Researchers at the University of Texas — Austin Jackson School of the Geosciences have recently conducted a study, featured in the April 22, 2016, edition of Science, hypothesizing that volcanic activity associated with plate tectonic movement is a contributing factor to the global climatic shift to higher temperatures. This study analyzes shifts in the Earth’s baseline climate throughout Earth’s 4.6 billion year existence; the study focuses on long-term shift, not short-term/human-induced climate change. The researchers, using a geomorphological lens to examine climate change shifts concluded, ” periods when volcanoes along continental arcs were more active coincided with warmer, or greenhouse, conditions over the past 720 million years. Conversely,  periods when continental arc volcanos were less active coincided with colder, or icehouse, conditions” (University of Texas at Austin). The research team argues that when crustal collisions occur throughout Earth’s history, the effects of plates colliding can increase Earth’s temperatures, especially collisions that result in volcano formation.

Continental arc systems, the researchers argue, act as reservoir for carbon, until volcanic eruption releases carbon into the atmosphere. Continental arc systems are created by the collision of two tectonic plates and the oceanic plate is subverted by the continental plate, forming a subduction zone where magma mixes with trapped carbon to release carbon dioxide when volcanoes erupt.  The amount of carbon dioxide released and held in the atmosphere “influences Earth’s climate.” The research team compiled over 200 published studies, in addition to their own data, to study the past 720 million years of Earth’s geology. The team constructed a global database cataloging the most recent 720 million years of volcanic activity at the margins of the continental plates. The study also examined other greenhouse gases and sediment basins of eroded volcanic structures in order to improve their model.

In concluding statements, team contributor Brian Horton stated, “the cooler icehouse periods tended to correlate with the assembly of the Earth’s supercontinents, which was a time of diminished continental volcanism. The warmer greenhouse periods correlated with continental breakup, a time of enhanced continental volcanism.” This study is important to physical geography because it is representative of the interconnectedness and interdependence Earth’s systems have with one another. The lithosphere and the atmosphere are not independent of each other, but exogenic processes that occur in one sphere or system of the Earth affects the other system.

Source: https://www.sciencedaily.com/releases/2016/04/160421150056.htm