A network of interdisciplinary scholars studying past climate change
Average global temperatures fluctuate in response to many different influences, and while some of these “forcings” are now affected by humans, others are shaped entirely by natural causes. Articles on this website have considered whether sulfur released into the atmosphere by volcanic eruptions stimulated the prolonged cooling of the so-called Little Ice Age in the centuries before 1850. Deposited in the stratosphere, volcanic sulfur dioxide interacts with other chemicals to form sulfuric acid and water, which in turn reflects solar radiation. Other articles on the site have introduced research revealing that the reflective properties of man made aerosol pollution in the twentieth century likely sheltered swaths of North America and, later, parts of China from the influence of global warming. Published in the journal Geophysical Research Letters, a new study by lead author Ryan Neely explores how these very different influences have recently interacted with the most important forcing agent of our time: the rapid rise of atmospheric greenhouse gases caused by human activity. Read more.