23
are rising and will continue to rise at a rapid pace. Although climate models often
do not agree on precipitation changes, there is considerable agreement on the trends
in some locations. Moreover, precipitation is becoming more extreme in many
places, often resulting in too much rain, too little rain, or rain that falls at the wrong
time. A location might experience more overall rain during the growing season, but
if it falls intensively in the beginning or middle of the season, the end of the season
might be too dry, especially as hotter temperatures dry out soils. A single location
might experience increased flooding during the middle of the rainy season and
increased aridity later. This situation creates a need for crop varieties that can withstand waterlogging, help prevent erosion from heavy rains, and reach maturity during a shorter growing season.
Recent studies show that the types of management practices beneficial for adaptation and increased productivity are highly varied (Challinor et al. 2014; Lamanna
et al. 2016). For instance, a recent review and meta-analysis of field studies in
Uganda and Tanzania found more than 20 practices in each country that could
improve adaptation and productivity, each with varying effectiveness depending on
the farming system and site in question. The use of fertilizers (both organic and
inorganic) and water saving techniques generally have the largest positive effects on
crop productivity (Lamanna et al. 2015). Similar findings have been reported elsewhere in Africa (Rosenstock et al. this volume).
Improving the available crop varieties is a key mid-term strategy to increase
productivity, improve production stability and adapt to projected climate changes.
For example, although climate change will hurt bean production across Africa
(Rippke et al. 2016; Ramirez-Villegas and Thornton 2015), heat-tolerant bean varieties could greatly reduce the impact (CIAT 2015). Current work on inter-specific
crosses between common and tepary bean show promise for creating breeding lines
that maintain yield under heat stress (CIAT 2015). Similarly, drought-tolerant varieties of maize could be an option for adaptation to reduced or inconsistent rainfall
(Cairns et al. 2013; Rippke et al. 2016).
In the long-term, planned transformations will be required for some areas.
Rippke et al. (2016) report that some 3–5% of the arable land of sub-Saharan Africa
may require a transformation out of crop-based systems to either livestock-based
systems or to an entirely new land use.
2.4.2 Collecting and Using Climate Data
Historical data and climate projections clearly establish the need to act quickly to
help African farmers adapt to a changing climate. Too often, however, CSA interventions are being promoted without a proper understanding of the climate risks for
the specific areas involved. In some cases, reliable information on tightly focused
geographical areas simply has not been collected. And even when good information
is available from climate models and impact studies, often this information is not
2 Future Climate Projections in Africa: Where Are We Headed?
are rising and will continue to rise at a rapid pace. Although climate models often
do not agree on precipitation changes, there is considerable agreement on the trends
in some locations. Moreover, precipitation is becoming more extreme in many
places, often resulting in too much rain, too little rain, or rain that falls at the wrong
time. A location might experience more overall rain during the growing season, but
if it falls intensively in the beginning or middle of the season, the end of the season
might be too dry, especially as hotter temperatures dry out soils. A single location
might experience increased flooding during the middle of the rainy season and
increased aridity later. This situation creates a need for crop varieties that can withstand waterlogging, help prevent erosion from heavy rains, and reach maturity during a shorter growing season.
Recent studies show that the types of management practices beneficial for adaptation and increased productivity are highly varied (Challinor et al. 2014; Lamanna
et al. 2016). For instance, a recent review and meta-analysis of field studies in
Uganda and Tanzania found more than 20 practices in each country that could
improve adaptation and productivity, each with varying effectiveness depending on
the farming system and site in question. The use of fertilizers (both organic and
inorganic) and water saving techniques generally have the largest positive effects on
crop productivity (Lamanna et al. 2015). Similar findings have been reported elsewhere in Africa (Rosenstock et al. this volume).
Improving the available crop varieties is a key mid-term strategy to increase
productivity, improve production stability and adapt to projected climate changes.
For example, although climate change will hurt bean production across Africa
(Rippke et al. 2016; Ramirez-Villegas and Thornton 2015), heat-tolerant bean varieties could greatly reduce the impact (CIAT 2015). Current work on inter-specific
crosses between common and tepary bean show promise for creating breeding lines
that maintain yield under heat stress (CIAT 2015). Similarly, drought-tolerant varieties of maize could be an option for adaptation to reduced or inconsistent rainfall
(Cairns et al. 2013; Rippke et al. 2016).
In the long-term, planned transformations will be required for some areas.
Rippke et al. (2016) report that some 3–5% of the arable land of sub-Saharan Africa
may require a transformation out of crop-based systems to either livestock-based
systems or to an entirely new land use.
2.4.2 Collecting and Using Climate Data
Historical data and climate projections clearly establish the need to act quickly to
help African farmers adapt to a changing climate. Too often, however, CSA interventions are being promoted without a proper understanding of the climate risks for
the specific areas involved. In some cases, reliable information on tightly focused
geographical areas simply has not been collected. And even when good information
is available from climate models and impact studies, often this information is not
2 Future Climate Projections in Africa: Where Are We Headed?