The effect of overgrazing on historical temperature trends

Twentieth century temperature records for a latitudinal band extending from 10°N to 50°N are stratified using a recent UNEP map showing areas affected by overgrazing. Linear trend analysis shows that the overgrazed areas have warmed at a rate of 0.0057 K year −1 while land areas in the latitudinal band not impacted by overgrazing have warmed at a rate of 0.0035 K year −1. The difference in temperature between the two groups has increased at a statistically significant rate over the 1901–1990 time period. While this temperature increase apparently associated with overgrazing may be important locally and regionally, the impact of overgrazing probably accounts for less than 1% of global warming over the same time period.