But today's problem of non-point source pollution is more difficult to control.

CNN: Polluted rivers stain Portland's image

Others point to pollution from old coal mines.

NPR: Cause Of Off-Color, Fetid Water Eludes Pa. Town

To be sure, the exodus of expatriates fleeing pollution hasn't reached the point where it is threatening the operations of global companies.

WSJ: Why Leave Job in Beijing? To Breathe

The point is not that there should be no pollution at all.

ECONOMIST: Taxes for a cleaner planet

Whether electric cars help solve the problems of pollution or global warming is a moot point.

ECONOMIST: How green and safe are they?

And sceptics point to a plant in Kirklees that exceeded its pollution limits after a boiler accident evidence that incinerators are not as safe as their manufacturers claim.

ECONOMIST: Tough landfill targets prompt a return to flaming rubbish

At some point people will take notice of the massive amounts of pollution and waste that is created from these sports leagues and demand that something is done, but why not do it because it is the right thing to do socially as well as economically?

FORBES: Earth Day Guest Post: Five Ways Pro Sports Can Get Greener