Fifty years of rising crop yields has helped feed a hungry world. It also appears to have left its mark in more-intense seasonal swings in CO2 that land-based ecosystems take up, then return to the atmosphere.
Scientists, policymakers, and activists been holding out hope that an increase in extreme weather events might prompt Americans to embrace policies that curb greenhouse-gas emissions. They may be waiting a long time, a new study suggests.
Sajal Biswas, a snake charmer, puts the head of a snake into his mouth as he performs on a roadside on the outskirts of Agartala, capital of India's northeastern state of Tripura. He earns around 400 to 500 rupees ($6.45 to $8.07) per day.
For 57 hours in mid November, a squat lander with spindly legs made history as the first spacecraft to visit the nucleus of a comet – sending a wealth of information on the object to solar-system scientists back on Earth.
Marine ecologists have been witnessing mass mortality of starfish along the Northeast Pacific coast, and a team of scientists now believes they have identified the degenerative disease behind their deaths.
The European Space Agency's Philae lander has ended its brief, historic mission to the surface of a comet, giving scientists an unprecedented look at the structure and composition of a comet's nucleus.