Paul B. Sears was an American ecologist and conservationist.  He was one of the first researchers in his area to study human ecology.

Sears was born in Bucyrus, Ohio in 1891.  He received bachelor's degrees in zoology and economics and went on to obtain a Ph.D from the University of Chicago.  He became a professor of botany, teaching at a number of institutions, including Yale University, where he chaired the graduate program in conservation from 1950-1960.

Sears conducted research on a variety of topics.  Among other things, he studied the effects of humans on plants and the connections between plants and the climate.  In the process,  Sears became one of the first students of human ecology, a field that in his view deserved very serious attention.  Sears was also an advocate of  recycling, seeing the re-use of materials as one of the basic principles of ecology.

Sears was an author as well; his most famous book is Deserts on the March, which was published in 1935.  Here Sears draws attention to the mistakes by farmers that led to the horrific dust storm known as the Dust Bowl.  This book influenced the soil conservation movement.

In general, Sears saw knowledge of the immediate environment as the key to solving ecological problems.  He was President of the Ecological Society of America and earned the Society's "Eminent Ecologist Award".  He died in 1990.