The EU is pushing ahead with plans to bring airlines into the carbon emissions trading scheme, according to Fiona Harvey in the Financial Times (2006-08-01):
The European Commission will decide this autumn how soon aviation can reasonably be brought within the scheme. The first phase of the scheme ends next year, and the second will run [...]

From Sharlene Goff, in the Financial Times (2006-07-29):
There are a number of routes for private investors to gain access to the carbon trading market. …

You can get direct exposure to carbon reduction projects by going through a broker, such as Evolution Markets or TFS. These companies have links to energy project developers and can seek [...]

The UK and the US state of California have signed an agreement to work together to reduce greenhouse gas emissions, and to promote low-carbon technologies. See the BBC report. California, under Governor Arnold Schwarzenegger, has been well ahead of the Bush Administration in action on climate change, despite Arnie also being a Republican.
UPDATE (by Jez): [...]