As human-caused climate change becomes more influential, we can expect to see more extreme responses from our environment. Among these responses is increased volcanic activity.
If conditions in our world remain on their current trajectory, volcanic eruptions are expected to increase over the next few decades. But how exactly does climate change affect volcanic activity?
Volcanoes are unstable weak points in the Earth’s top layer of rock. They form when magma chambers bubble to the surface. It takes a lot of heat and pressure to force molten rock to the surface, which means an eruption can take thousands of years to develop.
When the volcano can no longer maintain pressure, it erupts, sending waves of toxic gases into the air and lava to the surface. Small eruptions are insignificant, but larger ones cause considerable damage.
Volcanoes form at vulnerable points, or “hot spots”, in the Earth’s tectonic plates. Some spots are more susceptible to rashes than others.
Based on this cycle, we can see that changes on the Earth’s surface and below the surface are directly linked. With that in mind, scientists have plenty of evidence to suggest that as the world continues to warm, volcanoes will become more active, which could create a ripple effect of change across the globe.
What Science Says About Increased Volcanic Activity
The evidence for this theory comes mainly from studies conducted by the University of Cambridge and the University of Leeds, both located in England.
The Leeds researchers wanted to understand how the pressure exerted by Earth’s glaciers on the crust affects movements below the surface. This process, known as “surface charging”, can alter the flow of magma and thus lead to increased volcanic activity.
The study, which took place in 2017, looked at the activity of many Icelandic volcanoes 4,500 to 5,500 years ago, when the Earth was still recovering from the last ice age.
Based on the amount of ash deposited in the surrounding area, they concluded that the island’s volcanoes became more active and extreme as the ice melted.
Although not sure of the specifics, the mechanisms behind this phenomenon are simple. Glaciers exert immense pressure on the Earth’s surface, limiting the flow of magma. When glaciers melt, magma can move more freely, bubbling to the surface and erupting more easily.
The Cambridge study, published in 2021, suggests that climate change will transform the cooling effects of volcanic eruptions. As the atmosphere warms, smoke and gases from eruptions will be able to rise higher. The vapors could also travel further, affecting regions on the other side of the world.
The most notable example occurred in 1991 when Mount Pinatubo in the Philippines erupted, sending its gases 30 kilometers (18.6 miles) into the sky. The eruption created global haze and lowered the global temperature by about 0.5 degrees Celsius, or nearly one degree Fahrenheit.
Fortunately, the cooling lasted for two years, but as the weather becomes more extreme, these massive eruptions could have longer lasting effects.
The study also found that smaller-scale eruptions, such as the 2011 Nabro eruption in Eritrea, will not affect the climate as much. Climate change has widened the tropopause (the gap between the stratosphere and the troposphere), putting the stratosphere beyond the reach of small flares. The fumes that remain in the troposphere can be removed by precipitation.
In summary, the two studies in question suggest that 1) glacial melting caused by climate change will increase volcanic activity and 2) a warmer atmosphere caused by climate change will increase the effects of large volcanic eruptions.
The Leeds researchers acknowledged that Iceland’s unique geography and proximity to huge glaciers may have increased the effects, and that the changes may not be as extreme in more stable climates.
However, vulnerable areas of the world with many volcanoes could be in serious danger. They specifically pointed to the following regions: the Pacific Northwest, Southeast Asia, southern South America, as well as the Arctic Circle and Antarctica.
Cambridge scientists believe climate change will increase the cooling effects of volcanic eruptions by up to 15% in coming decades. When we also consider the Leeds scientists’ belief that eruptions will increase, the combined effects could be apocalyptic in scope.
If these studies prove accurate, humanity must prepare by gathering valuable resources. People can do their part, for example by finding a supply of clean water and storing food. They might also consider planting a garden in their backyard and learning basic survival skills.
When it comes to climate change, nothing should be left to chance. We must also meet necessities such as clothing, housing and health care. If humans continue to destroy the climate, we must be prepared for the consequences.
By Jane Marsh. Articles in English