The roar from the earth: Volcano eruptions and climate change

Stockholm, Sweden

The massive eruption of the submarine volcano in Tonga has marked an unusual beginning for the year 2022, adding another layer of haze to the already problematic world. The more than 20-kilometer-high eruption plume of ash, gas and steam swallowed up the neighboring islands, broke the country’s only undersea cable, and sent tsunami shockwaves all around the globe. Satellite images and GIFs were spread across the internet, along with various doomsday predictions. Even though such theories lack all forms of authenticity, we all have intuitively felt a real “roar” from the earth. However, some other crucial assumptions about climate change were made surrounding this eruption.

Throughout history, some significant eruptions have proved to correlate with climate cooling. One of the best-known examples is the eruption of Mount Tambora in 1815, threw up to 1.5 million cubic kilometers of dust and rock into the air, and caused the average global temperatures to drop by 0.4–0.7 °C, making the year the “year without summer”. After the eruption, opinions such as “volcanic eruptions will change the global climate” and even “benefit from volcanic eruptions can offset the impact of global warming and reduce the pressure on emissions reductions” have also sparked heated discussions.

However, scientists have given a “no” response. Despite its apocalyptic-looking plumes and pyroclastic flows, this eruption has emitted relatively little amount of sulfur dioxide into the atmosphere, which is the key component in blocking solar radiation. In addition, since the level of the Tonga volcanic eruption has not been entirely determined, it is not yet possible to judge the extent of the impact of this eruption on the future climate.

Some further discussions were also provoked from this idea. A question of whether impossible to purposefully “trigger” a volcano or release sulfur dioxide into the atmosphere appeared on the internet. However, without the premise of reducing emissions, only relying on solar radiation intervention will not solve the problem of climate change. In addition, this approach cannot help with the issue of ocean acidification, which may introduce other risks and uncertainties, such as acid rain and precipitation distribution.

Scientists have expressed more concerns over the short-term effects, primarily on air and water pollution due to the eruption spews, which harms both terrestrial and marine ecosystems. Moreover, the released sulfur dioxide may lead to significant acid rain, causing further damage to the local crop production.

The earth seems to be having more and more large-scale earthquakes and volcano activities in recent years. Media have in turn made many speculations about whether the earth has entered an active period of crustal movement. The scientific community does not have a clear conclusion, partially due to the continuing activities of the volcano and the still-in-the-process data acquisition and analysis. A piece of possible good news is that the sunsets in the southern hemisphere will look much prettier with the floating volcanic ash. But more bad news seems to come hard on the heels of good: Besides the risks of more eruptions, the intensification of regional and even global climate anomalies, and the threat to human health, many are concerned that the omicron variant spreading at lightning speeds will also be delivered to Tonga along with the international aids.