Here are some examples of many other energy saving / environmental projects - each of which is a business opportunity, as well as an opportunity to help the environment.

Expect 5% of all expenditure on reducing carbon use to be spent on advisors, technical consultants, energy auditors, regulatory compliance and related services.   That’s a potential market of £20bn a year globally - 3% of total annual spending of up to $2 trillion.

Keynote speaker on logistics and supply chains.

Aviation produces up to 5% of national carbon emissions in countries like the UK, growing every year  - 2% globally.  However, because of the relative impact of vapour trails, cirrhus cloud formation and other factors, it is likely that this 2% represents 3.5% - 5% of the total human impact of global warming. 

Many aircraft flying today were made over 25 years ago and waste fuel. Simple steps can be taken to improve fuel efficiency in older planes – by as much as 7%.

Future of Aviation post written in 2009 - very accurate.