• Energy Research

A complete description of the dataset is given by Jones et al. (2023). Key information is provided below. Background A dataset describing the global warming response to national emissions CO2, CH4 and N2O from fossil and land use sources during 1851-2021. National CO2 emissions data are collated from the Global Carbon Project (Andrew and Peters, 2022; Friedlingstein et al., 2022). National CH4 and N2O emissions data are collated from PRIMAP-hist (HISTTP) (Gütschow et al., 2022). We construct a time series of cumulative CO2-equivalent emissions for each country, gas, and emissions source (fossil or land use). Emissions of CH4 and N2O emissions are related to cumulative CO2-equivalent emissions using the Global Warming Potential (GWP*) approach, with best-estimates of the coefficients taken from the IPCC AR6 (Forster et al., 2021). Warming in response to cumulative CO2-equivalent emissions is estimated using the transient climate response to cumulative carbon emissions (TCRE) approach, with best-estimate value of TCRE taken from the IPCC AR6 (Forster et al., 2021, Canadell et al., 2021). 'Warming' is specifically the change in global mean surface temperature (GMST). The data files provide emissions, cumulative emissions and the GMST response by country, gas (CO2, CH4, N2O or 3-GHG total) and source (fossil emissions, land use emissions or the total). Data records: overview The data records include three comma separated values (.csv) files as described below. All files are in ‘long’ format with one value provided in the Data column for each combination of the categorical variables Year, Country Name, Country ISO3 code, Gas, and Component columns. Component specifies fossil emissions, LULUCF emissions or total emissions of the gas. Gas specifies CO2, CH4, N2O or the three-gas total (labelled 3-GHG). Country ISO3 codes are specifically the unique ISO 3166-1 alpha-3 codes of each country. Data records: specifics EMISSIONS_ANNUAL_1830-2021.csv: Data includes annual emissions of CO2 (Pg CO2 year-1), CH4 (Tg CH4 year-1) and N2O (Tg N2O year-1) during 1830-2021. The Data column provides values for every combination of the categorical variables. EMISSIONS_CUMULATIVE_CO2e100_1851-2021.csv: Data includes the cumulative CO2 equivalent emissions in units Pg CO2-e100 during 1851-2021. The Data column provides values for every combination of the categorical variables. GMST_response_1851-2021.csv: Data includes the change in global mean surface temperature (GMST) due to emissions of the three gases during 1851-2021 in units °C. The Data column provides values for every combination of the categorical variables. Accompanying Code Code is available at: https://github.com/jonesmattw/National_Warming_Contributions . The code requires Input.zip to run (see README at the GitHub link). Further info: Country Groupings We also provide estimates of the contributions of various country groupings as defined by the UNFCCC: Annex I countries (number of countries, n = 42) Annex II countries (n = 23) economies in transition (EITs; n = 15) the least developed countries (LDCs; n = 47) the like-minded developing countries (LMDC; n = 24). And other country groupings: the organisation for economic co-operation and development (OECD; n = 38) the European Union (EU27 post-Brexit) the Brazil, South Africa, India and China (BASIC) group. See COUNTRY_GROUPINGS.xlsx for the lists of countries in each group. {"references": ["Jones, M. W. et al. National contributions to climate change due to historical emissions of carbon dioxide, methane and nitrous oxide, Sci. Data (2023)", "Andrew, R. M. & Peters, G. P. The Global Carbon Project's fossil CO2 emissions dataset. (2022) doi:10.5281/zenodo.7215364", "Friedlingstein, P. et al. Global Carbon Budget 2022. Earth Syst. Sci. Data 14, 4811\u20134900 (2022).", "G\u00fctschow, J. & Pfl\u00fcger, M. The PRIMAP-hist national historical emissions time series (1750-2021) v2.4. (2022) doi:10.5281/zenodo.7179775.", "Forster, P. et al. The Earth's Energy Budget, Climate Feedbacks, and Climate Sensitivity. In: Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [Masson-Delmotte, V., P. Zhai, A. Pirani, S. L. Connors, C. P\u00e9an, S. Berger, N. Caud, Y. Chen, L. Goldfarb, M. I. Gomis, M. Huang, K. Leitzell, E. Lonnoy, J.B.R. Matthews, T. K. Maycock, T. Waterfield, O. Yelek\u00e7i, R. Yu and B. Zhou (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, pp. 923\u20131054, doi:10.1017/9781009157896.009. (2021).", "Canadell, J. G. et al. Global Carbon and other Biogeochemical Cycles and Feedbacks. In: Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [Masson-Delmotte, V., P. Zhai, A. Pirani, S. L. Connors, C. P\u00e9an, S. Berger, N. Caud, Y. Chen, L. Goldfarb, M. I. Gomis, M. Huang, K. Leitzell, E. Lonnoy, J.B.R. Matthews, T. K. Maycock, T. Waterfield, O. Yelek\u00e7i, R. Yu and B. Zhou (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, pp. 673\u2013816, doi: 10.1017/9781009157896.007. (2021)."]} This work was principally funded by the European Commission Horizon 2020 (H2020) VERIFY project (no. 776810). M.W.J. further acknowledges the support of the UK Natural Environment Research Council (NERC; no. NE/V01417X/1). G.P.P. further acknowledges the support of the H2020 4C project (no. 821003) and the H2020 PARIS REINFORCE project (no. 820846). R.M.A. further acknowledges the support of the H2020 4C project (no. 821003). T.G. was funded by the H2020 ESM2025 project (no. 101003536). P.F. was funded by the H2020 4C project (no. 821003). C.L.Q. was funded by the UK Royal Society (grant no. RP\R1\191063).

Abstract The year 2022 saw record breaking temperatures in Europe during both summer and fall. Close to 30% of the European continent was under severe summer drought with a similarly large area affected (3.0 million km2) as during the recent 2018 drought, but now located in central and southeastern Europe. Multiple sets of observations suggest a reduction of net ecosystem carbon exchange in summer (57-62 TgC) over this area, and specific sites in France even showed a widespread summertime carbon release by forests, as well as wildfires. A warm fall with prolonged carbon uptake offered only partial compensation (up to 32%) for the carbon uptake lost due to drought. This severity of this second drought event in 5 years suggests these impacts to no longer be exceptional, and important to factor into Europe's developing plans for net-zero greenhouse gas emissions that rely on carbon sequestration by forests.

We analysed gross primary productivity (GPP), total ecosystem respiration (TER) and the resulting net ecosystem exchange (NEE) of carbon dioxide (CO2) by the terrestrial biosphere during the summer of 2018 through observed changes across the Integrated Carbon Observation System (ICOS) network, through biosphere and inverse modelling, and through remote sensing. Highly correlated yet independently-derived reductions in productivity from sun-induced fluorescence, vegetative near-infrared reflectance, and GPP simulated by the Simple Biosphere model version 4 (SiB4) suggest a 130–340 TgC GPP reduction in July–August–September (JAS) of 2018. This occurs over an area of 1.6 × 106km2with anomalously low precipitation in northwestern and central Europe. In this drought-affected area, reduced GPP, TER, NEE and soil moisture at ICOS ecosystem sites are reproduced satisfactorily by the SiB4 model. We found that, in contrast to the preceding 5 years, low soil moisture is the main stress factor across the affected area. SiB4’s NEE reduction by 57 TgC for JAS coincides with anomalously high atmospheric CO2observations in 2018, and this is closely matched by the NEE anomaly derived by CarbonTracker Europe (52 to 83 TgC). Increased NEE during the spring (May–June) of 2018 (SiB4 −52 TgC; CTE −46 to −55 TgC) largely offset this loss, as ecosystems took advantage of favourable growth conditions.This article is part of the theme issue ‘Impacts of the 2018 severe drought and heatwave in Europe: from site to continental scale’.

Abstract. Regional land carbon budgets provide insights on the spatial distribution of the land uptake of atmospheric carbon dioxide, and can be used to evaluate carbon cycle models and to define baselines for land-based additional mitigation efforts. The scientific community has been involved in providing observation-based estimates of regional carbon budgets either by downscaling atmospheric CO2 observations into surface fluxes with atmospheric inversions, by using inventories of carbon stock changes in terrestrial ecosystems, by upscaling local field observations such as flux towers with gridded climate and remote sensing fields or by integrating data-driven or process-oriented terrestrial carbon cycle models. The first coordinated attempt to collect regional carbon budgets for nine regions covering the entire globe in the RECCAP-1 project has delivered estimates for the decade 2000–2009, but these budgets were not comparable between regions, due to different definitions and component fluxes reported or omitted. The recent recognition of lateral fluxes of carbon by human activities and rivers, that connect CO2 uptake in one area with its release in another also requires better definition and protocols to reach harmonized regional budgets that can be summed up to the globe and compared with the atmospheric CO2 growth rate and inversion results. In this study, for the international initiative RECCAP-2 coordinated by the Global Carbon Project, which aims as an update of regional carbon budgets over the last two decades based on observations, for 10 regions covering the globe, with a better harmonization that the precursor project, we provide recommendations for using atmospheric inversions results to match bottom-up carbon accounting and models, and we define the different component fluxes of the net land atmosphere carbon exchange that should be reported by each research group in charge of each region. Special attention is given to lateral fluxes, inland water fluxes and land use fluxes.

AbstractIn the framework of the RECCAP2 initiative, we present the greenhouse gas (GHG) and carbon (C) budget of Europe. For the decade of the 2010s, we present a bottom‐up (BU) estimate of GHG net‐emissions of 3.9 Pg CO2‐eq. yr−1 (using a global warming potential on a 100 years horizon), which are largely dominated by fossil fuel emissions. In this decade, terrestrial ecosystems acted as a net GHG sink of 0.9 Pg CO2‐eq. yr−1, dominated by a CO2 sink that was partially counterbalanced by net emissions of CH4 and N2O. For CH4 and N2O, we find good agreement between BU and top‐down (TD) estimates from atmospheric inversions. However, our BU land CO2 sink is significantly higher than the TD estimates. We further show that decadal averages of GHG net‐emissions have declined by 1.2 Pg CO2‐eq. yr−1 since the 1990s, mainly due to a reduction in fossil fuel emissions. In addition, based on both data driven BU and TD estimates, we also find that the land CO2 sink has weakened over the past two decades. A large part of the European CO2 and C sinks is located in Northern Europe. At the same time, we find a decreasing trend in sink strength in Scandinavia, which can be attributed to an increase in forest management intensity. These are partly offset by increasing CO2 sinks in parts of Eastern Europe and Northern Spain, attributed in part to land use change. Extensive regions of high CH4 and N2O emissions are mainly attributed to agricultural activities and are found in Belgium, the Netherlands and the southern UK. We further analyzed interannual variability in the GHG budgets. The drought year of 2003 shows the highest net‐emissions of CO2 and of all GHGs combined.

AbstractThe year 2022 saw record breaking temperatures in Europe during both summer and fall. Similar to the recent 2018 drought, close to 30% (3.0 million km2) of the European continent was under severe summer drought. In 2022, the drought was located in central and southeastern Europe, contrasting the Northern-centered 2018 drought. We show, using multiple sets of observations, a reduction of net biospheric carbon uptake in summer (56-62 TgC) over the drought area. Specific sites in France even showed a widespread summertime carbon release by forests, additional to wildfires. Partial compensation (32%) for the decreased carbon uptake due to drought was offered by a warm autumn with prolonged biospheric carbon uptake. The severity of this second drought event in 5 years suggests drought-induced reduced carbon uptake to no longer be exceptional, and important to factor into Europe’s developing plans for net-zero greenhouse gas emissions that rely on carbon uptake by forests.