c) Below are figures showing estimated changes over 21 st century to mean annual
ID: 291803 • Letter: C
Question
c) Below are figures showing estimated changes over 21st century to mean annual Temp T and mean annual Precip P over all of Africa, based on 2 future greenhouse gaz emission scenarios (RCP8.5 -relatively high emissions maintained- and RCP2.6- CO2 decreases starting in 2040, an optimistic scenario). These maps are extracted from Sections 22.2.1 (on future Temps) and 22.2.2 (on Precip) of Chapter 22 of an IPCC report.Locate Nigeria on these maps and describe the range of values of changes in P and T by 2100 that are predicted based on the scenarios.
(b) Describe the possible effects of these predicted changes in P and mean T on the available water resources to meet the growing food production needs (for crops and for cattle). In your analysis distinguish the climate change effects on so called “blue” water (runoff water in lakes and rivers that could be pumped and used for field irrigation) and on “green” water (which is rainwater naturally falling on soil that can then be transpired by growing plants, in simple “rain fed” agriculture). Based on your understanding of the water budget and hydrology, will each of these 2 types of water sources for food production more likely increase, decrease or stay approx. stable (give separate answers for “blue” and for “green” water). In each case, give your reasoning based on hydrology theory seen in class.
Annual Temperature Difference from 1986-2005 mean 0 mid-21st century late-21st centuryExplanation / Answer
The location of Nigeria is as marked below:
The range of values of changes in P and T by 2100 (late 21st century) that are predicted based on the scenarios are:
Change in temperature (T) in Nigeria by 2100 is 0 to 0.25oC (RCP 2.6 scenario) and 3.75 to 4.25oC (RCP 8.6 scenario).
Change in precipitation (P) in Nigeria by 2100 is 10 to 20% (RCP 2.6 scenario) and 0 to 10% (RCP 8.6 scenario).
Blue water:
Under the RCP 2.6 scenario, the blue water for food production is likely to increase slightly as the temperature do not change much and the precipitation increases. However, under the RCP 8.6 scenario, the blue water for food production will decrease significantly because of the drastic increase in the temperature and the associated evaporation. Also, the demand for drinking water will increase significantly and hence the share for food production will decrease.
Green water:
Under the RCP 2.6 scenario, the green water for food production will increase significantly as the temperature does not change much and the precipitation increases. However, under the RCP 8.6 scenario, the green water for food production will decrease slightly because of the drastic increase in the temperature and the associated evaporation.
Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.