The Carbon Calculator from Carbon Footprint Ltd is a breath of fresh air for carbon and sustainability! They are ISO14001 certified and offer services to individuals and businesses of all sizes to help take your sustainability to the next level.
You can also check out:
The Greenhouse Gas Protocol: Standards and guidance regarding corporate greenhouse gas accounting and reporting. Offers business-oriented tools for calculating carbon inventories, such as emissions from employee commuting or from working with various materials such as metals or lime.
Climate Change Hamilton 