Among the many measures the world can take to wean itself off fossil fuels, few match the benefits of making homes, business, and cars more energy-efficient. But financial and psychological barriers have kept individuals, businesses, and governments from realizing efficiency’s great potential.

A decade ago, Nobel Prize-winning scientist Paul Crutzen first suggested we were living in the “Anthropocene,” a new geological epoch in which humans had altered the planet. Now, in an article for Yale Environment 360, Crutzen and a coauthor explain why adopting this term could help transform the perception of our role as stewards of the Earth.

Forecasting what the Earth’s climate might look like a century from now has long presented a huge challenge to climate scientists. But better understanding of the climate system, improved observations of the current climate, and rapidly improving computing power are slowly leading to more reliable methods.

As head of a new energy office at the Pentagon, Sharon Burke is charged with finding ways for the U.S. armed forces to cut its dangerous reliance on oil. In an interview with Yale Environment 360, she talks about what new technologies are being tested and why the military considers energy use a key strategic issue in the field.

While the collapse of climate legislation in Congress was a setback for some green businesses, many others are moving ahead with projects to develop renewable energy. One major reason: The clean-tech sector is rapidly growing worldwide, and U.S. companies don’t want to be left behind.

By year’s end, regulators are expected to approve a host of solar energy projects in California that could eventually produce as much electricity as several nuclear plants. In an interview with Yale Environment 360, John Woolard, the CEO of the company that has begun construction on the world’s largest solar-thermal project, discusses the promise — and challenges — of this green energy boom.

Will electric cars one day become part of a network of rechargeable batteries that can help smooth out the intermittent nature of wind and solar power? Many experts believe so, pointing to programs in Europe and the U.S. that demonstrate the promise of vehicle-to-grid technology.

The U.S. has invested billions of dollars trying to create a controlled form of nuclear fusion that could be the energy source for an endless supply of electricity. But as a federal laboratory prepares for a key test, major questions remain about pulling off this long-dreamed-of technological feat.

As climate scientists wrestle with the complexities of how the planet will react to rising greenhouse-gas levels, no variable is more difficult to decipher than the impact of clouds. But thanks to new satellite data and other technologies, clues are emerging that may help solve the puzzle.

Consumers now have little information about the true ecological impacts of what they buy. But that may be about to change, as new technologies that track supply chains are emerging and companies as diverse as Unilever and Google look to make their products more sustainable.

New technologies, feed-in tariffs, and tax credits are helping propel the small wind industry, especially in the United States. Once found mostly in rural areas, small wind installations are now starting to pop up on urban rooftops.

The surest sign of a warming Earth is the steady melting of its ice zones, from disappearing sea ice in the Arctic to shrinking glaciers worldwide. Now, scientists are using increasingly sophisticated satellite technology to measure the extent, thickness, and height of ice, assembling an essential picture of a planet in transition.

As utilities seek to build new nuclear power plants in the U.S. and around the world, the latest generation of reactors feature improvements over older technologies. But even as attention focuses on nuclear as an alternative to fossil fuels, questions remain about whether the newer reactors are sufficiently foolproof to be adopted on a large scale.

Flying dwarfs any other individual activity in terms of carbon emissions, yet more and more people are traveling by air. With no quick technological fix on the horizon, what alternatives — from high-speed trains to advanced videoconferencing — can cut back the amount we fly?

The practice of “commissioning,” in which an engineer monitors the efficiency of a building from its design through its initial operation, just may be the most effective strategy for reducing long-term energy usage, costs, and greenhouse gas emissions from buildings. So why is it so seldom used?

California’s high-tech giants have long used renewable energy to help power their Silicon Valley headquarters. Now, companies such as Google, Adobe Systems, and eBay are preparing for the next step — investing in off-site solar and wind installations and innovative technologies that will supply their offices and data centers with green electricity.

Our high-tech products increasingly make use of rare metals, and mining those resources can have devastating environmental consequences. But if we block projects like the proposed Pebble Mine in Alaska, are we simply forcing mining activity to other parts of the world where protections may be far weaker?

Two billion people worldwide do their cooking on open fires, producing sooty pollution that shortens millions of lives and exacerbates global warming. If widely adopted, a new generation of inexpensive, durable cook stoves could go a long way toward alleviating this problem.

After making his fortune with Idealab and a host of technology start-ups, Bill Gross has turned his attention to renewable energy. In an interview with Yale Environment 360, Gross talks about the solar power plant technology his company eSolar is developing and about the future of solar.

The drive to extract and store CO2 from coal-fired power plants is gaining momentum, with the Obama administration backing the technology and the world’s first capture and sequestration project now operating in the U.S. Two questions loom: Will carbon capture and storage be affordable? And will it be safe?

For years, the promise and hype surrounding electric cars failed to materialize. But as this year’s Detroit auto show demonstrated, major car companies and well-funded startups — fueled by federal clean-energy funding and rapid improvement in lithium-ion batteries — are now producing electric vehicles that will soon be in showrooms.