Americans may find out soon whether liberals in Congress are serious about global warming. Insight may be provided through a report concerning ethanol and pollution. Specifically, there is a question over whether the EPA will rely on science - or will be influenced by politics.

Two years ago the Environmental Protection Agency was instructed to propose pollution standards for ethanol. In other words, the EPA was told to determine what, if any, risk is posed by emissions from burning ethanol in internal combustion engines.

It might seem that such a study would have been undertaken before the government threw its support behind vastly increased production and use of ethanol. But ethanol is quite a political fad, in many respects an irrationally popular alternative to petroleum-based fuels.

Some members of Congress already have attempted to frontload the EPA's study. According to The Associated Press, Congress, in ordering the EPA study, "also told the agency to show that ethanol would produce less pollution linked to global warming that would gasoline."

You read correctly: Some lawmakers don't care about the science. The politics of farm state support and claiming that they are supporting a viable alternative to imported oil is more important to them.

But some environmentalists say that a comprehensive study of ethanol will show that increased use of it does contribute to global warming. Whether the EPA study reaches that conclusion depends on the agency's methodology, say the environmentalists.

Beyond any doubt, the EPA will be under enormous political pressure from both sides of the argument. That makes it absolutely essential that Americans review the report objectively and comprehensively - to determine whether it is science or politics.