US Carbon Footprint Map

It seems to be Save the Planet day on Maps Mania. All the best maps today seem to be concerned with raising awareness about global emissions and our carbon footprint. My guess is that last week's UN climate change summit in New York has led to a rise in the global output of environment maps.

Today we've already looked at the Changing Global Emissions Map and the Changing Global Emissions Map, two maps which visualize CO₂ emissions around the world. Now the Cool Climate Network has released a Carbon Footprint Map of the USA.

The Carbon Footprint Map visualizes the average annual household carbon footprint of zip code areas in the United States. On first glance my thoughts were that this heat-map of zip code carbon footprints closely resembled a population density map. This would kind of make sense, assuming that the more people there are in an area then the larger the carbon footprint.

On a second look however you can clearly see that the map doesn't actually mirror population density for the whole of the US. In fact northern zip code areas have a far larger carbon footprint, on average, than those in the south. Again this makes sense if you assume colder areas will require a larger carbon footprint due to an increased need to burn fuel to keep warm.

However, as the authors observe, there is also a clear pattern in large cities, which shows that those living in the center of cities have a lower household carbon footprint than those living in city suburbs. It does appear that city slickers are greener than their suburbanite neighbors.