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Bad Infographic of Mapping Emissions by Country

by on November 13, 2009

emissions-by-countryThe Center for Public Integrity worked with Stephen Rountree to create an interactive infographic visualizing emissions of various countries, and overlays it as bubbles onto a world map.  However, as datavisualization.ch points out it has some flaws:

The data is plotted as a bubble chart on the wold map which makes it basically easy to read. Unfortunately the interface isn’t right where it would need to be, for example hovering over the same data twice restarts a growing animation that doesn’t convey any obvious information thus slowing down the reading process.

But even more critically is a flaw pointed out by Paul of colorful-data.net.  If you look closely at the map (pictured) and compare the bubbles over Brazil (meaning 1,028) and the EU (5,342), the EU has approximately 5x more emissions than Brazil right?  Well why is the circle so much bigger for EU then, far more than 5x:

Now when I use a bubble chart to compare values, I should remember that every viewer will use the area of the circle as representation of that number, not the radius. Example: the circle of Brazil’s current emmissions should fit about 5 times into the one of the European Union. Visually, this map is simply wrong.

Sometimes it’s not sufficient to make the results mathematically correct, they need to be observationally correct.

Mapping Emissions by Country.