It's official: Congress' first agenda item, now that Republican control has begun, will be passing a bill to approve the Keystone XL pipeline. This maneuver failed late last year, but with Republicans now in control of the Senate, it's expected they can get a bill to the desk of the president - who has already said he'll veto it.

There may be many reasons to object to another Keystone vote - including the fact that the Keystone XL legislation singles out one company for special treatment - but perhaps the biggest objection is that it is really just a symbol.

For environmentalists, it symbolizes the increasingly urgent need to keep fossil fuels in the ground. For Republicans, it symbolizes everything they hate about how environmentalists seek to block industrial projects.

But when Congress focuses on symbols rather than substance, everybody loses. The truth is that building Keystone is not economically essential to the United States (sorry, Republicans), but stopping it is also not, in the view of many scientists, going to do a ton to save the climate (sorry, greens).

Either way, the last thing America actually needs is another Keystone debate. But there are really helpful things Congress could be doing instead to protect the environment and boost the economy. Here are four of them.

Pass a national carbon tax

Later in this congressional session, we're expecting a brutal fight over the Obama administration's plans to regulate greenhouse gas emissions from coal-fired power plants. But here's the thing: This fight could be easily avoided if Congress would simply pass a law to deal with these emissions, and thus preempt EPA's activity. A growing economists' consensus says the best way to do this is to put a tax on carbon, and then let the power of the market do its work.

By passing a carbon tax, we could not only avoid the fight over the regulations. We could actually generate new revenue that could be used for any number of beneficial purposes - including cutting every last American a monthly paycheck.

This, incidentally, would likely have a much more beneficial economic effect than Keystone XL would. For instance, one study commissioned by the Citizens Climate Lobby found that with a $10 per ton carbon tax (rising $10 per year), and with 100 percent of the revenue returned to Americans in the form of a dividend, the economy could gain as many as 2.8 million jobs over 20 years.

Exploit low gas prices

Nationally averaged gasoline prices are on a record plunge right now, having fallen for over 100 days straight and over $1 per gallon of regular gas. That means that people are paying shockingly less than they're used to for gas, which in turn creates a rare opening for raising the current 18-cent national gasoline tax - which has not been raised in two decades, but which is vital to restoring the ailing Highway Trust Fund.

In fairness, some have suggested that a better way to find funds to take care of our roads is a mileage-based highway user fee. But the same story goes: Driving has just gotten a lot cheaper, yet our highway infrastructure is in rough shape. So now's the moment for Congress to move to make driving a lot better in this country, and to set our infrastructure on a more financially sound footing.

Fix The Ethanol Mandate Mess

The so-called Renewable Fuel Standard, created by the 2005 Energy Policy Act and expanded in 2007, is a mess. The standard requires a fixed volume of ethanol and other renewable fuels to be blended into gasoline, starting with 9 billion gallons back in 2008, and increasing over time to 36 billion gallons by 2022.

But Congress passed these requirements without knowing how much overall fuel drivers would use in the future, or how economic conditions would develop. Thus, it has been hard to blend in the required amounts of ethanol and other renewable fuels in the fuel supply. Meanwhile, another thing holding everything up right now is the failure to create enough refueling stations to support flex-fuel vehicles that can run on E85 gasoline, which contains 85 percent ethanol.

Late last year, the EPA punted, rather than setting a required standard for how much renewable fuel energy companies would have to blend into their products in 2014. The agency now is more than a year behind in making rules under this mandate, and industry has announced plans to sue, objecting strongly to the regulatory uncertainty that this creates. But the problem is the standard itself: Congress should step in and fix the Renewable Fuel Standard, so that it achieves the original objectives - making our fuel supply more sustainable - without the current dysfunction.

Extend Renewable Tax Credit

Meanwhile, America's wind industry is also in a state of uncertainty - because late last year, Congress voted to extend a production tax credit that is vital to wind power, but only through the end of the year. And it only did so at the last minute, so that literally, wind power folks had only two weeks to take advantage before the tax credit was gone again. That's just a ridiculous way to treat a major sector of the energy industry. Congress should move to give the wind industry more stability and a stronger footing going forward, so that it, just like energy companies and the ethanol industry, can know what to expect.

So, in sum: Congress is going to hold a Keystone vote, and likely pass a bill that the president will veto - but there are many better things, on energy, that it might be doing.

Just saying.

Chris Mooney reports on science and the environment for the Washington Post.