I was introduced to the concept of the metabolic rift in a public health class titled "Urban Space + Health," where we read a piece by Jason Moore titled "Environmental crises and the metabolic rift in world-historical perspective." Since then, Jason and I have used the concept to describe what motivates a lot of what we are trying to accomplish with our Longhaul project.
The metabolic rift is explicitly referring to ecological disruption as a result of capitalism, drawn from Karl Marx's theories on the relationship between humans and nature. In agricultural terms, it refers to soil degradation and the loss of soil fertility that has resulted from years of capitalist agricultural practices which take plant and animal products and resources from land (typically from "the country") without replacing it, instead exporting it to other land (typically "the city") for human consumption. The imbalance in the nutrient and ecological cycle caused by this rift is contributing to the crisis in sustainability we face today.
I think making the connection between tree, natural fuels, plant and animal resources being taken away from their sources to be used and never returned by the urbanizing, globalizing human population is not hard to do. We also think of the metabolic rift in terms of family and community: how our young and old are increasingly being taken care of by sourced-out entities, rather than by inter-generational extended families or community members. We also think about it when we collect organic matter from our neighbors and local businesses, turning their nutritious waste into locally-made compost that will feed the soil, rather than letting it end up in landfills.
So with our Longhaul project, which includes the ecologically sustainable farm, community connections, living closer to family, and in the coming years, a multi-generational educational space, we are attempting to heal the rift.