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

CNN: Polluted rivers stain Portland's image

Nanotech also allows for "green manufacturing"--manufacturing processes that can take place at ordinary temperatures, reducing energy costs, while the use of non-toxic catalysts minimize pollution and bottom-up construction leaves no wasted material behind.

FORBES: Nanotech Vs. The Green Gang

In fact, according to the New York State Biodiversity Research Institute, that man-caused influence comes in fifth behind habitat degradation and loss, non-native invasive species, pollution, and overuse of resources.

FORBES: Got Problems? Blame Global Warming

Costs not captured include electrical grid upgrade, connectivity of renewables and buffering of their intermittency by rapid cycling of fossil fuel plants as presently practiced in this country, and non-carbon-tax externalities such as pollution and health care costs associated with energy sources, especially for coal.

FORBES: The Naked Cost of Energy -- Stripping Away Financing and Subsidies

Across the country, special fares were on offer in operation on public transport, exhibitions will show the effect of pollution on people and buildings, and new non-polluting types of transport will be on display.

BBC: News | Europe | Off the roads

The conservation group says the problem is responsible for pollution, shrinkage of coastal wetlands and the tapping of non-renewable groundwater in some regions.

BBC: NEWS | Science/Nature | Tourism damaging Med's wetlands

This does not surprise environmentalists, who have long argued that any policy of pollution-reduction that does not include a threat of punishment for non-compliance is useless.

ECONOMIST: The Lone Smog State