Imagine a future of relentless storms and floods; islands and heavily inhabited coastal regions inundated by rising sea levels; fertile soils rendered barren by drought and the desert's advance; mass migrations of environmental refugees; and armed conflicts over water and other precious natural resources.
Then, think again--for one might just as easily conjure a more hopeful picture: of green technologies; livable cities; energy-efficient homes, transport and industry; and rising standards of living for all the world's people, not just a fortunate minority.
The choice between these competing visions is ours to make. Current trends may not be very encouraging, and certainly...