An activist caravan to bring one of Jimmy Carter’s solar panels back to the White House symbolizes the time that the U.S. has lost in developing new energy technologies ”“ and the urgent need for taking action on climate.

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.

Coffee production has long been vulnerable to drought or excess rains. But recently, a tiny insect that thrives in warmer temperatures — the coffee berry borer — has been spreading steadily, devastating coffee plants in Africa, Latin America, and around the world.

Earlier this year, 38-year-old environmental activist Michael Brune was named the unlikely choice to take over as head of the Sierra Club, the largest U.S. conservation organization. In an interview with Yale Environment 360, Brune says it’s time to move beyond overly accommodating strategies like those that failed to win passage of U.S. climate legislation.

The Gulf of Mexico’s capacity to recover from previous environmental assaults — especially the 1979 Ixtoc explosion — provides encouragement about the prospects for its post-Deepwater future. But scientists remain worried about the BP spill's long-term effects on the health of the Gulf and its sea life.

As warming intensifies, scientists warn, the oxygen content of oceans across the planet could be more and more diminished, with serious consequences for the future of fish and other sea life.

Ample blame exists for the demise of climate legislation in the U.S. Senate, from President Obama’s lack of political courage, to the environmental community’s overly ambitious strategy, to Republican intransigence. A way forward exists, however, to build on the rubble of the Senate’s failure to cap carbon emissions.

Environmentalists in the U.S. are increasingly trying to use the Endangered Species Act to ease the impact of global warming on numerous animals and plants, including the American pika. The goal is not only to protect the habitat of at-risk species but also to force reductions in greenhouse gas emissions.

Unearthing photographs of the Himalaya dating back more than a century, mountaineer and filmmaker David Breashears has assembled a powerful visual record of the rapid retreat of the region’s glaciers. By comparing archival photographs from such renowned explorers as George Mallory to photographs taken in the past three years, Breashears has documented the steady disappearance of these great rivers of ice, whose melting will eventually threaten the water supplies of hundreds of millions of people across Asia.

The polar bear has long been a symbol of the damage wrought by global warming, but now biologist Andrew Derocher and his colleagues have calculated how long one southerly population can hold out. Their answer? No more than a few decades, as the bears’ decline closely tracks that of the Arctic’s disappearing sea ice.

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.

In the wake of the failed Copenhagen summit, prospects for cutting global CO2 emissions are worse than they’ve been in years. With talk of mandated cuts now fading and with countries exploiting loopholes, the world appears headed toward a flawed agreement based not on science but on politics.

Even after the failure to reach agreement on binding CO2 cuts in Copenhagen last December, the United Nations’ outgoing chief climate negotiator is confident that the world is making progress on global warming. The key, he says, is convincing all nations, particularly developing ones, that tackling climate change is in their long-term economic interest.

For years, free-market fundamentalists opposed to government regulation have sought to create doubt in the public’s mind about the dangers of smoking, acid rain, and ozone depletion. Now they have turned those same tactics on the issue of global warming and on climate scientists, with significant success.

As global warming intensifies, demands for human manipulation of the climate system are likely to grow. But carrying out geoengineering plans could prove daunting, as conflicts erupt over the unintended regional consequences of climate intervention and over who is entitled to deploy climate-altering technologies.

Within the planet’s oceans and soils are trillions of bacteria that store and release far more carbon dioxide than all of the Earth’s trees and plants. Now, scientists are attempting to understand how the world’s bacteria will influence — and be influenced by — a warming climate.

The tropical forest conservation plan, known as REDD, has the potential to significantly reduce deforestation and carbon dioxide emissions worldwide. But unless projects are carefully designed and monitored, the program could be undercut by shady dealings at all levels, from the forests to global carbon markets.

Environmentalist David Orr says the easy part of helping the United States live within its ecological limits may be passing laws, such as one that puts a price on carbon. The hard part, he maintains in an interview with Yale Environment 360, is changing a culture of consumption that causes extensive environmental damage — and unhappiness.

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?

Is human activity altering the planet on a scale comparable to major geological events of the past? Scientists are now considering whether to officially designate a new geological epoch to reflect the changes that homo sapiens have wrought: the Anthropocene.

The oil slick spreading across the Gulf of Mexico has shattered the notion that offshore drilling had become safe. A close look at the accident shows that lax federal oversight, complacency by BP and the other companies involved, and the complexities of drilling a mile deep all combined to create the perfect environmental storm.