Environmental community building
This article describes on how to build an environmental community.
How to become environmental 
See Juridical national measures on climate change for instructions on becoming environmental. Also see Juridical_national_measures_on_transport,_politics_and_education for extra suggestions.
Types of communities 
On land 
Communities may be made out of towns in the developed world and in the developing world.
In the developed world, intentional/new-age communities found at the wikipedia may be used; see List of intentional communities and New Age communities. See also the appropriate technology-wikipedia article.
In the developing world, indiginous communities (eg those depicted in the BBC's Tribe-series; see http://www.bbc.co.uk/tribe/ ) are probably the best to target since many of them are already suffering from climate change. More info may be obtained from organisations mentioned at this BBC-website (eg Survival International, ...) aswell as Cultural Survival, ... A list of ethnic communities may also be found at this Wikipedia-article. Also, religious centra that have a intrest in ecology (eg Association of Buddhists for the Environment, ...) may join in, a list of notable centra is available at The Alliance of Religion and Conservation. Appropriate technology organisations (eg Practical Action, ...) may be used to reduce the price of the equipment needed for microgeneration, ... Examples on how the the technology may be created DIY can be seen on programs such as Planet Mechanics Also, abandoned cities may be used to create the communities, see Cheap acquiring of towns and large buildings
On sea 
A special community may also be build at sea; see Cheap_acquiring_of_ship#Community-creation
Gathering extra workforce 
In order to be able to construct more buildings, or enlarge the ecological projects (eg tree plantations, ...), extra workforce may be obtained from homeless and/or poor people. Also, people that leave in unhuman conditions or those that live in conflict zones (eg Somalia, parts of Kenia, slum villages in India as Dharavi, slums in Rio de Janeiro, Palestine, DR Congo, Central African Republic, ...) may be transported to the project sites. This can be done trough low-cost, bulk transportation (eg industrial vessels) within a larger project, condoned/sponsored by humanitarian organisations as UN Habitat. This operation would have benefits to the project (lower cost) and allow the volunteers of escaping their desperate situation and build up a humanworthy life.
Communities may help out each other trough money lending and sharing. See this page