Introduction

In an age defined by climate urgency, understanding the geography of carbon emissions is more critical than ever. While conversations often focus on “who emits the most,” it’s equally important to ask: how do countries emit? How efficient are their economies per unit of carbon? And what sectors are driving this burden? In this report, I use three Tableau-based visualizations to map global CO₂ emissions in 2022 from three perspectives: dominant emission sectors, CO₂ per GDP efficiency, and sectoral composition of national footprints.

Context & Methodology

These visualizations are built on data from Our World in Data’s CO₂ and Greenhouse Gas Emissions dataset, a comprehensive, annually updated CSV containing national-level data on emissions by fuel type, sector, per capita metrics, and economic context (GDP). The original dataset includes over 60 columns and over 200 country/regional records per year.

To create the three maps, I followed a structured data cleaning and transformation workflow in Excel:

1. Filtered to the year 2022 to ensure consistency across all visualizations.
2. Removed aggregate regions (e.g: “World”, “Asia”, “High-income countries”) to avoid duplication and bias.
3. Dropped countries with null or zero values in critical fields like co2, gdp, or per-sector emissions.
4. Created new fields for analysis, such as:
   • sector_max (the industry with the largest share of a country’s emissions)
   • co2_per_gdp (carbon efficiency per dollar of GDP)
   • coal_share, oil_share, etc. (industry shares of national emissions)

These transformations were essential to highlight not just absolute quantities but also structural patterns. For instance, China has one of the highest total CO₂ emissions, but when examined per capita or per GDP, the interpretation changes.

Visualization 1: Dominant CO₂ Emission Sector by Country

https://public.tableau.com/views/DominantCOEmissionSectorsbyCountry2022/Sheet1?:language=en-US&:sid=&:redirect=auth&:display_count=n&:origin=viz_share_link

This map shows which sector contributes the largest share of CO₂ emissions in each country. Based on 2022 data from Our World in Data, I calculated the largest contributor to national emissions from coal, oil, gas, cement, flaring, and other industrial sources. Each country is color-coded by its top sector, offering a global overview of energy dependencies.

Main Trend:

• Coal dominates in countries like China, India, and South Africa, pointing to coal-heavy electricity grids.
• Oil leads in the U.S. and Middle Eastern nations, reflecting transportation and extraction-driven economies.
• Gas dominates in high-producing economies like Saudi Arabia, revealing infrastructure tied to fossil fuels.

This map helps reveal the energy identity of each nation and lays a foundation for future explorations into decarbonization strategies.

Visualization 2: CO₂ Emissions per Dollar of GDP

https://public.tableau.com/views/COEmissionsperDollarofGDP2022/Sheet1?:language=en-US&publish=yes&:sid=&:redirect=auth&:display_count=n&:origin=viz_share_link

The second map visualizes carbon efficiency—how many tons of CO₂ are emitted per unit of GDP. This highlights not just how much a country emits, but how much carbon is required to produce economic value.

Main Trend:

• Developed countries like France, Japan, and the UK show low CO₂ per GDP, suggesting cleaner economies and services-led structures.
• Countries like Iran, Kazakhstan, and Mongolia show high CO₂ per GDP, meaning they generate significant pollution relative to economic output.

This visualization moves away from absolute blame and instead encourages global accountability in terms of carbon productivity.

Visualization 3: Sectoral Share of CO₂ Emissions

https://public.tableau.com/views/CoalsShareofNationalCOEmissions2022/Sheet1?:language=en-US&:sid=&:redirect=auth&:display_count=n&:origin=viz_share_link

The third map series examines what percentage of a country’s total emissions comes from each sector. Unlike the first map, which focused only on the leading sector, these maps reveal national emission “recipes.”

Coal-heavy examples:

• China, South Africa, and India have over 50% of emissions from coal.

Oil-heavy economies:

• Saudi Arabia, Kuwait, Venezuela show disproportionate oil-based emissions.

Balanced structures:

• Countries like Germany and the U.K. display more distributed CO₂ sources.

Reflection & Next Steps

While these visualizations clearly reveal key global patterns, some limitations remain:

• Missing annotation: Next iteration will include chart-level annotations for major outliers (e.g: China’s 70% coal share).
• Time series: Expanding this into a multi-year view would show progress (or regress).
• Migration & climate: Future maps may intersect emissions with climate risk or displacement metrics.

In future work, I would like to incorporate policy targets (e.g: Paris Goals) and show where countries are over- or under-shooting their commitments.