A Decade of Land Surface Warming
How did July land surface temperature change across the world from 2012 to 2023?
This visualization uses NASA MODIS observed satellite data to explore July land surface temperature. It focuses on land surface temperature, not air temperature, and compares July observations across years.
Change in July Land Surface Temperature: 2012 → 2023
Colors are binned: red areas are warmer than they were in 2012, while blue areas are cooler.
Compare Year A and Year B
This side-by-side view shows Year A (baseline), Year B (comparison), and the temperature change between them. Adjust both sliders above to compare any two years directly.
Regional July Land Surface Temperature Trends
Regional averages are calculated using country boundaries where possible. Russia is split into Europe, North Asia, and Arctic Land using latitude and longitude rules, since it spans multiple climate regions.
Write-up
Our final visualization seeks to explore how land surface temperature has changed across the world from 2012 to every following year until 2023. We wanted to see which continents and regions have warmed up or cooled down significantly. The visualization uses a world map overview with sliders to compare a 2012 baseline year to a selected comparison year through 2023. Users can also zoom in on certain regions to get a closer look, and the tooltip shows the region, exact location, temperature, and temperature change at that location. The selected region has a dotted boundary around it to make the highlighted area clear. The map uses darker blue pixels for cooling temperatures and darker red pixels for warming temperatures. In addition to the change view, the map also includes an absolute temperature option so users can see the land surface temperature for a selected year only. Below the main map, we added a side-by-side comparison of the baseline year, selected year, and temperature change, as well as a line graph showing average land surface temperature trends by region over time.
We chose a world map as our primary visualization because our question is mainly geographic. Bar charts and line charts were considered, but they require aggregating data by region, which would lose many location-specific patterns. A diverging red-blue color scale was used because it connects intuitively to temperature change, with red representing warming and blue representing cooling. The year sliders give users direct control over time instead of forcing them to watch a fixed animation. Tooltips provide exact values without cluttering the map, and the dotted region boundary keeps the selected region visually clear. The side-by-side panel and line graph were added to support different levels of analysis, from a global overview to more specific regional trends.
We split ourselves into different roles for the project. One area focused on preprocessing the data because the MODIS files were large and needed to be transformed into a format that could load smoothly on the webpage. Another area focused on the interactive map, including zooming, color coding, map mode, and year controls. The final area focused on the supplementary charts, tooltips, layout, styling, and written explanation. This helped us combine data processing, interaction design, and visual storytelling into one final visualization.