At the end of March, representatives Henry Waxman and Ed Markey introduced an ambitious federal climate bill. This is the real deal — the legislative centerpiece of President Obama’s effort to combat global warming. Transportation contributes about a third of all greenhouse gas emissions in the U.S., so any climate bill will have to green the way we get around to be effective. On that score, however, the draft legislation has some glaring omissions.

It includes tougher national emissions standards for vehicles and incentives to develop plug-in hybrid infrastructure, but no funding for transit or more walkable development. There’s already a proposal circulating in Congress to link a cap-and-trade system with investment in transit and smart growth — the CLEAN TEA bill. Parts of CLEAN TEA have been incorporated into the Waxman/Markey bill, but not the core provision to dedicate 10 percent of the revenue from carbon auctions to green transportation projects.

That could change. Transportation for America is gathering signatures urging Congress to beef up the provisions for sustainable transportation in the climate bill. Adding the CLEAN TEA funding mechanism would translate to about $8 billion per year, based on the Obama administration’s projection for annual revenue from carbon auctions. Waxman’s committee will begin making changes to the bill on Monday, so now is time to sign on and speak up for stronger legislation.