The Green movement encompasses the Green parties and the larger ecology movement, peace movement, conservation movement, environmental movement and general trend towards environmentalism of which they are a part - the most extreme members of which are sometimes called Gaians or terrists. A more mainstream term for a member of all of these movements is political ecologist, which is used especially in Europe and academic circles.
Not all political ecologists or "Greens" are necessarily active in parties or Green politics. Many Greens disdain electoral politics as a matter of conscience, refusing to participate in violent processes of defining and enforcing laws. These often make reference to the nonviolence ideals of Mohandas Gandhi, although in historical fact Gandhi was actively involved in party politics his whole life.
Greens also often support traditional "left" socialist or "right" capitalist parties as part of a Red-Green Alliance or Blue-Green Alliance or to achieve some tactical purpose. For example, in the 2000 US election some Movement Greens started "Greens for Gore" to support then-US Vice President Al Gore of the United States Democratic Party against US Green Ralph Nader, who threatened to "split the vote" and elect opponent George W. Bush, whose views Greens saw as incompatible with environmentalism.
A range of views from Natural Capitalism to those of the Gaians span the left-right spectrum - which many Greens claim does not apply to them or their long-term "seven generation" perspective. Critics claim that Greens who do not commit to Green parties are pursuing short-term goals. Others claim that those who do are simple opportunists avoiding the necessity of aligning themselves with a specific interest group of voters, and pursing single-issue politics. As with everything in politics, any decision is wrong, but not making a decision is also wrong.
There is no single test or metric to determine who is or is not a member of the Green movement, but most Greens would agree that the Four Pillars originally defined by European Green Parties form the basis of unity on which Greens base their ecological consensus process, and which have been adopted elsewhere especially in the peace movement.
Some think that Green movement ideals converge to a degree with religious thought, e.g. Buddhism, some strains of Catholicism including Thomas Berry's views, and modern Islamic philosophy of al-Faruqi and Nasr. Reconciling these with the Green ideal of feminism is a problem, but there is much similarity, e.g. between Islamic economics and Green economics. These movements all agree that ethics must subordinate the scientific method where the latter is likely to lead to dangerous changes, i.e. the Precautionary Principle applies even to the most basic research.
See also: Greenpeace