Climate change impacts on crop yields and adaptive measures for agricultural sector in the lowlands of Lesotho
(2010) In Lunds universitets Naturgeografiska institution - SeminarieuppsatserDept of Physical Geography and Ecosystem Science
- Abstract
- Summary: Climate change has emerged as the most outstanding of the environmental challenges and there
is a necessity to evaluate its impacts on the vulnerable development sectors such as agriculture.
In this study, spatially adjusted general circulation models and crop models were used to
simulate climate change scenarios and the associated cereal crops yields for the western lowlands
of Lesotho for the year 2030-2050 and 2080-2100. Focus was placed on three main cereal crops
namely sorghum, wheat and maize. The models predicted an increase in monthly mean
temperature and a decline in monthly rainfall for the area. With these variations on temperature
and rainfall, the study indicated that the yield per hector for the three cereals... (More) - Summary: Climate change has emerged as the most outstanding of the environmental challenges and there
is a necessity to evaluate its impacts on the vulnerable development sectors such as agriculture.
In this study, spatially adjusted general circulation models and crop models were used to
simulate climate change scenarios and the associated cereal crops yields for the western lowlands
of Lesotho for the year 2030-2050 and 2080-2100. Focus was placed on three main cereal crops
namely sorghum, wheat and maize. The models predicted an increase in monthly mean
temperature and a decline in monthly rainfall for the area. With these variations on temperature
and rainfall, the study indicated that the yield per hector for the three cereals would decline
considerably. These findings suggest that Lesotho should initiate adaptive measures, such as
switching to drought resistant crops, in order to offset the negative impacts of climate change on
crop yields. The government is advised to organise small farming groups into larger farming
communities and to strife for efficient irrigation. Research geared towards the development of
technologies that may equip farmers to adapt to climate change effects is recommended for the
country. (Less) - Abstract
- Climate change has emerged as the most prominent of the global environment issues and there is
a need to evaluate its impact on the agriculture. General Circulation Models (GCMs) which are
considered as the most advance tools for estimating future climate change scenarios operate on
coarse resolutions. It is for this reason the climate change model MAGICC coupled to SCENGEN
developed by the IPCC was used for climate change simulations, since it has an advantage of
having spatially adjusted GCMs. This study was conducted in Lowlands of Lesotho, which is
situated in the western part of Lesotho.
In order to estimate the level of climate change impact on the three main cereal crops in terms of
cropped area and production (sorghum,... (More) - Climate change has emerged as the most prominent of the global environment issues and there is
a need to evaluate its impact on the agriculture. General Circulation Models (GCMs) which are
considered as the most advance tools for estimating future climate change scenarios operate on
coarse resolutions. It is for this reason the climate change model MAGICC coupled to SCENGEN
developed by the IPCC was used for climate change simulations, since it has an advantage of
having spatially adjusted GCMs. This study was conducted in Lowlands of Lesotho, which is
situated in the western part of Lesotho.
In order to estimate the level of climate change impact on the three main cereal crops in terms of
cropped area and production (sorghum, wheat, and maize), climate change scenarios of
precipitation and temperature were developed for lowlands of Lesotho. Baseline climate was
based on the 29 years-period, 1980-2008 of the mean monthly normal. The two time slices 2030-
2050 and 2080-2100 (near-term and long-term) were chosen. The choice of these time slices was
justified by the availability of demographic projections for the areas at those periods. The A2
(medium-high GHG emission pathway) and B2 (medium-low) were used to produce future
scenarios of the study area. The changes of climate variables were applied to crop simulation
model called CROPWAT to simulate future crop yields. The model was first calibrated. It was
run without taking into account CO2 fertilization effect.
When the two stated emission scenarios were incorporated in the analysis, the comparison
between future scenarios and reference period highlighted higher monthly averages of maximum
temperatures with differences higher than 4-5.8 °C for B2 and A2 at the year 2100. Results also
showed that depending on the level of future emissions, the average seasonal temperature
increase in the study area by the end of the twenty-first century will be higher in winter and
spring between 3 and 5.8 °C. The MAGICC/SCENGEN outputs also in 2100 predicted
significant reductions of the amount of rainfall -27% and - 47% under B2 and A2, respectively,
particularly in spring and summer. Under A2 and B2 most GCMs predicted winter and autumn
precipitation increase. Crop modeling result suggested that under climate change the yield per
hectare for the three crops would fall consistently as temperature rises beyond 2.5°C and rainfall
decrease. The decrease is higher for rainfed maize, as compared to sorghum and wheat since they
have mechanisms to withstand drought conditions during crop maturity stage.
These findings have important implications for Lesotho’s agricultural policy and country
strategies for adapting to climate variability and change. There are several potential adaptation
strategies that may be used to offset the negative impacts of climate change on crop yields. These
include switching to drought-tolerant small grains and cereal varieties, and appropriate
management practices. Small farmers should be helped to combine into big farming units to
increase irrigation efficiency. More research on climate change impacts on crop yields is called
for to generate technologies that equip farmers to adapt to the effects of climate change. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/2438787
- author
- Malebajoa, Maoela
- supervisor
- organization
- year
- 2010
- type
- H2 - Master's Degree (Two Years)
- subject
- keywords
- climate change, A2 and B2 SRES, MAGICC/SCENGEN, CROPWAT, Crop Yields, adaptive measures
- publication/series
- Lunds universitets Naturgeografiska institution - Seminarieuppsatser
- report number
- 198
- language
- English
- id
- 2438787
- date added to LUP
- 2012-04-12 18:02:23
- date last changed
- 2012-04-12 18:02:23
@misc{2438787,
abstract = {{Climate change has emerged as the most prominent of the global environment issues and there is
a need to evaluate its impact on the agriculture. General Circulation Models (GCMs) which are
considered as the most advance tools for estimating future climate change scenarios operate on
coarse resolutions. It is for this reason the climate change model MAGICC coupled to SCENGEN
developed by the IPCC was used for climate change simulations, since it has an advantage of
having spatially adjusted GCMs. This study was conducted in Lowlands of Lesotho, which is
situated in the western part of Lesotho.
In order to estimate the level of climate change impact on the three main cereal crops in terms of
cropped area and production (sorghum, wheat, and maize), climate change scenarios of
precipitation and temperature were developed for lowlands of Lesotho. Baseline climate was
based on the 29 years-period, 1980-2008 of the mean monthly normal. The two time slices 2030-
2050 and 2080-2100 (near-term and long-term) were chosen. The choice of these time slices was
justified by the availability of demographic projections for the areas at those periods. The A2
(medium-high GHG emission pathway) and B2 (medium-low) were used to produce future
scenarios of the study area. The changes of climate variables were applied to crop simulation
model called CROPWAT to simulate future crop yields. The model was first calibrated. It was
run without taking into account CO2 fertilization effect.
When the two stated emission scenarios were incorporated in the analysis, the comparison
between future scenarios and reference period highlighted higher monthly averages of maximum
temperatures with differences higher than 4-5.8 °C for B2 and A2 at the year 2100. Results also
showed that depending on the level of future emissions, the average seasonal temperature
increase in the study area by the end of the twenty-first century will be higher in winter and
spring between 3 and 5.8 °C. The MAGICC/SCENGEN outputs also in 2100 predicted
significant reductions of the amount of rainfall -27% and - 47% under B2 and A2, respectively,
particularly in spring and summer. Under A2 and B2 most GCMs predicted winter and autumn
precipitation increase. Crop modeling result suggested that under climate change the yield per
hectare for the three crops would fall consistently as temperature rises beyond 2.5°C and rainfall
decrease. The decrease is higher for rainfed maize, as compared to sorghum and wheat since they
have mechanisms to withstand drought conditions during crop maturity stage.
These findings have important implications for Lesotho’s agricultural policy and country
strategies for adapting to climate variability and change. There are several potential adaptation
strategies that may be used to offset the negative impacts of climate change on crop yields. These
include switching to drought-tolerant small grains and cereal varieties, and appropriate
management practices. Small farmers should be helped to combine into big farming units to
increase irrigation efficiency. More research on climate change impacts on crop yields is called
for to generate technologies that equip farmers to adapt to the effects of climate change.}},
author = {{Malebajoa, Maoela}},
language = {{eng}},
note = {{Student Paper}},
series = {{Lunds universitets Naturgeografiska institution - Seminarieuppsatser}},
title = {{Climate change impacts on crop yields and adaptive measures for agricultural sector in the lowlands of Lesotho}},
year = {{2010}},
}