Thresholds

Abstract

Have human activities such as deforestation and urban sprawl, natural resource consumption, and pollution exceeded the capability of the planet to absorb these actions? It does appear that we have exceeded many critical environmental thresholds such as the ocean’s capacity to absorb CO2. As a result, record-breaking increases in local, regional, and global rainfall and temperatures are occurring, and increases in the number, intensity, and frequency of tornadoes and hurricanes are being documented. El Niños are more common and now frequently stretch across the entire Pacific Ocean. Coastal fogs are decreasing in frequency. The polar front is weakening and affecting the frequency and duration of polar vortexes. This begs the question—have we exceeded the earth’s carrying capacity?