The massive energy bill that would set a cap on carbon dioxide emissions and provide other incentives and requirements for clean energy has passed the U.S. House of Representatives by a slim margin.

It's far from becoming law, though. Passing the bill in the Senate will be more difficult: many Democrats voted against the bill in the House, something that can't happen in the Senate if it is to pass. What's more, President Obama isn't entirely happy with the bill and will be pushing to get some changes made, including removing a provision designed to encourage other countries to set up emissions goals of their own, according to the Washington Post.

Some experts hope that the bill's passage in the House will prove a strong bargaining chip later this year when world leaders meet to discuss international caps on emissions.

The Washington Post reports today that the House Energy and Commerce Committee approved a bill that would establish a cap and trade system for limiting carbon dioxide emissions. A cap and trade system is a market-based approach designed to allow utilities and other major emitters of carbon dioxide to find the cheapest way to reduce their emission. It involves setting a cap on emissions and then issuing allowances to emitters. Many experts support auctioning off those credits, but the bill gives 85 percent of them away.

In a similar European cap-and-trade system, giving the allowances away seems to have led to windfall profits for utilities.

President Obama originally supported auctioning the allowances, and budget projections included revenue from such auctions. That money would have been used for clean-energy R&D, and for offsetting energy price increases causes by the cap on emissions.

The bill still faces several hurdles before becoming law. It may undergo review by other committees in the House before coming to the entire House for a vote. Then it has to get past the Senate, which has blocked cap-and trade bills in the past. This bill, however, has strong support from the Obama administration and, according to the Post, extra momentum because of the Energy and Commerce Committee's approval.

Yesterday, President Obama unveiled a strategic plan for developing high-speed rail in the United States. The trains, which would travel at least 90 miles per hour and as fast as 250 miles per hour, would be designed to replace cars and airplanes for trips between cities 100 to 600 miles apart. The plan includes a map of 10 potential routes, including a few in the Northeast and a system in the Midwest centered on Chicago. Which of these routes will get funding hasn't been decided yet. The economic stimulus plan included $8 billion for high-speed rail, and Obama's budget proposes an additional $1 billion in grants per year for five years.

Some of the money will be directed to projects that already have initial engineering and environmental work completed--projects improving existing rail to increase speeds from 70 miles per hour to over 100. But much of it won't be spent for years.

High-speed rail can reduce congestion, and it's more efficient than travel by car or plane. According to the White House, "Today's intercity passenger rail service consumes one-third less energy per passenger-mile than cars." New high-speed rail, which could be somewhat more efficient than today's trains, could reduce carbon dioxide emissions by six billion pounds of CO₂ a year. High-speed rail has been successful in France, Spain, and Japan, and it's growing rapidly in China. But passenger rail has limped along in the United States, especially outside of the Northeast. As Obama noted in a rousing speech in support of his plan, "Americans love their cars." Who knows if things will change if train speeds increase?

The high-speed rail projects won't necessarily use much new technology. One thing mentioned in the plan is something called Positive Train Control, a system for monitoring and controlling trains better. It would include advanced GPS tracking, using the Nationwide Differential Global Positioning System (NDGPS), and remote controls that can be used to stop the train if the driver has passed out. Not a bad idea for a train approaching an intersection at 220 miles per hour--the speed for a proposed rail system in California.