Tonga's Sources of CO2 Emissions
Key Insights
Two-Part Emissions Story
Tonga's CO2 profile is shaped by two sources: historic land‑use change and, more recently, oil use. Over the full record, land‑use accounts for just over half of cumulative CO2, while nearly all remaining fossil emissions come from oil; coal, gas, and other fossil processes are negligible. These shifts define Tonga's overall warming impact.
Land-Use Reversal To Near Neutral
Land‑use emissions were low and steady through the early 20th century, then surged in the post‑war era, peaking near a quarter of a megatonne in the mid‑1950s. From the late 1950s to around 1990 they declined, flipping from a net source to roughly neutral and occasionally absorbing CO2. Since the 1990s, they have hovered close to zero, varying modestly between small releases and small uptakes.
Oil Combustion Becomes Dominant
Oil emissions stayed minimal through 1970, then grew steadily through the 1970s to mid‑2000s, reaching a little over 0.1 megatonnes. After a brief dip in the early 2010s, they resumed an upward path, approaching about 0.15 megatonnes in recent years-near the series high.
Current Trajectory And Priorities
With oil now the main actively rising source, the current trajectory points upward for fossil emissions while land‑use remains near‑neutral. To bend overall emissions down, Tonga's priority is to curb oil demand in energy, transport, and buildings, while safeguarding land management practices that keep the land sector close to a small sink.
Background
The chart shows a national breakdown by source of the yearly CO2 emissions from human activities and processes expressed in megatonnes. It is critical to know and track the sources of national CO2 emissions in order to understand their individual impacts on climate change.
The sources of human CO2 emissions are
- CO2 From Fossil Fuels and Industry: coal, oil, gas combustion, other fossil processes
- CO2 From Land-Use, Land-Use Change, and Forestry
Coal, oil and gas combustion
Fossil fuel CO2 emissions from the combustion of coal, oil and gas are emitted by processes in electricity generation, transport, industry, and the building sector. All processes can be linked to human activities. Examples include driving cars with combustion engines burning diesel or gas, or electric cars charged by electricity from a power plant that burns coal.
Other fossil processes
Fossil CO2 emissions from other processes include sources like cement manufacturing and production of chemicals and fertilizers. Cement also has an absorption factor highlighted in the absorption breakdown chart.
Land-use change
Human civilization emits CO2 by changing and managing its land. Those emissions come, for example, from deforestation, logging, forest degradation, harvest activities and shifting agriculture cultivation. Land-use change also absorbs considerable amounts of CO2, which is shown in the absorption breakdown chart. Land-use change emits more than it absorbs, so the net effect is still emissions, but less than for coal, oil and gas.
Wikipedia: Greenhouse Gas EmissionsEarth System Science Data: GCP 2020 paper: Section 2.2 Land-use change; Section 2.1 Fossil fuel emissions
IPCC: Annual Report 6, 5.2.1.1 Anthropogenic CO2 emissions
Units and Measures
CO2 emissions are expressed in the total weight in megatonnes per year. 1 Megatonne is equal to 1 million tonnes.
Wikipedia: MegatonneWikipedia: Global warming potential
About the Data
The last available year is 2023. CO2 emissions data is from the Global Carbon Project. It contains national CO2 emissions from fossil sources and land-use change.
The Key Insights paragraph was created using a large language model (LLM) in combination with our data, historic events, and a structured approach for best accuracy by 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.