Tom Skilling, WGN television meteorologist, gave this report on Facebook today about the volcanic eruption that is ongoing in the Caribbean:

The Caribbean’s La Soufriere Volcano isn’t likely to have the cooling effect of 1991’s mammoth Mount Pinatubo eruption in the Philippines–but it’s released the most sulfur dioxide of any Caribbean volcano of the satellite age. At least that’s the early read on the explosive Caribbean volcano which has sent 20,000 fleeing, contaminated water supplies, destroyed crops and created a humanitarian disaster. The ongoing La Soufriere volcano eruption, which began April 9th on St. Vincent in the Caribbean, has already released more sulfur dioxide into the atmosphere than any Caribbean volcano on record during the satellite era (since the mid and late 1960s). But while it has sent between 0.4 to 0.6 teragrams of the gas into the atmosphere after the opening week of eruptions–a gas which, along with volcanic ash, has been known to produce cooling on a global scale with history’s largest eruptions, the current thinking by experts is that the Caribbean monster is unlikely to cause the kind of cooling that was produced by the mammoth eruption of Mount Pinatubo on the Philippines in 1991–one of the largest eruptions in recorded history. “The current thinking is that a volcano needs to inject at least 5 teragrams of sulfur dioxide into the stratosphere to have measurable climate impacts,” explained Michigan Tech volcanologist Simon Carn. The Pinatubo eruption sent ash and gas 22 miles into the atmosphere and led to planetary cooling of 0.7-deg over the three years which followed. It altered rainfall patterns in Asia. By comparison, satellite estimates of the ash and gas plume with La Soufriere has put the ash cloud at 12 miles—phenomenal , but hardly the 22 miles recorded with Pinatubo. ““The current thinking is that a volcano needs to inject at least 5 teragrams of sulfur dioxide into the stratosphere to have measurable climate impacts,” explained Michigan Tech volcanologist Simon Carn.” Currently there are 45 volcanoes with continuing eruptions across the planet as tallied by a joint effort between the Smithsonian Institution’s Global Volcanism Program and the U.S. Geological Survey . At any given time on Earth, it’s estimated 20 volcanoes are erupting. Here’s a NASA report on the La Soufriere eruption: https://earthobservatory.nasa.gov/images/148190/tracking-la-soufrieres-plume?fbclid=IwAR2kwO8gv9Zn1TxH7qpqMP8QLWJxy-AeUKBj4EQ7DjZ6iBaL7OWtxd-6Nk0

Climatologists watch these eruptions carefully because the biggest tropical eruptions can cause temporary cooling of the earth’s surface that can last for several years. Obviously, this would be of huge interest for farmers because it will affect both the spring and fall frost dates and the growing degree days during the growing season. There is also some research that suggests a large volcanic eruption can help trigger changes in ENSO that can also affect us here in the Southeast, but that is not certain. Here is an article from Climate.gov that discusses that topic: https://www.climate.gov/news-features/blogs/enso/can-volcanic-eruptions-cause-el-ni%C3%B1o-maybe-maybe-not.