China faces a dilemma. It is home to 20 percent of the world’s population but only seven percent of the world’s water resources and nine percent of the world’s arable land. At the same time, a rising middle class is demanding more food. Over the last 30 years, China’s meat demand has quadrupled.

The United Nations and the streets of Manhattan are going into global warming saturation mode, from Sunday’s People’s Climate March through the Tuesday climate change summit convened by Secretary General Ban Ki-moon and on through an annual green-energy event called Climate Week.

As global environmental change accelerates, understanding how population dynamics affect the environment is more important than ever. It seems obvious that human-caused climate change has at least something to do with the quadrupling of world population over the last 100 years.

The original version of this article, by Lisa Palmer, appeared on Future Food 2050.

As a boy growing up on the shores of Lake Victoria in Kenya, Harvard international development professor Calestous Juma noticed a thing or two about innovations designed to bring more food into his community. He noticed, for instance, that the fishermen were always tinkering with new ways to trap fish while his father, a carpenter, would build the traps. He also noticed that his grandmother, a peanut grower, and other farmers who grew traditional crops such as sweet potatoes, struggled with ways to increase production beyond simply planting the best quality seeds and tubers.