This blog aims to assess agricultural production and how it
may be impacted due to decrease in water availability imposed by climate
change. Thorton et al (2010) assessed
the agricultural system of Eastern Africa using the Hadley Centre Coupled Model
version 3. This model identifies 3 main
scenarios about how the overall agricultural yield (specifically maize and
beans) is impacted. Firstly, crop yield
will decrease, but farmers will still be able to have some output through specific
processes. Secondly, there will be an increase
in yield production due to the gradual warming caused by climate change for a
certain period of time, until warming would become more excessive. Thirdly, crop yields may decline drastically
which may force substantial changes in agricultural systems. This is likely to occur, as there will be a
shift in rainfall and an intensification of drought periods will occur more
frequently due to climate change impacts.
Moderate yield decrease due to climate change
If there are moderate crop yield declines, due to climate
change impacts, it is expected that agricultural production will decrease by
around 25-40% (Thorton et al 2010). However,
farmers can use more sufficient management processes when growing crops and
adapt to using more drought tolerant crops to resolve this problem (Jones and Thorton 2003). However, it is important
to acknowledge that public investment may be essential in the maintenance of
crop yields. This may be problematic due
to the Sub-Saharan countries being developing countries and not having the
economic ability to provide sufficient machinery to increase crop
production.
Yield Increase due to warming
It is suggested that assuming temperatures increase
gradually agricultural production may benefit, due to having enough water and
more days of sunlight for the crops to prosper (Jones and Thorton 2003). This may influence domestic agricultural
production. Hence a family in the
village of Vilhiga Kenya, may need approximately 250kg of maize per person per
year to sustain themselves.
Unfortunately, this would not be met under normal circumstances. However, if the crop yield increases due to
climate change, they could be producing more crops than needed to sustain
themselves and have surpluses which they can sell for an income (Thorton et al 2010). This may be beneficial as it
increases economic security for farmers.
Nonetheless, this may not last long, for example in Tanzania it is
projected that bean production will increase by 4% until 2030 and decline by 5%
to 2050 due to the average temperatures increasing beyond the threshold of
20-22oC (Thorton et al 2010).
This is likely to occur in all sub-Saharan countries, hence having some
economic benefits for a short period of time and then suffering a decrease of
agricultural yield.
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| Maize in Sub-Saharan Africa Credits: http://www.mainsailmfb.com |
Drastic yield decreases due to intense droughts
Depending on the geology of the area and also the intensity
and frequency of drought events agriculture may decline substantially. The growth of crops and beans may stop
completely and alternative crops that are very drought tolerant, may be adapted
such as sorghum and cassava. Although
these plants are considered very drought tolerant and adaptive to climate
change it is important to acknowledge that rainfall is essential for subsidence
and drought conditions may be so severe that not even these crops may survive
(Thorton et al 2010). Consequently, farmers may adapt to a shift in dependence
in livestock. Farmers may prefer to
grow cattle, sheep or goats for subsidence and an income, as it is more
reliable and not heavily dependent on rainfall events (Giordano 2006).
Use of groundwater
It may be argued that
groundwater is highly available in Sub-Saharan Africa and thus with increasing
climate change impacts there can be a shift of water use from more surface
water and rainfall events to groundwater with increasing climate change
impacts. In many semi-arid and arid
regions of Sub-Saharan Africa (including Eastern Africa), people are highly
reliant on groundwater. However, groundwater
abstraction can be very costly and abstraction may be highly variable on the
geology of the area, as most groundwater is found under hard rock (Giordano 2006). Additionally, applying new modern
technology for agricultural use may be costly.
Hence, due to being developing countries, many farmers will be unable to
buy groundwater pumps for irrigation, unless subsidised by the government or
NGOs (Giordano 2006). Lastly, over half
of the Sub-Saharan African rainfall occurs in 4 main countries: The Democratic
Republic of Congo, The Republic of Congo, Camerron and Nigeria (Giordano 2006). Thus most of groundwater recharge occurs in
this area, allowing for more agriculture to take place in these countries
compared to any other region.
Therefore, it is essential to acknowledge that although groundwater exists
and many countries are highly reliant on aquifers, with an increase in climate
change impacts, it will be harder to take advantage of this resource, due to
geological characteristics, water distribution and high costs.
Thoughts
It is emphasised that some short-term agricultural benefits
may occur with increasing climate change impacts. However, in the long-term there will be high
loses of agricultural production in Eastern Africa. This is problematic due to agriculture being
the main source of food security and also providing high economic
security. I fear the trickle down
effects of a decrease in agricultural yield with increasing climate change
impacts, will lead to malnourishment and a decrease in economic growth and
livelihood. Would you not agree?
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| Livestock in Timbuktu Credits: The Guardian |
Hi Maria! I find this post very intriguing particularly where you highlight a critical debate over short- and long-term effects of climate change on agriculture. I completely agree with the idea. I remember someone saying 'Russia will welcome global warming because it turns their land to be more productive' (though I'm aware that it's just one of the extreme ideas..) Here, I'm wondering what would be a potential solution to encourage people to prepare for the long-term consequence. Perhaps one can introduce a different type of crops to adjust to climate change without declining a yield. Or as you say technical advice & training would help improve crop productivity. But I feel these chnages cannot be easily accepted by local people for dietary preference or fear for being manipulated by outsiders. What do you think would be the best solution to this more human-side challenges?
ReplyDeleteHI Satomi! Thank you for your comment! I think the process of changing agricultural practises for long term climate change would consist of education/ knowledge of the problem, changing the types of crops grown, or using drought tolerant crops and using more efficient machinery to produce their agricultural yields. In regards to if these changes are accepted,this is what my next blog is about. Outlining what are the main methods that persuade farmers to adapt to climatic change. In summary, after some research, the 3 main processes which will persuade farmers to change their agricultural processes include, the degree of their wealth/income, the degree of climatic events being extreme and knowledge on the climate change impacts in the long run. It is already posted, so feel free to look at it if you are interested in a more detailed explanation.
ReplyDeleteBuilding upon Satomi's question, I was wondering what you thought of the possibility of genetically-modified drought tolerant crops in the face of climate change? It's an interesting debate especially for Africa - I imagine a lot of external investment would be required to implement them on a large-scale, but perhaps such technological fixes are some of the only answers left to changing climate?
DeleteHi Shruti! A very interesting question. I believe that when it comes to the survival of human kind and having to decide between gm crops or no crops at all such as the case in Africa, I would choose GM although this may not be the option if someone has many options. Would you not agree? Yes, I also imagine a lot of investment may be needed to be implemented in large-scale, even though large scale agriculture is highly variable depending on various countries and their economic status. However, it may be cheaper to invest in GM drought tolerant crops compared to using new technologies for more sustainable use of water. Nonetheless, all water sustainability methods should be encouraged due to the high climate change impacts that may occur.
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