Scientists warn that if climate change continues at its current pace, oceans may lose their ability to reduce atmospheric effects from volcanic sulfur and aerosols as they have done in the past. This means that volcanic eruptions in the future may lead to “years without summer,” as occurred in 1815 after the April eruption of Mount Tambora in Indonesia. New research led by the National Center for Atmospheric Research (NCAR) in the US both confirms that specific eruption’s role in altering the global climate and the role that future eruptions might play if the ocean’s temperature continues to be affected by melting sea ice and rising global temperatures.
The researchers used data from Community Earth System Model’s (CESM) Last Millennium Ensemble Project, which provides simulations of Earth’s climate based on the geological record from 850 through 2005, to determine that the Mount Tambora eruption caused a notable cooling event on the global climate. Sulfur dioxide sent into the atmosphere became sulfate particles known as aerosols and reflected light away from the Earth. This resulted in a so-called “year without summer,” in which crops across North America and Europe suffered tremendous losses due to cold temperatures and blocked sunlight.
The oceans played an important role in returning the climate to relative normalcy through a process in which the colder water of the ocean sinks while warmer water rises to the surface, helping to warm the surrounding land and atmosphere. However, due to changing ocean temperatures resulting from climate change, if an eruption similar to Mount Tambora were to occur in 2085, the ocean would be less able to bring about climate stabilization. Study author Otto-Bliesner wrote, “The response of the climate system to the 1815 eruption of Indonesia’s Mount Tambora gives us a perspective on potential surprises for the future, but with the twist that our climate system may respond much differently”.