation to a low-carbon economy, the federal and state governments, universities, and the private sector must join together to create a network of energy research institutes that could speed development of everything from advanced batteries to biofuels.

New solar thermal technology overcomes a major challenge facing solar power: how to store the sun’s heat for use at night or on a rainy day. As researchers tout its promise, solar thermal plants are under construction or planned from Spain to Australia to the American Southwest.

In an interview with Yale Environment 360, Bill McKibben explains why he’s now focused on organizing a citizens movement around climate change — and why he believes this effort is critical for spurring world leaders into action.

Mostly conceived by international architects, China’s eco-cities were intended to be models of green urban design. But the planning was done with little awareness of how local people lived, and the much-touted projects have largely been scrapped.

The economic downturn need not halt the development of green energy. In fact, with renewable technologies improving dramatically and new U.S. policies emerging, continued progress toward an energy revolution is inevitable.

The number of vehicles worldwide is expected to reach two billion in the next two decades. Surprisingly, China where the demand for cars has been skyrocketing just may offer the best hope of creating a new, greener transportation model.

Yale University’s recently opened Kroon Hall is a state-of-the-art model of where the green building movement is headed. Yet even this showcase for renewable energy highlights the difficulties of creating a building that is 100 percent carbon neutral.

Secretary of State Hillary Clinton’s trip to China could be the first step in forging a partnership between the world’s largest emitters of greenhouse gases. A leading China expert sets forth a blueprint for how the U.S. and China can slow global warming and strengthen their crucial relationship.

Issued less than two years ago, the report from the Intergovernmental Panel on Climate Change was a voluminous and impressive document. Yet key portions of the report are already out of date, as evidence shows the impacts of warming intensifying from the Arctic to Antarctica.

In the last few decades, urban sprawl, once regarded as largely a U.S. phenomenon, has spread across Europe. Now an emerging group of planners is promoting a new kind of development — mixed-use, low-carbon communities that are pedestrian-friendly and mass-transit-oriented.

Many environmentalists assume that putting a price on carbon and creating a renewable energy economy will require major public sacrifice. But the Sierra Club’s Carl Pope argues that a well-designed package of market reforms — not austerity — will lead to a prosperous, low-carbon future.

Europe’s backpedaling last month on toughening its carbon trading system may have signaled the end of its leadership on climate change. Now, with a new administration and Congress, America appears ready to commit itself to tackling global warming.

A number of companies, including one headed by biologist and entrepreneur Craig Venter, are developing genetically engineered biofuels that they say will provide a greener alternative to oil. But some environmentalists are far from convinced.

The potential for electric vehicles has been talked about for decades. But a former Israeli software entrepreneur is developing a game-changing infrastructure that could finally make them feasible — a standardized network of charging stations where drivers can plug right in.

Environmentalists from Bill McKibben and Paul Hawken, to Fred Krupp and Frances Beinecke offer President Obama their advice on the priorities he should set for the first 100 days of his administration.

Despite daunting challenges, technology to harness the power of the waves and tides is now being deployed around the world from Portugal to South Korea to New York’s East River. These projects, just beginning to produce electricity, are on the cutting edge of renewable energy’s latest frontier: hydrodynamic power.

In an interview with Yale Environment 360, Amory Lovins, co-founder and chairman of Rocky Mountain Institute, says that world's biggest untapped energy source is efficiency. And retooling for energy efficiency will require "barrier-busting" at many levels. And government, Lovins says, "should steer, not row."

Any federal assistance package for U.S. automakers must require that they finally commit to retooling their industry to produce cleaner, more fuel-efficient cars.