CLIM-08 / SPM.A / Research primer
How do historical emissions compare with present vulnerability?
Do countries' positions change when cumulative fossil CO2, current per-capita emissions and present vulnerability are considered separately?
NASA/Kennedy Space Center. Electricity infrastructure at the Discovery Solar Energy Center in Florida in April 2021; energy-system context. Contextual image; not used to estimate a trend. Image credits.
The question
Historical contribution and present exposure need not follow the same distribution. The proposed comparison makes the accounting choices visible before drawing any normative conclusion.
Why it matters
Discussions of responsibility often switch denominators mid-argument; a transparent comparison can separate the measured quantities from judgments about fairness.
The AR6 anchor
AR6 assesses unequal historical emissions contributions and disproportionate impacts on vulnerable communities that contributed least to current climate change (high confidence).
AR6 Synthesis Report (2023) / A.1; A.2; C.5.
Evidence and comparison
- Unit of analysis
- Country-history and country-snapshot; the two time scales remain explicit.
- Baseline and denominator
- Compare cumulative territorial fossil CO2 since 1850 and since 1990. Current per-capita emissions retain their contemporaneous denominator; exclude land-use CO2 from this ranking.
- First descriptive test
- Place cumulative contribution beside vulnerability for a predefined country set, showing absolute emissions and the source's current per-capita measure in separate views.
- Deeper analysis
- Test sensitivity to historical start year, country inclusion and vulnerability components; report rank movement rather than presenting one composite responsibility score.
- Attribution status
- descriptive observation
- Uncertainty
- Historical inventories are revised and vulnerability is a constructed index. Neither supports precise estimates of a country's share of another country's damages.
Principal sources
- Global Carbon Budget
Territorial fossil and industrial CO2; Published per-capita CO2; Country identifiers.
Target 1850-2024 history and latest complete per-capita year; release checks pending. Candidate source; import and publication checks are still required. - ND-GAIN Country Index
Country vulnerability score; Exposure, sensitivity and adaptive-capacity components.
Target 2023 snapshot; coverage and index-version verification pending. Candidate source; import and publication checks are still required.
Alternative explanations
- Historical borders
- Trade-embodied emissions
- Population histories
- Index component overlap
The visual argument
Provisional: labeled country scatterplot with a cumulative-start-year switch; annotate denominator changes and carry the selected country into the component comparison.
- Current per-capita comparison
- Historical-start-year rank movement
- Vulnerability-component profile
- Country-boundary accounting table
What these data do not show
- Fossil territorial CO2 is not total historical climate responsibility.
- Country averages cannot describe within-country inequality or legal liability.
Reproducibility and next release
Plan src/build.mjs, frozen data/raw releases and data/processed/responsibility-vulnerability.csv; test country mappings, cumulative sums, missing histories and rank stability, with source hashes and rights in provenance.
- After approval: responsibility comparison study
- Article and accounting methods
- Responsive figures and exact values
- 16:9 hero and launch copy
- Optional PDF carousel
- Chart exports and compact country CSV