The chances that a bill limiting greenhouse gas emissions will pass the Senate this year are dwindling.

California Democrat Barbara Boxer, who chairs the Senate Environment and Public Works Committee, says the bill, which was supposed to be introduced when the Senate comes back from recess September 8, won’t be ready until later this month. (Boxer had earlier pushed the deadline back from August, according to the Wall Street Journal.)

That makes it less likely that the bill will pass the Senate before the United Nations climate-change meeting in Copenhagen in December. The House has already passed such a bill, which would have to be reconciled with the Senate version before climate-change legislation becomes law. Meanwhile, the Environmental Protection Agency is working on regulations for greenhouse gases that could go into effect if Congress fails to send a climate bill to President Obama.

It would be good for the United States to have climate-change legislation in place going into the Copenhagen meeting. If the United States is moving to limit its own emissions, other countries may be more willing to go along with a new international climate-change treaty. And there’s not much point in the United States curbing emissions if other countries, especially China and India, don’t.