Two German Shepherds kept as pets in Europe or the U.S. use more resources in a year than the average person living in Bangladesh. The world’s richest 500 million people produce half of global carbon dioxide emissions, while the poorest 3 billion emit just 7 percent. Industrial tree-cutting is now responsible for the majority of the 13 million hectares of forest lost to fire or the blade each year — surpassing the smaller-scale footprints of subsistence farmers who leave behind long, narrow swaths of cleared land, so-called “fish bones.”

In fact, urban population growth and agricultural exports drive deforestation more than overall population growth, according to new research from geographer Ruth DeFries of Columbia University and her colleagues. In other words, the increasing urbanization of the developing world — as well as an ongoing increase in consumption in the developed world for products that have an impact on forests, whether furniture, shoe leather, or chicken fed on soy meal — is driving deforestation, rather than containing it as populations leave rural areas to concentrate in booming megalopolises.

So are the world’s environmental ills really a result of the burgeoning number of humans on the planet — growing by more than 150 people a minute and predicted by the United Nations to reach at least 9 billion people by 2050? Or are they more due to the fact that, while human population doubled in the past 50 years, we increased our use of resources fourfold?