A 33,000-year-old tooth found in Siberia offers new evidence about the prehistoric ancestry of man's best friend, according to a new study out Wednesday in a U.S. journal.

Dogs were already domesticated by the advent of agriculture, 10,000 years ago, but scientists still don't know how far back the history goes or just when and where the modern species we know as dogs became distinct from wild wolves.

The deep-space Herschel telescope, launched four years ago to observe the creation of stars, will soon be going out of service as its supply of instrument coolant runs out, the European Space Agency said on Tuesday.

When it was launched in May 2009, Herschel became the largest and most powerful infrared telescope in space and has made several discoveries, ranging "from starburst galaxies in the distant universe to newly forming planetary systems orbiting nearby young stars", the ESA said.

China will sharply boost renewable energy this year, it said Tuesday, after repeated bouts of heavy pollution across much of the country heightened public anger on the issue over recent weeks.

The country plans to increase hydropower generating capacity by 21 million kilowatts this year, wind by 18 million kilowatts and solar energy by 10 million kilowatts, the National Development and Reform Commission said in a report.

Millions of people in western India are suffering their worst drought in more than four decades, with critics blaming official ineptitude and corruption for exacerbating the natural water shortage.

Central areas of Maharashtra state, of which Mumbai is the capital, are facing a water shortage worse than the severe drought in 1972, the state's chief minister Prithviraj Chavan told Agence France Presse.

New U.S. government figures show the amount of heat-trapping carbon dioxide in the air jumped dramatically in 2012, making it very unlikely that global warming can be limited to another 2 degrees (1.2 C). Many governments set a 2-degree increase as the upper limit.

Scientists say the rise in CO2 reflects the global economy revving up and burning more fossil fuels, especially in China.

Ancient, mummified camel bones dug from the tundra confirm that the animals now synonymous with the arid sands of Arabia actually developed in subfreezing forests in what is now Canada's High Arctic, a scientist said Tuesday.

About 3.5 million years ago, Strathcona Fiord on Ellesmere Island's west-central coast would have looked more like a northern forest than an Arctic landscape, said paleobotanist Natalia Rybczynski of the Canadian Museum of Nature in Ottawa.

A recently discovered comet is closer than it's ever been to Earth, and stargazers in the Northern Hemisphere finally get to see it.

Called Pan-STARRS, the comet is passing within 100 million miles (160. million kilometers) of Earth on Tuesday, its closest approach. The ice ball will get even nearer the sun this weekend — just 28 million miles (45 million kilometers) from the sun. That's within the orbit of Mercury.

Eighty percent of sewage in India is untreated and flows directly into the nation's rivers, polluting the main sources of drinking water, a study by an environment watchdog showed Tuesday.

Indian cities produce nearly 40,000 million liters of sewage every day and barely 20 percent of it is treated, according to "Excreta Does Matter", a new report released by the Center for Science and Environment (CSE).

Israel is on a locust alert as swarms of the destructive bugs descend on neighboring Egypt ahead of the Passover holiday.

Israel's Agriculture Ministry set up an emergency hotline Monday and is asking Israelis to be vigilant in reporting locust sightings to prevent an outbreak.

A privately-owned unmanned U.S. space capsule docked Sunday at the International Space Station bringing food, scientific materials and crucial equipment to the space outpost.

NASA said that SpaceX's Dragon capsule linked up with the ISS's Harmony module at 8:56 am (1356 GMT).