Scientists concerned: “this is an anomaly”
Almost all of the climate-cooling volcanic eruptions of the past correlate with low solar activity. Worryingly, the Sun is currently going through its deepest solar minimum of the past 100+ years and, looking forward, NASA has revealed the next cycle (25) could be “the weakest of the past 200 years” — a return to Dalton Minimum conditions.
The Dalton Minimum (1790-1830) was a period of historically low solar activity that also included the famine-inducing eruption of Mt. Tambora, in 1815.
Tambora’s eruption was one of Earth’s most powerful of the past 2,000 years, and it compounded the terrestrial cooling already occurring due to low solar activity. This unfortunate combination resulted in some of the harshest climatic conditions of the modern era — 1816 is also known as “the year without a summer”.
See which volcanoes have scientists concerned (this is worthwhile reading; a very informative article):
Thanks to Jimmy Walter for this link