Ireland's Historic Contribution to Global Warming Since 1850
Key Insights
Moderate Per Capita Contribution
Ireland's historic warming impact amounts to around 2,400 megatonnes since 1850-well under 0.1% of the global total. On a population‑weighted basis this equates to around 3.5 tonnes per capita per year, a moderate rating. In other words, Ireland's overall contribution is small in global terms, and middling when viewed per person across the long record.
Fossil CO2 Shapes The Trend
Most of the positive warming impact comes from fossil CO2. Emissions rose steadily from the post‑war era, climbed fastest from the mid‑1950s to the early 1990s, and reached their highest levels around the early 2000s before easing since then. Oil use expanded from the 1950s, peaked in the mid‑2000s at roughly the mid‑20s megatonnes, and has declined afterwards. Coal was prominent through much of the 20th century but has fallen sharply since the late 1980s to very low levels today. Gas emerged in the 1970s and has been broadly stable around the low tens of megatonnes since the late 2000s. Land‑use CO2 has varied over time, at points close to balance, and more recently a relatively small source.
Agriculture Drives Non‑CO2 Gases
Agricultural sources dominate non‑CO2 gases. Methane emissions were higher in the late 19th century, eased into mid‑century, rose again through the late 20th century, and have trended down since the early 2000s; the warming impact from methane declined sharply in recent decades, offsetting part of other gases. Nitrous oxide grew from the 1940s to the late 1980s and has since been broadly stable to slightly lower, largely linked to agriculture.
Action Priorities For Ireland
Focus on the largest sources: fossil CO2 (especially oil and gas), agricultural nitrous oxide, and livestock methane. Accelerate the shift from oil by electrifying transport and improving efficiency, continue phasing down coal, and keep gas growth in check with renewables. In agriculture, improve fertilizer and manure management and enhance productivity to reduce emissions intensity while sustaining output.
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 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.
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