This article comes from the December 2012 issue of GSA Today, the Geological Society of America's monthly journal.
Citation: Hooke, R.L., Martin-Duque, J.F., and Pedraza, J., 2012, Land transformation by humans: A review: GSA Today, v. 22, no. 12, p. 4-10
This is the html link to the article: http://www.geosociety.org/gsatoday/archive/22/12/article/i1052-5173-22-12-4.htm
Synopsis: This is a somewhat odd first choice for my blogging efforts, because it does not address climate change at all, but rather land-use change. However, it's not that odd when you consider the role that changing land-use has on the climate system (e.g. cutting/burning of rain forests takes carbon stored in biota and transfers it to the atmosphere). Perhaps more importantly, the direct impacts of current [unsustainable] land use practices put pressure on us as a species to maintain the necessities of life (high agricultural production rates, access to clean water resources, etc.). With added pressure from rapidly changing climate, our ability to support ourselves (in the biological sense) becomes even less certain. Anyway, this paper draws heavily from previous more quantitative research, and its results depend in some ways on how the authors define terms and what assumptions they make. Importantly, they make conservative estimates and despite this conservatism, determine that "~70 Mkm^2, or >50% of Earth’s ice-free land area, has been directly modified by human action involving moving earth or changing sediment fluxes. Many of these activities have indirect consequences well beyond the area directly affected." Implicit in this statement is that much of this modification by human action has negatively affected the land. That aside, the authors look at the rates at which we modify land and determine that, given our current population and land-use patterns, we are almost certainly operating beyond our biological carrying capacity. If we are not currently in overshoot, then the current rate of population growth will certainly bring us to that point within the next century or two. Like any other species, we will adapt to this condition of overshoot by first experiencing a decline in the standard of living, and then, secondly, by reducing the population (read: more people die of starvation and disease and less children are born).
