The Impact of Climate Change on Select Ecosystems

Terrestrial and marine environments are experiencing pronounced changes. As species and their ecosystems undergo rising temperatures, varying precipitation patterns and alterations in their chemistry and phenology, there is a great deal of added stress on many organisms. Many species attempting to adapt to a rapidly changing climate are forced to migrate or to become extinct. Forest communities are changing in composition as well as migrating northward. Often, roads, cities, and other forms of development physically impede migration. Some species are not able to migrate at the pace with which their ecosystems are warming. In some forest communities, southern boundaries are migrating northward faster than northern boundaries are migrating northward which decreases the overall size of the forest and the amount of habitat available for the species therein. Some insects, like the pine beetle, thrive in warmer conditions providing significant challenges for their hosts. The oceans are warming, global circulation patterns are weakening, overturning is thwarted as there is greater stratification, and there is increased acidification. Coral reefs and other ecosystems which provide food and shelter for a whole host of other species are bleaching worldwide. The amount of carbon humans add to the atmosphere each year globally continues to climb. Currently, we add approximately 35 gigatons of carbon dioxide (CO2) equivalent to the atmosphere annually, and we have moved from approximately 280 parts per million (ppm) of CO2 prior to the Industrial Revolution to 398 ppm in 2014, which was the hottest year on record. The best atmospheric scientists agree that we should keep temperatures below the tipping point of 2° Celsius (C) in order to avert an ecosystems disaster. The purpose of this paper is to present some of the negative scenarios that have been proposed since researchers first realized that warming was inevitable by comparing early forecasts with the latest impacts.