Climate Change and Agriculture - The Oxford Topic of Food, Politics, and Society - page 453

change. That is one possible scenario. However, in less apocalyptic scenarios, climate
effects grow much more linearly and with increasing obviousness, as better data on
temperature shifts and the frequency of extreme weather shocks become available. The
cumulative impacts of climate change could occur in gradual proportionality, meet up
against unexpected, irreversible thresholds, scale up geometrically, or follow even more
chaotic patterns (Brown 2009; Pinstrup-Andersen and Watson 2011).
The larger and more dramatic we expect climate change to be, the more important it
will be to invest in improving agricultural productivity and reducing poverty. Consider
the food price spikes in 2006-2008. Did changes in weather, soil, and air lead directly
to the sudden increase in food price volatility starting in 2006, spiking as the climate
and planet passed a critical threshold? Or did its effects come much more indirectly, as
anticipations of climate change encouraged legislatures to mandate the pursuit of biofu-
els, just as speculators and investors alike turned their attention to food crops at a time
of low stocks? In some ways, it is very difficult to separate these intertwined stories, yet
they have profoundly different implications for the kind of policy that should be pur-
sued going forward. If the former is more accurate, then these biofuel policies may be
an essential ingredient in mitigating global warming; if the latter, the policies should
be abandoned before greater harm is done (see Pimentel and Burgess, this volume). In
either case, investments in long-term agricultural productivity would ameliorate local
price fluctuations, and reductions in poverty would enable more people to cope with
(direct and indirect) climate shocks.
The uncertainties surrounding how much climate will change and what its effects
will be have led to many varying estimates of what to expect from climate change in
the twenty-first century, ranging from doomsday scenarios to the relatively benign.
Schwartz and Randall (2003) predict climate change will lead to nuclear war and Roberts
(2008) foresees “The End of Food” with climate change playing a participatory role.
Ereaut and Segnit (2006) show that alarmism is the most frequent rhetorical device used
to discuss climate change. More measured reports that predict severe climate-induced
outcomes include Willenbockel's (2012) estimations of extreme weather events leading
to a doubling and trebling of food prices from their 2006-2008 food crisis levels and
World Bank (2012) that warns that even moderate warming could lead to irreparable
harm, mass exodus, further deforestation, and famine. The prominent Stern Report2
(Stern 2007) estimated that it would cost roughly 1 percent of global production to make
the investments necessary to avoid significant damage.
One thing each of those studies shares is a deliberate selection of unlikely negative
outcomes. IPCC (2007 and 2012) has, in part, justified this by highlighting that past esti-
mates of how much some variables would change (e.g., arctic temperatures) have con-
sistently underestimated reality by significant margins. There is evidence, however, that
newer models designed to address this are instead becoming more precise and less accu-
rate in measuring global mean temperatures and the frequency of extreme temperatures
(Swanson 2013).
Studies that examine the full range of possible climate outcomes tend to support the
notion that negative outcomes for sub-Saharan African agricultural productivity before