Wind power: Clean energy, dirty business?

GDP grew 2.8 percent last quarter, but momentum still weak

12:24 pm ET - The fourth quarter 2.8 percent GDP increase represents a pickup from the 1.8 percent pace seen in the prior quarter, but it was lower than economists expected. And unemployment remains high.

Can California change US cars forever? New zero-emissions rules take aim.

7:23 pm ET - California has adopted new rules that require 15 percent of all cars sold in the state to be electric, plug-in hybrid, or hydrogen-powered by 2025. Perhaps surprisingly, automakers are onboard.

Utah school bomb plot: from inspiration to prevention, Columbine had a part

5:15 pm ET - One suspect in the Utah high school bomb plot interviewed the Columbine principal in December. Police were tipped off by a friend of the suspect who received a suspicious message. 

Syria's opposition concerned about independent armed rebel groups

2:55 pm ET - A member of the opposition's Syrian National Council told reporters in Paris that the council is concerned about the increasingly militarized rebel groups taking matters into their own hands. 

Anti-nuclear movement growing in Asia

1:33 pm ET - Though nuclear power still has a strong foothold in Asia, anti-nuclear sentiment and protest are growing from Mongolia to South Korea to Taiwan and even - in modest ways - in China.

Can economy help Obama reelection? One statistic gives him hope.

6:01 pm ET - Since 1948 only one incumbent president has won reelection with joblessness over 7 percent. There is another unemployment statistic, however, that could play in President Obama's favor.

How Pentagon budget cuts will reshape the Army

4:48 pm ET - The Army has been seen as one of the big losers in the Pentagon budget cuts released Thursday. But Army officials say now is the perfect time for the force to recast itself. 

• Pentagon budget: top 3 winners and losers

Obama outlines plan to cut college costs. Could it backfire on students? (+video)

12:48 pm ET - President Obama Friday made a set of bold proposals tying federal aid to colleges tuition costs. Most of Obama’s ideas would require approval from Congress – difficult to do in a polarized Washington.

Experts cast doubt on Japan nuclear power plant stress tests

10:36 am ET - The Japanese government ordered tests on all nuclear reactors after Fukushima meltdown, and are set to reopen at least one shortly, but advisers say the tests do not prove the plants are safe. 

Iran is gearing up for elections and it isn't pretty

12:20 pm ET - The arrest of at least 10 reporters since the turn of the year and new Internet restrictions point to a battening down of social control ahead of Iran's March elections.

What if we could predict tornadoes a month out? Scientists make strides.

12:14 pm ET - Scientists have only a fledging ability now, but a new approach to prediction could eventually allow forecasters to identify portions of states facing high risk for tornadoes in an upcoming month.

A confident Romney zings Gingrich in Republican debate No. 19 (+video)

8:58 am ET - MItt Romney was ready to answer questions about his wealth and to rebut rival Newt Gingrich during Thursday's Republican debate, the last before the Florida primary on Tuesday.

• Vox News: Mitt Romney, the first Mexican-American president?

Russia bars liberal candidate from presidential election

10:55 am ET - Russia's electoral commission has disqualified veteran liberal politician Grigory Yavlinsky from running against Vladimir Putin, showing that Putin's 'managed democracy' is still at work.