Earth, air and water are far cleaner as a result, even if still far from pristine.

And of course, ethanol burns far cleaner that fossil fuels.

No, her technique is far cleaner and more polished than mine could ever hope to become.

America's air and water are far cleaner than they were two decades ago.

Not much, because the manufacturers can make cars far cleaner without resorting to major new components.

Diesel engine exhaust has become far cleaner since 2000.

By the first decade of the 21st century, Pittsburgh's rivers were far cleaner than they had been 100 or 50 years earlier.

On planes, at least, the air is far cleaner than it used to be.

Gasoline mowers made after 2000 run far cleaner than older models.

The fuel will be far cleaner, but no more expensive, than what is now available at filling stations.