Since the Intergovernmental Panel on Climate Change (IPCC) was
formed in 1988, it has engaged a substantial proportion of those
individuals with relevant scientific expertise in the process of
forming reasonable judgments about the effects of aggregate human
activity on the composition of the earth's atmosphere and about the
resulting implications for global climate. It is now widely agreed that
in concert with other so-called "greenhouse gases," carbon dioxide
(CO2) released from the burning of fossil fuels for energy is causing
the earth's climate to change. Over the last century, the concentration
of CO2 in the atmosphere increased from about 300 to 375 parts per
million by volume (ppmv), and global average surface temperature
increased by 0.4 to 0.8 oC. In the absence of policies designed to
substantially reduce global emissions, scenarios developed by the IPCC
indicate that CO2 concentrations will reach 550 to 1000 ppmv in 2100
and that global average surface temperature will increase by an
additional 1.5 to 6 oC (IPCC 2001a).
consequences of such a temperature increase and associated changes in
precipitation patterns and other climate variables are a matter of
greater uncertainty and disagreement. At the lower end of the range, it
is possible that nothing of global consequence will occur, and that the
regional and more localized effects will be moderate enough to be
handled by natural adaptation. It also conceivable"particularly at the
high end of the temperature range"that abrupt, nonlinear and
fundamental changes could be triggered, such as a sudden change in
large-scale ocean currents, with truly massive and potentially
catastrophic consequences for human societies. The IPCC has identified
the possibility of extreme danger, but has been and will remain unable
to reach consensus on its exact character, magnitude, probability and
That situation presents an extraordinary
problem of risk management. It is feasible in principle but
monumentally demanding to limit the atmospheric concentration of
greenhouse gases resulting from aggregate human activity. Moreover, the
will and capacity to do so would have to be generated in advance of
scientific consensus about the danger to be avoided. If business
continues as usual, however, any scientific consensus that might form
about catastrophic climate change is likely to emerge only after it is
too late to take action to avoid it.
Any effort to reduce emissions which restrains global economic output threatens the developing world with prolonged stagnation and hopelessness, setting the stage for increased civil conflict and international violence. Although the relevant relationships are not yet understood in detail, it is widely suspected that violence is generated by the sustained denial of economic opportunity. Thus, security in the globalized world economy ultimately depends on a more equitable pattern of economic development than has yet been achieved.
Steve Fetter is dean of the School of Public Policy at the University of Maryland.
Tim Gulden is a Research Fellow at the Center for International and Security Studies at Maryland.