Human Dominated Ecosystems
Agriculture is far-and-away the most extensive land use on planet Earth. Urban areas occupy a very small portion of the Earth’s total land area, but have a disproportionate effect on the global environment. The impacts of cities and agriculture include greenhouse gas emissions, human appropriation of net primary productivity, hypoxic zones in the oceans from fertilizer runoff, increasing soil salinity caused by irrigation, and urban heat islands, to name only a few. Further, both types of land use have tremendous importance to society. Over 50% of the Earth’s population now lives in cities and agricultural land will need to produce more food in the coming decades to support a growing global population. Urban and agricultural systems are both threatened by climate change related changes in the Earth system.
The Land Cover & Surface Climate Group at Boston University is engaged in a variety of projects aimed at improving information and understanding of changes in global urban and agricultural systems. With support from a NASA Earth Systems Science Fellowship, PhD student Meghan Salmon is integrating MODIS data sets and hydrologic models to characterize the magnitude of global irrigation practices. With support from the National Science Foundation’s program in Water, Society and Climate, we are using MODIS and Landsat data to characterize agricultural intensification and extensification in Asia. Most recently, with support from NASA’s Interdisciplinary Research in Earth Science program, we begun developing data sets and models to improve understanding of carbon cycling in and around urban areas by linking remote sensing, in-situ observations, and atmospheric transport models.