These large-scale engineering plans include the world's tallest building and a manmade river that dwarfs the Nile.
Satellite observations of the Earth's magnetic field reveal a fast-moving stream of metal deep inside the planet.
Developing countries in particular are able to sell solar power for half the cost or generating electricity from coal.
Methane is many times more potent than carbon dioxide, but it's also more difficult to capture.
Despite seemingly contradictory findings, here's the current state of climate change.
Concerns grow that in a new presidential administration, politics will hinder scientific research.
Machines could make fields more productive and solve farm labor shortage.
The green space would be 12 times the size of New York's Central Park and includes a thousand-acre hardwood forest.
Green building designs incorporate trees and plants into urban rooftops and even skyscraper walls.
The largest source of renewable energy in the U.S. generates millions of tons of the potent greenhouse gas.