Results for income changes among urban households are
mixed. The negative effect for upper-income urban households can be explained by the reduced return on skilled labor
and capital, whereas for lower-income urban household, the
higher return on low-skilled labor slightly improves their
overall income levels. Nevertheless, rural households benefit
more than the urban household across comparable income
levels.
POLICY IMPLICATIONS
Crop Modeling Analyses of Direct Climate Impacts
The direct impact of climate change on irrigated crops is less
than the impact on rainfed crops, at least in regard to the
two irrigated crops examined for this study. Climate change
is projected to have large, negative impacts on maize, and
the impacts are fairly uniform across the country—with the
exception of Visayas, where the impact is slightly more negative. Careful analysis of monthly rainfall and temperature
patterns with and without climate change indicates that
these results are consistent with documented yield impacts
of higher temperatures on maize. Because maize is such an
important crop in the Philippines, results suggest that careful
consideration should be given to adaptation strategies targeting maize, in particular. Furthermore, because yield
losses are reasonably high for both rainfed rice and rainfed
sugarcane in Luzon, and all major crops are projected to be
affected, adaptation strategies in that region will require
particular attention. This also limits the strategies for maize
adaptation in Luzon because one of them, relevant in the
rest of the country, is to cultivate alternative crops, such as
rice or sugarcane.
There are still possibilities for adaptation, however. Investment in agricultural research could result in heat-tolerant varieties of maize, rice, and sugarcane. The Rosegrant et al.
(2014) study suggested that heat-tolerant varieties would
only provide modest benefits, but that study used the AR4
climate models, and so perhaps did not project the same
kind of losses resulting from this more recent analysis with
the newer AR5 models. One possible alternative to heat-tolerant varieties that would nonetheless help with losses due
to hotter temperatures would be the development of
shorter-duration varieties that would allow farmers to plant
in cooler months, and yet not miss out on months with suffi
10
cient rainfall for a good yield. Rosegrant et al. (2014) showed
that no-till cultivation of maize could lead to much higher
yields, as could improved pest protection, and—best of all—
SUMMARY | APRIL 2010
integrated soil fertility management.
For farmers who currently under-utilize fertilizer, increased
use could be an effective means of adapting to climate
change. This would especially be the case in the presence of
rising food prices, which could in fact rise faster than fertilizer prices. Of course this does not necessarily mean the use
of chemical fertilizers. Better use of manure or nitrogen-fixing plants—either as cover crops, through inter-cropping, or
in rotation—might be an effective solution.
In irrigated areas, slightly shifting the growing season for
rainfed crops to avoid the hottest months is a potential
strategy, as is supplementing rainfed crops with irrigation
while still using irrigation for the off-season crops. Such a
strategy will often require careful consideration of the impact on both crops. The use of shorter-duration varieties for
both crops may also be of great benefit in enhancing the
success of this adaptation strategy. In areas that do not currently have irrigation but have that potential, investment in
irrigation may be highly beneficial in overcoming the limitations of rainfed agriculture, under which some farmers may
otherwise be forced to plant in the hottest (albeit wettest)
months. Finally, Rosegrant et al. (2014) noted reasonably
large potential improvements in irrigated rice productivity
from the implementation of precision agriculture.
Policy Insights from the Phil-DCGE Model
In a simulation experiment, the Phil-DCGE model was used
to evaluate a couple of policies that would potentially assist
the Philippines in adapting to climate change. These results
are presented in more detail in Project Policy Note 1, but are
worth reiterating here. The first was to evaluate the results
of investment in agricultural research for the purpose of increasing rice productivity and close the yield gap by about 30
percent. The second experiment was to explore a policy of
reduced trade barriers on agriculture and food commodities
to minimize the increasing domestic commodity price in the
event of climate change.