Researchers from the University of Cambridge have published a study indicating that the surface temperature cooling effect of volcanic eruptions, a significant element in climate projections, may be underestimated by as much as four times. They found that smaller, more frequent eruptions make a substantial contribution to volcanic cooling effects by releasing sulfur gases into the atmosphere, emphasizing the need for a more accurate representation of all volcanic activities in climate modeling.
The study revealed that conventional climate forecasts might underrate the impact of volcanic eruptions on surface temperature cooling by two to four times. However, the cooling effect does not sufficiently offset the global temperature rise instigated by human activities. Led by the University of Cambridge, the team of scientists posited that smaller eruptions could account for up to half of all sulfur gases released by volcanoes into the atmosphere.
The findings, which were published in the journal Geophysical Research Letters, suggest that refining the depiction of volcanic eruptions of varying magnitudes will enhance the reliability of climate projections.
The eruption of a volcano isn’t something humans can control, but volcanic activity plays a crucial role in the global climate system. Volcanoes emit sulfur gases into the upper atmosphere during an eruption, forming tiny aerosols that reflect sunlight back into space. Large eruptions, such as the 1991 Mount Pinatubo eruption, can single-handedly reduce global temperatures due to the vast volume of aerosols. However, large eruptions occur infrequently, while smaller ones occur every couple of years.
While volcanoes’ impact on the global climate is comparatively minor to the greenhouse gases produced by human activity, first author May Chim, a Ph.D. candidate at the Yusuf Hamied Department of Chemistry, stressed the importance of including them in climate models for accurate future temperature assessments.
Standard climate projections, like those in the Intergovernmental Panel on Climate Change (IPCC) Sixth Assessment Report, underestimate the impacts of small eruptions by assuming that future volcanic activity will be similar to the activity recorded from 1850 to 2014.
Chim and her colleagues from various institutions utilized the most recent ice-core and satellite data to generate 1000 scenarios of future volcanic activity, representing low, medium, and high levels of activity. The team then conducted climate simulations using the UK Earth System Model, finding that current climate projections tend to undervalue future volcanic activity and, consequently, the effects of volcanic eruptions on climate.
In the medium scenario, they discovered that volcanic forcing, the influence of volcanoes on the atmosphere, is underrepresented in climate projections by as much as 50%, largely due to smaller eruptions’ effects.
However, the study underlines that the underestimated cooling effect of volcanoes does not outweigh human-caused carbon emissions. Despite the significant effect of small eruptions, the short-lived presence of volcanic aerosols in the atmosphere means they cannot counter long-term global warming.
Accounting for the effect of volcanoes will help improve the robustness of climate projections. The researchers are now exploring whether future volcanic activity could pose a risk to the recovery of the Antarctic ozone hole and sustain a high level of harmful UV radiation on Earth.
This study was partly funded by the Croucher Foundation and The Cambridge Commonwealth, European & International Trust, the European Union, and the Natural Environment Research Council (NERC), a component of UK Research and Innovation (UKRI).
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Frequently Asked Questions (FAQs) about Volcanic Cooling Underestimation
What does the recent Cambridge study suggest about current climate projections?
The recent study from the University of Cambridge suggests that current climate projections are likely underestimating the cooling effects of volcanic eruptions on Earth’s surface temperature, possibly by up to four times.
How are smaller eruptions significant according to the study?
The study found that smaller, more frequent volcanic eruptions contribute significantly to volcanic cooling effects by emitting sulfur gases into the atmosphere. Even though each small eruption may not have a significant effect individually, collectively, their effect is substantial.
Why are volcanic eruptions important for climate models?
Volcanic eruptions, by emitting sulfur gases into the upper atmosphere that form aerosols, contribute to the cooling of the Earth’s surface. Though their impact is minor compared to human-generated greenhouse gases, including them in climate models is crucial for accurately assessing future temperature changes.
How do current climate projections underestimate the impact of volcanic eruptions?
Current climate projections, like those in the IPCC Sixth Assessment Report, assume that future volcanic activity will be similar to the activity recorded from 1850 to 2014, and don’t adequately account for the impacts of small-magnitude eruptions.
Can the cooling effect of volcanic eruptions offset global warming?
No, despite the significant cooling effects of volcanic eruptions, the researchers stress that this does not compare with human-generated carbon emissions. Volcanic aerosols stay in the atmosphere for a year or two, whereas carbon dioxide stays for much longer. Thus, even with high volcanic activity, global warming cannot be stopped.
More about Volcanic Cooling Underestimation
- University of Cambridge
- Geophysical Research Letters Journal
- IPCC Sixth Assessment Report
- UK Earth System Model
- Mount Pinatubo 1991 Eruption
- UK Research and Innovation (UKRI)
- European Union
- Croucher Foundation
- The Cambridge Commonwealth, European & International Trust
6 comments
wait, do smaller eruptions happen every year? Need to read more about this, interesting stuff!
wow, never knew smaller eruptions could have such a big impact. Really puts things into perspective, doesn’t it?
It’s high time we took these studies seriously. Climate change isn’t waiting for us to catch up! and the volcanoes…they’re not going to save us from ourselves.
Scary stuff! just goes to show how much we still don’t know about our own planet…
Undoubtedly a fascinating read. this kind of research is so critical, especially as we continue to grapple with the complexity of climate change.
so we’re underestimating volcanoes. okay… but what can we do about it? Can’t control when they erupt, right?