The Global Greening Inequality Explorer

NDVI Trends Across World Income Groups (2000–2024)
  • Ved Panse (A17713463)
  • Stephanie Anshell (A18503005)
  • Sonali Singh (A18589762)
Interactive
Research Prototype
D3.js

Why Greening Inequality Matters

Context for understanding who benefits from global greening

The Global Greening Inequality Explorer asks a simple question with uncomfortable implications: as the planet greens, who is actually benefiting? Using NDVI (Normalized Difference Vegetation Index) as a satellite-based measure of “greenness,” we aggregate time-series data by World Bank income groups and track how much vegetation has increased relative to a 2000–2005 baseline. Our main visualization shows how high-income, upper-middle-income, and lower-middle-income regions diverge over time, with special attention to the period after the 2015 Paris Agreement. The goal of this explorable explanation is not just to display lines, but to let readers actively compare greening trajectories across income groups and reason about whether a “Greening Wealth Gap” is emerging.

Baseline NDVI Levels (2000–2005)

Absolute greenness across income groups

Global NDVI Change Map (2024)

Visualizing greening patterns across countries
Hover on countries to compare NDVI percent change in 2024.

Initial Prototype Writeup

What have we done so far?

We have designed and implemented the core “hero” visualization for our project: an interactive multi-line chart of NDVI percent change over time, grouped by global income level. Behind the visualization, we constructed and pre-processed an NDVI panel dataset aggregated by income group, including a baseline period and derived percent-change values for each year. The D3 chart already supports smooth curves, per-year interpolation, and hover interactions that surface all three income groups at once, which encourages direct comparison instead of reading each line in isolation. We also built the overall page structure for the explorable explanation, including dedicated sections for trends, inequality metrics (Greening Wealth Gap Index), and climate drivers such as rainfall, so that additional coordinated views can plug into this same narrative. Finally, the site is wired up through GitHub Pages, so the current prototype is fully deployed and ready for iterative refinement rather than existing only as a notebook or mockup.

What will be the most challenging part?

The hardest design problem will be building a linked, multi-view dashboard that stays readable while conveying several layers of inequality at once. We want interactions on the main NDVI trend chart—such as hovering on a year, filtering by income group, or highlighting the post-2015 period—to ripple through other views like a GWGI ribbon, a rainfall–NDVI scatterplot, and a heatmap of greening by income group and year. Coordinating these interactions without overwhelming users will require careful choices about which encodings stay static, which respond to hover, and which should require an explicit click or toggle. Another challenge is maintaining expressiveness and honesty while still telling a compelling story: for example, we must avoid exaggerating differences through misleading axis ranges or color choices, even when we want to emphasize inequality. Balancing narrative emphasis, statistical nuance, and interaction complexity is where most of our design time will go for the final project.