Weather, Climate, and Volcanoes

Weather, Climate, and Volcanoes

By: Marina Kobasiuk

With the volcanic eruption in Guatemala headlining on the news now, along with the continued fissures in Hawaii, there is considerable talk on the effects of volcanoes on weather and climate. The immediate concerns with local weather is usually related to rain and clouds as precipitation becomes harder to predict with ash helping clouds form. Acid rain can also begin to occur, along with other shorter term conditions that result from large amounts of debris in the air, according to the United States Geological Survey. As sulfuric acid released into the air dissolves into water it creates an acidic precipitation that can impact soil and waterway acidity, or cause gradual erosion of other structures. Dust and ash can also cause volcanic smog which is a major health concern for people near any eruption or downwind of one. This is one of the major concerns in Hawaii due to so much magma interacting with ocean water and producing toxic haze.

Meanwhile in Guatemala it has been pyroclastic flows, a massive cloud of ash, lava, and toxic gases all at intensely high temperatures, that have caused the majority of damage so far. But with these effects also come sediment depositions that enrich soil with nutrients for crops that make farming more viable in certain areas. And even aesthetically, some of the most interesting sunrises and sunsets on record occur in the days and weeks after an eruption as ash interacts with clouds and sunlight.

In the long term, volcanoes are thought to be influencers in shifts in climate. In any kind of eruption lots of gases and physical particles are expelled into the air. While some break down or fall back to the surface eventually, with more violent eruptions some of these particles can reach high levels of the atmosphere and remain for years. Physically dust and ash can prevent sunlight from reaching the planet and cause a cooler environment, but on the opposing side greenhouse gases such as carbon dioxide released by volcanoes can also absorb and emit heat back down to the planet, creating a warming trend. This makes the exact influence of a volcano hard to pin down.

These long term effects are more gradual since a volcano releases a relatively small amount of all of these pollutants due to it being a single isolated event, and the planet is often able to adjust with only moderate shifts. On record there are connections between large scale eruptions and major climate shifts, such as Mount Pinatubo in 1991 and the almost half a degree Celsius drop some regions saw after. So observing these two events happening close together will be difficult, but the effects on the regions local weather and the climate shifts for the coming seasons will be important to watch to see how these changes influence the planet.

Summary: There are two major volcanic events happening currently, so here’s a brief look at weather, climate, and how they relate to eruptions.