A recent article part of the National Science Foundation's Science, Engineering and Education for Sustainability (SEES) investment highlights urban heat island research by ASU's Central Arizona-Phoenix Long-Term Ecological Research (CAP LTER) and several sustainability scientists. With triple-digit summers, Phoenix is well known for its urban heat island effect—when temperatures in urban cities are significantly higher than rural communities due to the increased use of materials like asphalt and concrete that re-radiate heat. "It's all due to the effects of humans," says Sharon Harlan, a senior sustainability scientist in the Global Institute of Sustainability, an assistant professor in the School of Human Evolution and Social Change, and a researcher in NSF's Coupled Natural and Human Systems grant. "We've modified the surface of the land in ways that retain heat." CAP LTER scientists found that temperatures were significantly lower under tree canopies in green parks—what they call a "microclimate ecosystem service," or what we call shade. This could be a way to counteract the urban heat island effect in cities.