Paul Raskin et al., Great Transition: The Promise and Lure of the Times Ahead (Boston: Stockholm Environment Institute, 2003)
A short but deeply thought through assessment of the possible future scenarios facing humanity.

Al Gore, The Future: Six Drivers of Global Change (New York: Random House, 2013).
A thorough and discerning evaluation of the major drivers for change in our global society, and their implications for the future.

Joseph A. Tainter, The Collapse of Complex Societies (Cambridge: Cambridge University Press, 1988).
A scholarly analysis of societal collapse that has deservedly framed much serious discussion on the topic since its publication.

Jorgen Randers, 2052: A Global Forecast for the Next Forty Years (White River Junction, VT: Chelsea Green, 2012).
A thoughtful projection into the future by one of the original team members of Limits to Growth.

Thomas Berry, The Great Work: Our Way Into the Future (New York: Three Rivers Press, 1999).
A penetrating and visionary account of the enormity of the challenge and opportunity facing humanity in the future.