Three years ago today, Mount Sinabung, one of Indonesia’s most active volcanoes, unleashed volcanic ash up to 16,400 feet. It has erupted again on multiple occasions since. The searing gases released by volcanoes like Sinabung can have one surprising impact on the planet
Click here to subscribe to The Economist on YouTube: http://econ.trib.al/rWl91R7 Global warming is the biggest long-term threat to our planet. But a source of earth cooling can be found in an unexpected place – a volcanic eruption. Could volcanoes counter climate change? Over 200 years ago, Mount Tamboram a volcano in Indonesia blew its top with such force that over the next year the entire planet cooled by one degree Celsius. That’s a drop in temperature twice as large as the warming of the earth over the past fifty years. And it wasn’t a one-off. More recent eruptions like Mount St. Helens in 1980, El Chichon in 1982, and Mount Pinatubo in 1991 also cooled the earth. So could volcanoes help counter climate change? There’s a few things to bear in mind. It takes a big eruption to create a big cooling effect. That’s because it needs enough explosive force to reach the stratosphere. It’s here, ten miles above the Earth where sulphur dioxide gas from the explosion can mingle with water. This reaction produces particles that reflect sunlight away from the planet and so cools the Earth’s surface. Rapid temperature change shocks the climate. A cooler surface means less evaporation, so less rainfall which can result in disrupted seasons, widespread droughts and crop failures. Large eruptions can kill thousands or lead to murderous tsunamis, and the spewing lava can devastate agriculture and result in famine. So don’t expect volcanoes to solve the problem of climate change. Daily Watch: mind-stretching short films every day of the working week. |
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