As many as 40,000 protesters from 30 states descended on the White House on Sunday and demanded that President Obama kill the proposed Keystone XL oil sands pipeline. By the estimates of organizers, it was the biggest protest march for climate change action in the nation's history.

In about 18 cities from Boston to Los Angeles, thousands more participated in solidarity rallies—and helped garner unusual nationwide media attention for an issue that has typically slipped under the local media radar.

Mitt Romney has vowed to drill the nation's way out of its foreign oil addiction instead of investing in clean fuel technologies—but according to Dan Senor, one of Romney's closest political advisers, that's bad economics.

Senor's 2009 bestseller, "Start-Up Nation: The Story of Israel's Economic Miracle," argues that economies geared toward advancing and adopting new technologies like oil-free cars will transform entire global industries. He says economies focused on traditional oil drilling will continue to generate short-term wealth, but at the cost of innovation.

"You look at some of these countries in the Arab world that are so dependent on oil ... They're being held back by so little innovation in those sectors," Senor said last year in a lecture at the University of Rochester. "The real economic growth is coming in biotech, medical devices, cleantech, greentech, IT."

Senor's argument calls into question the Romney campaign's claim that developing all U.S. carbon energy reserves would spawn an economic resurgence.

Editor's note: This version of the story adds comment from Koch Industries.

Rep. Henry Waxman (D-Calif.) today renewed his request that the House Committee on Energy and Commerce investigate the role of Koch Industries in the Keystone XL pipeline.

Waxman, the ranking minority member of the committee, made his request in a letter to committee chairmen Fred Upton (R-Mich.) and Ed Whitfield (R-Ky.).

Waxman first asked for an investigation in May, when the committee was holding hearings on the Keystone XL, a controversial Canada-to-Texas oil pipeline that would allow as much as 830,000 barrels a day of a particularly dirty form of oil, locked up in Alberta's tar sands, to reach refineries in the Gulf of Mexico.

The controversy over the Kochs and the pipeline was sparked by an InsideClimate News report from February. That analysis, also published on Reuters.com and later cited by various news organizations, found that Koch Industries is deeply involved in the Canadian oil sands trade and is well positioned to benefit if more heavy crude is exported to the United States. The company denied the report, and Waxman subsequently made his own inquiries.

"When I first raised this issue in May, representatives from Koch denied any interest in the pipeline and Chairman Upton called the idea that there could be a link between Koch and the pipeline an 'outrageous accusation' and a 'blatant political sideshow,'" Waxman wrote in his letter. "Recently, however, I have become aware of evidence that appears to contradict the assertions of the Koch representatives and Chairman Upton."

Waxman cites legal papers that a Koch Industries subsidiary, called Flint Hills Resources Canada LP, filed with the Canadian government, recently uncovered by InsideClimate News, in which the company claimed "a direct and substantial interest" in the Keystone XL.

In recent months Koch Industries Inc., the business conglomerate run by billionaire brothers Charles and David Koch, has repeatedly told a U.S. Congressional committee and the news media that the proposed Keystone XL oil sands pipeline has "nothing to do with any of our businesses."

But the company has told Canadian energy regulators a different story.

In 2009, Flint Hills Resources Canada LP, an Alberta-based subsidiary of Koch Industries, applied for—and won—"intervenor status" in the National Energy Board hearings that led to Canada's 2010 approval of its 327-mile portion of the pipeline. The controversial project would carry heavy crude 1,700 miles from Alberta to the Texas Gulf Coast.

In the form it submitted to the Energy Board, Flint Hills wrote that it "is among Canada's largest crude oil purchasers, shippers and exporters. Consequently, Flint Hills has a direct and substantial interest in the application" for the pipeline under consideration.

To be approved as an intervenor, Flint Hills had to have some degree of "business interest" in Keystone XL, Carole Léger-Kubeczek, a National Energy Board spokeswoman, told InsideClimate News. Intervenors are granted the highest level of access in hearings, with the option to ask questions. The Energy Board approved Canada's segment of the pipeline with little opposition, and Flint Hills did not exercise its right to speak.

With reporting by Elizabeth McGowan

With the oil industry under the national spotlight, environmental advocates are pointing to a pair of recent oil spills to bolster their campaign against a much-disputed Alberta-to-Texas tar sands pipeline that could win U.S. approval by the end of the year.

When an Ecuadorian judge ordered Chevron to pay plaintiffs $8.6 billion last month for damages from oil contamination in the Amazon jungle after 18 years in the courts, environmental and indigenous people's advocates were euphoric.

Some hoped the time had finally come for larger environmental judgments against oil majors, widely derided for not paying the full costs connected to their oil spills.

But their hopes are fading. International arbiters at the Hague, Netherlands and a U.S. District Court in New York have separately blocked enforcement of the verdict. On March 11, Chevron appealed the Ecuador ruling. The appeals process could drag on for years, during which time no payment can flow.

The case is especially complex — it marks the first time a U.S. oil giant was held accountable in a foreign court for pollution overseas. But it raises a fundamental question about all court orders forcing energy companies to pay for spill cleanup and damages: Are they working?

The short answer is not as much, or as fast, as many would like.

A look at some of the biggest oil spills over the last three decades that led to litigation shows that most energy firms pay partial rewards but very few, if any, environmental damages; outcomes vary with no apparent rhyme or reason; and cases, which follow appeal after appeal, can take decades to litigate.

When the global financial crisis rippled through economies around the world in 2008, experts warned that global warming would slide down on the list of the world's priorities. In part, they were right.

Trillions flowed to resuscitate teetering economies, which were based on fossil fuels. Money pledged to address climate change was never mobilized.

But something else happened at the same time: Many nations' fiscal-stimulus packages included billions to finance clean energy projects.

No nation was as bullish on the idea as South Korea. Asia's fourth-largest economy poured 80 percent of its $38 billion stimulus program into what it calls "green growth." Later, it committed 2 percent of its annual GDP over five years to the same national cause.

Now, both rich and poor nations are turning to Seoul for lessons in green-powered development, and the new economic approach that was born out of financial mayhem. 

Could it take hold?

Without a global carbon price, the expanding shale gas boom would exacerbate climate change and take money away from renewable energy projects, a new report said, calling for a worldwide pause until countries take steps necessary to lower the risks of the new wave of drilling.

The rapid surge in staple food prices in 2008 that sparked global riots and sent millions into poverty is back. Now, researchers say that because of global warming and trends in population, these dramatic price movements in the food economy are likely here to stay.

The influential Worldwatch Institute, based in Washington, D.C.,  gave warning last week that if current trends continue, extraordinary weather events like last year's Russian heatwave that wiped out 40 percent of the nation's wheat crop will recur more frequently, with effects felt everywhere and especially in the world's poorest regions.

"The frontlines of this crisis are occupied by the world's 925 million undernourished people," the group said in its annual State of the World report.

The Obama administration put off for another three years a decision on whether to regulate planet-warming gases from biomass power. The surprise delay dealt a blow to green groups' hopes for pollution controls on wood-burning incinerators anytime soon, while industry breathed sighs of relief.

"It was a total shock," said Margaret Sheehan, a lawyer with the Cambridge, Mass.-based Biomass Accountability Project, who said that she believes Big Timber was behind the U.S. EPA's decision.

Dan Whiting, spokesperson for the National Alliance for Forest Owners (NAFO), an organization of private forest owners in 47 states, said he was "pleasantly surprised."

Still, the delay leaves wide open a question central to the industry's future: Should turning tree parts into electricity qualify as clean renewable power in the eyes of government regulators, or should biomass emissions be regarded as a source of greenhouse gas pollution?