Geoscience Reference
In-Depth Information
Yes, the impacts are highly dependent on local climatic conditions as well
as soils, management practices, and market availability. Yes, some regions
will experience warmer and drier conditions. So some regions will un-
doubtedly be severely affected, particularly if adaptation is limited.
But adaptive forces are also very powerful. Farm technologies have
evolved greatly in most regions. Over the last century, the prices of farm
products have been declining, and the share of most economies devoted
to farming has been shrinking. The output of farms is increasingly sold
in global markets, so the impact of localized climate change on con-
sumption will be buffered by market forces and adaptation. Moreover,
people can and do move away from regions that experience severe shocks
to local industries, particularly over the longer run. Most important,
societies have many adaptations they can make in the face of changing
conditions.
However, while studies suggest that impacts on farming will be
small for the next half century or so, we must also put in the balance
concerns about the longer run. The odds in the Climate Casino become
increasingly unfavorable with more extensive climate change, particu-
larly when the global temperature increase exceeds 3°C. In the long run,
with unchecked accumulations of CO
2
and the accompanying changes,
the projections become much more uncertain and the risks rise of tip-
ping points such as changes in monsoonal patterns or major changes in
ocean currents.
What is the summary judgment here? The best evidence is that the
economic impact of climate change on overall economic welfare through
agriculture is likely to be small over the next few decades. The impact
will be declining as countries develop and move their labor force out of
the farm sector. Over the longer run, the outlook is cloudier, especially
if climate change is unchecked. If global temperatures rise sharply,
changes in precipitation patterns and abrupt changes are more likely to
cause substantial impacts on food production.
