reality, with significant negative impacts across Africa • Adaptation and mitigation strategies are in place to address it, with African countries prioritizing adaptation efforts • African countries also have mitigation options through NDCs where they pledged GHG emission reductions, among others • Assessing GHG budget accurately and in a timely manner is becoming more relevant given the climate variabilities and shots dynamics • Not only granularity is a must to shift from the one size-fits-all to a tailored intervention, but the data also need to be available at a high temporal frequency • In this chapter, we explored methane emissions above African countries using satellite data
in 2023, Africa emitted an average of 1,352.97 ppb of CH4, accounting for -30.43% of global average methane emissions +592 ppb Global average Above average Africa average Country Average concentration of CH4 emitted (ppb) Percentage to global average CH4 concentration Mali 1,354.65 -30.35% Namibia 1,331.14 -31,56 % Niger 1,352.92 -30.44 % Nigeria 1374.89 -29.31 % Global methane concentration up to 2023 (~ 1940 ppb) Africa methane emission level Use cases CH4 concentration and percentages (Source: From WORLD METEOROLOGOGICAL ORGANIZATION, WMO-No. 1347)
Methane emission sources III. Methodology for Measuring Methane Emissions Using Remote Sensing IV. Continental Average Methane Concentration V. Country Average Methane Concentration: Mali, Namibia, Niger, Nigeria VI. Correlation Between CH4 Emissions, LST, and Rainfall Over Cropland VII. Summary
of CH4 (~1945 ppb) is much lower than those of CO2 (~420 000 ppb), CH4 is more effective at absorbing and re-emitting infrared radiation (heat). • CH4 has a relatively short lifetime in the atmosphere of around 12 years • The removal of 1 ton of CH4 corresponds to around 84 to 86 tons of CO2 removals over 20 years and 28 to 34 tons over 100 years (IPCC, 2023) • Global warming potential of CH4 on a mass basis is 25 x that of CO2 over a 100-year time horizon Concentration of CO2 Concentration of CH4 (From WORLD METEOROLOGOGICAL ORGANIZATION, WMO-No. 1347)
with a few removals • The range of removals does not match that of the sources, leading to an imbalance • Therefore, one of the most effective ways to reduce CH4 emissions is to target the sources • But what are the emission levels from those sources in Africa? Source: Global methane cycle schematic from the IPCC 5th Assessment Report (AR5) Working Group I Chapter 6 (Ciais, Sabine et al. 2013).
• Not all layers of Earth’s atmosphere are directly impacted by human (anthropogenic) activities. • The troposphere which extends from the Earth’s surface to 10 km (6 miles) in altitude is the most affected. • The troposphere is, therefore, the layer with the largest concentration of GHGs, such as CH4. Atmospheric layers
TROPOMI measurements principles Source: Lorente et al. J.: Methane retrieved from TROPOMI: improvement of the data product and validation of the first 2 years of measurements, Atmos. Meas. Tech., 14, 665–684, https://doi.org/10.5194/amt-14-665-2021, 2021 • Data provided by TROPOMI are 7 x 7 km2 approximately at NADIR. • TROPOMI is a passive sensor • S5P covers the entire globe daily • Weekly averaged data are publicly available
TROPOMI CH4 data validation Source: Lorente et al. J.: Methane retrieved from TROPOMI: improvement of the data product and validation of the first 2 years of measurements, Atmos. Meas. Tech., 14, 665–684, https://doi.org/10.5194/amt-14-665-2021, 2021
from January 01 to December 31, 2023 • Methane concentrations are higher in regions with abundant wetlands, elevated temperatures, and increased rainfall. • The Data are available at AKADEMIYA2063 for every country since 2018
Cropland Senegal: Average CH4 emissions, LST, and rainfall as a function of time, over cropland areas. • Methane emissions are lower at the peak of rainfall and the lowest point of temperature • Methane emissions reach their peak when a certain amount of water is available, and temperatures are sufficiently high • A decrease in rainfall and an increase in temperature are associated with a rise in methane emissions