Theory of change
A theory of change is “a strategic process by which we identify a winning approach to achieving positive change, as well as the specific steps and tactics that are needed to achieve that change." -Ella Baker School of Organizing 
The classic components of a theory of change are the headings “IF, THEN and BECAUSE”
IF - If we bring people together around us, through a series of diverse campaigns that address the injustices of our current system, whether social, racial, colonial, environmental or all of these,
THEN - We will build a base of climate justice activists in city X that will be diverse and powerful enough to challenge those who currently hold power (in society or at the local, provincial or National level)
BECAUSE - We will have brought climate justice to life as a movement and the people negatively affected by our system are many, while the people in power are few.
Note that in the example above, as in many general theories of change, goals, planning, and results do not have to be specific. However, there emerges at least a minimal sense of direction, namely "we need to grow and diversify our base of support to get there".
Starting from a common theory of change, the group can then define areas of intervention supporting the general approach. Ideally, each focus area should be assigned to a person or group responsible for leading a discussion of the focus area's campaign strategy to define concrete plans, goals and milestones.
Although we present a rather vague process, with many details to complete, the truth is that groups find many different ways to come together and align on a vision. A great example of how one group has gone about this is presented in the following Climate Justice Toronto's restructuring process. 
If you have any suggested revisions or additional resources to share related to the above content, please email them to email@example.com.