I will first examine four different proposals about sustainability. Each has its own account of what features of the environment are worth saving or are necessary to save—whether human or nonhuman. Consequently, each has a different account of what is harmfully unsustainable. And then each also has a correspondingly different account of sustainability, of how we humans must modify our actions in order save valuable or necessary features of the environment.
The four accounts are:
Mark Lynas’(2011) technophile goal of raising the entire population of earth to first-world levels.
E. O. Wilson’s (2002) vision of cooperation between environmentalists and corporations.
Lester Brown’s Plan B 4.0 (2009), a detailed plan for attaining sustainability.
Dave Foreman’s (1991, 2011) agenda for protecting the earth.