• 06.14.12

Mapping Neighborhoods’ Inequality By Counting Trees From Space

Better-off urban neighborhoods are full of amenities that poorer neighborhoods may lack, but a simple examination of greenery in satellite photos may be the most simple indicator.

Rich urban areas have far more trees than poor areas in the same city. In fact, the difference is so stark, income inequality can be seen from space, notes Tim De Chant on Per Square Mile, his blog covering “density” while humanity is busy making its global transition into a predominately urban species.


Research published a few years ago shows a tight relationship between per capita income and forest cover: The authors publishing in Landscape and Urban Planning found every 1% increase in per capita income increased demand for forest cover by 1.76%. When income dropped by this amount, demand decreased by 1.26%.

The dense tree cover of wealthy Cambridge, MA.

“That’s a pretty tight correlation,” writes De Chant. Rich cities can probably afford more trees–the planting, upkeep and space–while poor cities tend to treat them more as a luxury good. That’s short sighted given the benefits urban forests bring from lower utility bills, crime rates, and chronic stress, to higher property values and better city utilities.

To visualize the problem, De Chant browsed the Google Earth archive to pick out the rich neighborhoods from the poor ones in the same cities based strictly on tree cover. Although anecdotal, the contrast is stark from Boston to Beijing.

In neighboring Somerville, people are less well off, and have fewer trees.

A few cities are working overtime to increase urban tree cover, says De Chant. New York City aims to double the number of its tree count to 1 million, and Chicago has planted over 600,000 in the last 20 years. Washington, D.C. is putting thousands of trees into the ground and putting many up for adoption by its residents.

Yet overcoming the poverty of trees in poor cities, and poorer neighborhoods, will become ever more important as the world’s cities grow to house most of humanity.

About the author

Michael is a science journalist and co-founder of Publet: a platform to build digital publications that work on every device with analytics that drive the bottom line. He writes for FastCompany, The Economist, Foreign Policy and others on science, economics, and the environment.