Canada's Historic Contribution to Global Warming Since 1850
Key Insights
Historic Impact At A Glance
Canada's impact from historic emissions is large-around 85,500 megatonnes-amounting to a little over 2% of the global total. On a population-weighted basis, the historic per capita impact is extremely high, at around 32 tonnes per capita per year. This points to a notable long-run contribution to today's warming and a strong case for leadership in rapid reductions.
Fossil CO2 Drove The Rise
About two-fifths of Canada's warming impact comes from fossil CO2. Emissions ramped up through the 20th century, surged during the post‑war era, and were near 600 megatonnes annually in the early 2000s before easing to just over 500 today. Oil-related CO2 is the single largest slice (roughly a fifth of the total), high but relatively stable since the 1970s and sitting around the mid‑200s per year. Coal CO2 grew earlier in the century, then fell sharply since the early 2000s from roughly 125 to about 30 megatonnes. Gas CO2 climbed steadily from the 1970s to the present, reaching roughly the low‑200s per year.
Land Use Shifts Over Time
CO2 from land use adds a little under two-fifths of the overall impact. It was high through the mid‑20th century-often well over 200 megatonnes per year-then declined from the late 1960s onward. Since the turn of the century, the downward trend has accelerated, bringing recent levels to around 100 megatonnes.
Methane And Other Gases
Methane contributes about 15% of the impact. Emissions rose to roughly 120 megatonnes by the mid‑2000s, then edged down; the warming impact from methane has fallen quickly in that period. Nitrous oxide increased after the war and has been broadly stable since the 1980s at around the low‑40s per year. Fluorinated gases remain a small but gradually rising share, near 20 megatonnes.
Actionable Priorities
Given the extremely high per capita impact, Canada can lead by rapidly cutting fossil CO2-especially from oil, gas, and the remaining coal use-continuing to reduce land‑use CO2, and accelerating methane reductions. Swift progress at home, alongside support for other countries, would meaningfully lower future warming.
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