COGS 108 — Data Science in Practice | UC San Diego | Winter 2026
This project investigates the Climate Inequality Paradox: the phenomenon where the nations least responsible for climate change suffer its consequences the most. Using three publicly available datasets spanning 2005–2023, we quantify the relationship between CO₂ emissions responsibility and climate disaster vulnerability across 164 countries and 1,932 country-year observations.
Were higher per-capita CO₂ emissions associated with greater climate-related disaster impacts — in the form of higher mortality and reduced GDP growth — for lower-income countries than for higher-income countries between 2005 and 2023?
- 19× Inequality Gap: For every ton of CO₂ a low-income country emits, it suffers nearly 19 times more human disaster loss than a high-income country for the same unit of emission
- Emissions vs. Responsibility: High-income nations emit an average of 11.6 tons CO₂/capita — over 31× more than low-income nations at 0.37 tons
- GDP Suppression: Low-income nations experience a ~2 percentage point GDP growth decline as disaster severity increases, while high-income economies remain essentially flat
- Geographic Concentration: 75% of the top 20 most climate-injustice-affected nations are Low Income or Lower-Middle Income
| Income Group | Avg CO₂ (Tons/Capita) | Avg Deaths per 100k | Avg Inequality Ratio |
|---|---|---|---|
| Low Income | 0.368 | 3.644 | 22.399 |
| Lower-Middle | 1.606 | 9.262 | 7.276 |
| Upper-Middle | 4.427 | 4.463 | 1.537 |
| High Income | 11.623 | 6.228 | 1.207 |
A core contribution of this project is the Inequality Ratio metric:
This normalizes disaster impact against emissions responsibility, enabling apples-to-apples comparison across countries with vastly different economic profiles. Rather than asking "how many people died?", it asks "how many people died per ton of CO₂ that country was responsible for emitting?"
| Dataset | Source | Observations |
|---|---|---|
| CO₂ Emissions Per Capita | Our World in Data | 4,085 country-years |
| Disaster Death Rates | EM-DAT via Our World in Data | 1,966 country-years |
| GDP Per Capita (PPP) | World Bank via Our World in Data | 4,005 country-years |
All three datasets were merged on country code and year, restricted to 2005–2023, and filtered to real countries only (valid ISO 3-letter codes). Final merged dataset: 1,932 observations across 164 countries.
- Exploratory Data Analysis (EDA) across income quartiles defined by
pd.qcuton GDP per capita - Log-log scatter plots to visualize wealth-emissions and wealth-inequality relationships across several orders of magnitude
- Median lines per income group to surface structural patterns robust to individual disaster outliers
- OLS regression on log-scaled axes to quantify the inequality ratio trend
- GDP growth analysis binned by disaster severity quintiles with 95% confidence intervals
- Choropleth mapping via Plotly for geographic visualization of inequality ratios
- Python 3.11
- Pandas — data wrangling and merging
- Seaborn / Matplotlib — static visualizations
- Plotly Express — interactive choropleth map
- NumPy — numerical operations and log transforms
This project was completed as part of COGS 108 at UC San Diego (Winter 2026).
| Author | Contributions |
|---|---|
| Jacob Ortiz | Analysis, Background research, Conceptualization, Data curation, Experimental investigation, Methodology, Project administration, Software, Writing |
| Muhammed Abdalla | Software, Writing — original draft, Writing — review & editing |
| Katherine Chui | Software, Visualization, Writing — review & editing |
| Iha Gadiya | Analysis, Methodology, Visualization, Writing — review & editing |
| Jeanne Lee | Background research, Conceptualization, Analysis, Methodology, Visualization, Writing, Project Administration |
- "Current GHG Levels," NOAA. https://www.climate.gov/ghg/current-levels
- "CO₂ emissions per capita," Our World in Data. https://ourworldindata.org/grapher/co-emissions-per-capita
- "Climate Change," Our World in Data. https://ourworldindata.org/climate-change
- "Global natural disaster death rates," Our World in Data. https://ourworldindata.org/grapher/natural-disaster-death-rates
- "Climate Inequality Report 2023," World Inequality Lab. https://wid.world/wp-content/uploads/2023/01/CBV2023-ClimateInequalityReport-2.pdf
- Diffenbaugh & Burke, "Global warming has increased global economic inequality," PNAS, 2019.
- Zahnow et al., "Climate change inequalities: A systematic review," ScienceDirect, 2025.