The EPA has denied California the right to enact its own greenhouse gas emissions regulations for automobiles. EPA administrator Stephen L. Johnson said: "The Bush administration is moving forward with a clear national solution -- not a confusing patchwork of state rules -- to reduce America's climate footprint from vehicles." But calling it a "patchwork" is misleading since at present, there are only two options for other states when it comes to greenhouse gas emissions standards: stick with the EPA's or copy California's.

Yesterday, the European Union came out with its final proposals for cleaning up the continent's cars. This from The Economist:

At present Europe’s cars emit an average of about 160 grams of CO2 per kilometre (g/km). There has been some reduction since carmakers were last threatened with legislation a decade ago, but progress has been painfully slow—about 1.5% a year rather than the 3% needed to meet the voluntary target of 140g/km by 2008 that the industry agreed to a few years ago. The commission is therefore insisting that by 2012, the fleet-average emissions from new cars sold in the EU must not exceed 130g/km, with another 10g/km reduction coming from other sources, such as low rolling-resistance tyres, more efficient air-conditioning and greater use of biofuels.

Mercedes-Benz and BMW aren't taking the news very well.

The Guardian (London) has a piece on ethical living in which the paper exposes carbon myths. For example:

Myth 4 Hybrid cars are the way forward

There is nothing wrong with hybrid petrol/electric cars. But they are an extraordinarily expensive way of avoiding emissions. The Toyota Prius may be lovely, but its emissions are no better than the latest generation of small diesels, which cost little more than half the price. Buy a small car instead and spend the savings on insulating your walls. It will have far more effect. Worried about the effect on your status of driving a small car? Buy an electric vehicle and people will simply think of you as eccentric.

Also from The Guardian and related to air quality is news that cannabis smokers are exposed to more toxic chemicals in each puff than cigarette smokers. If you're wondering who partook in testing the weed, the answer is no one. Scientists set up machines to"smoke" the plants and collect the fumes.

In tests, directly inhaled cannabis smoke contained 20 times more ammonia than cigarette smoke, five times more hydrogen cyanide and five times the concentration of nitrogen oxides, which affect circulation and the immune system.

And in San Francisco, Mayor Gavin Newsom is trying to make the Bay Area a more livable place. He's not cleaning up the air -- rather, he's proposed charging big stores a fee when they sell sugar-sweet soda.