Humans have become a major geological force with the power to commit future millennia to practically irreversible changes in global conditions. This is what Bill McKibben refers to as "The End of Nature." As an example of the impact life has on global climate, the imminent global warming caused by humans does not stand out as unique or even unusually impressive. When oxygen-generating photosynthetic algae evolved between one and two-and-one-half billion years ago, they changed the composition of one-fifth of the atmosphere, poisoned much of the previous ecosystem, and more or less terminated the dominant role of methane as a greenhouse gas (oxygenation also, to be fair, set the stage for evolution of multi-celled organisms-the animals and plants we know and love). And when plants colonized land half a billion years ago, they vastly increased the rate at which atmospheric carbon dioxide is converted to limestone in the soil, leading to severe global cooling. One hardly wants to contemplate the kind of environmental impact statement that would have to be filed for either of these innovations. What makes global warming unique in the four billion year history of the planet is that the causative agents-humans-are sentient. We can foresee the consequences of our actions, albeit imperfectly, and we have the power, if not necessarily the will, to change our behavior so as to effectuate a different future. The conjuncture of foresight and unprecedented willful power over the global future thrusts the matter onto the stage where notions of responsibility, culpability, and ethics come into play. The philosopher Hans Jonas finds in this "imperative of responsibility" a need for a fundamentally new formulation of ethics-one that takes greater cognizance of future generations and of the biosphere at large. It is against this backdrop that the foundation of international institutions capable of dealing with the catastrophe of global warming must be seen.
Pierrehumbert, R. T.
"Climate Change: A Catastrophe in Slow Motion,"
Chicago Journal of International Law:
2, Article 6.
Available at: http://chicagounbound.uchicago.edu/cjil/vol6/iss2/6