After the latest presidential debate, yet another ad from oil company Chevron appeared on ABC. At the same time the network refused to run an ad that blames large advertising campaigns by Big Oil and coal as a reason for the gridlock on clean energy in Washington.

The ad titled “Repower America” was produced by Al Gore’s nonprofit organization We Can Solve It. Here’s the script of the ad:

The solution to our climate crisis seems simple.

Repower America with wind and solar.

End our dependence on foreign oil. A stronger economy.

So why are we still stuck with dirty and expensive energy?

Because big oil spends hundreds of millions of dollars to block clean energy.

Lobbyists, ads, even scandals.

All to increase their profits, while America suffers.

Breaking big oil’s lock on our government …

Now that’s change.

We’re the American people and we approve this message.

The We Campaign CEO Cathy Zoi is asking people who agree with the ad’s message to send a letter to the Disney-owned network encouraging the paid airing of the ad Friday evening during “20/20.”

A conservative free market Web site Business Media Institute defended ABC by saying that the network is planning a special feature on the dangers of global warming in 2009 (and therefore no friend of Big Oil). The site does note, however, that in its study of the TV networks’ openness to global warming skeptics, ABC was rated “the best”:

• Disagreement Squashed: Global warming proponents overwhelmingly outnumbered those with dissenting opinions. On average for every skeptic there were nearly 13 proponents featured. ABC did a slightly better job with a 7-to-1 ratio, while CBS’s ratio was abysmal at nearly 38-to-1.

ABC has yet to offer an explanation for its refusal.

(Todd Spencer contributed to this report.)