NASA says some volcanoes might warm climate, destroy ozone layer; what it means

In what can be termed as a very significant and contradictory suggestion by NASA, flood basalt eruptions or extremely large volcanic eruptions might significantly warm Earth's climate which is already reeling under the climate change effect. Flood basalts are regions where a series of eruptive episodes lasting as long as centuries happen. 

NASA also suggested that it can devastate the ozone layer that shields life from the sun's ultraviolet radiation. UV radiation is a form of non-ionizing radiation that is emitted by the sun. While it has some benefits, including the creation of Vitamin D, it also can cause health risks. What is interesting is that NASA's suggestion is a contradiction to previous studies indicating these volcanoes cool the climate.

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The study titled, 'Volcanic Climate Warming Through Radiative and Dynamical Feedbacks of SO2 Emissions', published in the journal Geophysical Research Letters also suggest that these eruptions may have helped warm the climate on Mars and Venus but that they may have also doomed the long-term habitability of these planets by contributing to water loss. 

Although Mars and Venus may have had oceans of water in the distant past, both are currently very dry. Scientists are investigating how these worlds lost most of their water to became inhospitable for life. Here we try to understand what Scott Guzewich, lead author of the paper explained in a press statement.

What he explained

Volcanic eruptions would emit massive amounts of sulfur dioxide gas. The atmosphere quickly then converts these gas molecules to solid sulfate aerosols. 

These aerosols reflect visible sunlight, which causes the initial cooling effect, but also absorb infrared radiation, which warms the atmosphere.

The researchers also saw a 10,000% increase in stratospheric water vapour, which is a greenhouse gas that emits infrared radiation that warms the planet's surface.

The researchers simulated a four-year-long phase of the Columbia River Basalt (CRB) eruption that occurred between 15 and 17 million years ago in US.

This model predicted the effects of the volcanic eruption on the troposphere and the stratosphere, the different layers of the atmosphere.

Troposphere is the lowest layer of the atmosphere which has most of the water vapour and weather, the stratosphere is the relatively dry and calm next layer.

These Columbia River Basalt (CRB) eruptions were likely a mix of explosive events that sent volcanic material high into the troposphere and lower atmosphere.

The simulation assumed that these explosive events happened four times per year and released about 80% of the eruptions' sulphur dioxide.

The researchers found that there was a net cooling for around two years before a warming effect overwhelmed the cooling.

The circulation of the stratosphere changes in a way that discourages ozone formation. The added water vapour in the stratosphere contributes to the destruction of ozone.

(Inputs from NASA)