Sierra Leone's Historic Contribution to Global Warming Since 1850
Key Insights
High Per Capita Emissions
Sierra Leone's historic greenhouse gas emissions have resulted in a per capita impact of 5.6 tonnes per year, placing it in the "high" category. This reflects the nation's significant contribution to global warming on a per-person basis. The high per capita emissions are largely driven by land-use changes, particularly deforestation for agriculture and infrastructure development. Events such as the expansion of palm oil plantations in the early 20th century and the construction of the Sierra Leone Government Railway in the late 19th century contributed to increased CO₂ emissions due to deforestation.
Land-Use Changes and Agriculture
The primary driver of Sierra Leone's historic emissions has been land-use changes, particularly deforestation for agriculture. The expansion of rice cultivation in the 1980s and the increase in palm oil plantations in the early 20th century significantly contributed to CO₂ and CH₄ emissions. These activities led to the conversion of forested areas into agricultural land, releasing stored carbon into the atmosphere. Additionally, the anaerobic decomposition of organic matter in flooded rice paddies increased CH₄ emissions, further contributing to the nation's warming impact.
Recent Efforts to Reduce Emissions
In recent years, Sierra Leone has made efforts to reduce its reliance on fossil fuels and decrease emissions. The completion of the Bumbuna Hydroelectric Dam in 2009 and the introduction of renewable energy projects in 2017, including solar and wind power initiatives, have contributed to a reduction in CO₂ emissions. These projects aim to provide cleaner energy sources and reduce the nation's warming impact. The shift towards renewable energy is a positive step in mitigating Sierra Leone's historic emissions and promoting sustainable development.
Background
Historic Per Capita Emissions
Historic per capita emissions are a crucial long-period (since 1850), population-weighted (accounting for changing population size) indicator. It shows the contribution of greenhouse gas emissions of a nation per capita per year to the current warming.
The rating scale is:
- Extremely High: above 10 tonnes per capita per year
- Very High: above 7.5 tonnes
- High: above 5 tonnes
- Moderate: above 2.5 tonnes
- Low: above 0 tonnes
- Negative Emissions: under 0
Historically, we don't expect any nation to reach negative emissions. Current warming, or warming targets, like 1.5 °C and 1.7 °C are all based on the fact that there have been human-induced greenhouse gas emissions and there will be some more. It is clear, however, that some nations have had incredibly high historic contributions per capita.
Total Historic Impact
This is the total amount of CO2, CH4, N2O, and F-Gases emissions of a nation from 1850 till 2023 (last available year in the data) expressed in megatonnes of CO2-equivalents. The gases have different atmospheric lifetimes (decay) and warming effects, for this reason we use the GWP100 (100 year time horizon method) to calculate the global warming potential of N2O and F-Gases to express in CO2-equivalents. For CH4, which is a short-term gas, we use the GWP* method to express the historic impact in CO2-equivalents.
Wikipedia: Global Warming PotentialTotal Historic Share
This is a nation's total historic share of global emissions and its contribution to global warming. It is an indicator of historic responsibility. All nations share the responsibility to ensure that developing nations do not copy and repeat the behavior of nations with high historic greenhouse gas emissions, they should not buy into old unsustainable fossil-fuels-based technology, land-use, and infrastructure, rather foster a sustainable and cleaner development.
About the Data
The last available year in all the emission datasets is 2023. CO2 emissions data is from the Global Carbon Project. It contains national CO2 emissions from fossil sources and land-use change. Emissions from CH4, N2O and F-gases come from the PRIMAP-Hist dataset. It is a rich dataset that combines several published sources to create a historical emissions time series for various greenhouse gases. Population data are also from Global Carbon Project where available, however, for many nations it doesn't have historic population going back to 1850. Those historic gaps are filled with population data from Our World in Data.
The Key Insights paragraph was generated using a large language model (LLM) using a structured approach to improve the accuracy. This included separating the context generation from the interpretation and narrative.
Data Sources
Global Carbon Budget 2024 Global Carbon Budget
Update cycle: yearlyDelay: ~ 10 months after the end of the year. Current year values are estimated and published in November.Credits: Friedlingstein et al., 2024, ESSD. Friedlingstein, P., O'Sullivan, M., Jones, M. W., Andrew, R. M., Hauck, J., Landschützer, P., Le Quéré, C., Li, H., Luijkx, I. T., Olsen, A., Peters, G. P., Peters, W., Pongratz, J., Schwingshackl, C., Sitch, S., Canadell, J. G., Ciais, P., Jackson, R. B., Alin, S. R., Arneth, A., Arora, V., Bates, N. R., Becker, M., Bellouin, N., Berghoff, C. F., Bittig, H. C., Bopp, L., Cadule, P., Campbell, K., Chamberlain, M. A., Chandra, N., Chevallier, F., Chini, L. P., Colligan, T., Decayeux, J., Djeutchouang, L., Dou, X., Duran Rojas, C., Enyo, K., Evans, W., Fay, A., Feely, R. A., Ford, D. J., Foster, A., Gasser, T., Gehlen, M., Gkritzalis, T., Grassi, G., Gregor, L., Gruber, N., Gürses, Ö., Harris, I., Hefner, M., Heinke, J., Hurtt, G. C., Iida, Y., Ilyina, T., Jacobson, A. R., Jain, A., Jarníková, T., Jersild, A., Jiang, F., Jin, Z., Kato, E., Keeling, R. F., Klein Goldewijk, K., Knauer, J., Korsbakken, J. I., Lauvset, S. K., Lefèvre, N., Liu, Z., Liu, J., Ma, L., Maksyutov, S., Marland, G., Mayot, N., McGuire, P., Metzl, N., Monacci, N. M., Morgan, E. J., Nakaoka, S.-I., Neill, C., Niwa, Y., Nützel, T., Olivier, L., Ono, T., Palmer, P. I., Pierrot, D., Qin, Z., Resplandy, L., Roobaert, A., Rosan, T. M., Rödenbeck, C., Schwinger, J., Smallman, T. L., Smith, S., Sospedra-Alfonso, R., Steinhoff, T., Sun, Q., Sutton, A. J., Séférian, R., Takao, S., Tatebe, H., Tian, H., Tilbrook, B., Torres, O., Tourigny, E., Tsujino, H., Tubiello, F., van der Werf, G., Wanninkhof, R., Wang, X., Yang, D., Yang, X., Yu, Z., Yuan, W., Yue, X., Zaehle, S., Zeng, N., and Zeng, J.: Global Carbon Budget 2024, Earth Syst. Sci. Data Discuss. [preprint], https://doi.org/10.5194/essd-2024-519, in review, 2024.
PRIMAP-hist The PRIMAP-hist national historical emissions time series (1750-2023)
Update cycle: Every few monthsDelay: Less than 1 yearCredits: Gütschow, Johannes; Busch, Daniel; Pflüger, Mika (2024): The PRIMAP-hist national historical emissions time series (1750-2023) v2.6. Zenodo.
Our World in Data Population - Our World in Data
Update cycle: YearlyDelay: 7 monthsCredits: HYDE (2023); Gapminder (2022); UN WPP (2024) – with major processing by Our World in Data