As humanity reckons with several problems here on Earth, like – war, political turmoil, and an ongoing pandemic, all alongside the energy, climate, and water crises, it’s crucial to remember just how brutal the Universe can be. While earthquakes, volcanoes, tornadoes, hurricanes, and natural disasters haven’t ceased, there’s an imminent threat for which we’re unprepared- a solar storm. Without any mitigations, extensive electrical fires and power station downfalls could come with destructions costing trillions of dollars, impacting the lives of billions.
In our past, the largest recorded solar event occurred in 1859: the Carrington event. However, a more powerful cosmic event struck Earth more than a millennium before that. We know this because, at that time, spanning 774-775, there was an enormous spike in the presence of carbon-14 in Earth’s atmosphere, and the information is found in tree rings all over the world.
In July 2012, the most significant solar eruption since 1859 took place, with inherent properties identical to the Carrington event. Fortunately, the ejecta skipped Earth as the Sun swirled out of position. If the explosion had occurred nine days prior, it would probably have resulted in the most expensive natural disaster in human history.
However, what’s still unclear is how it’s possible to reconstruct what happened more than 1000 years ago when solar storms had no adverse consequences for humanity. Solar astronomy was an almost non-existent science, and what was once only guesswork abruptly became a scientific detective story because of an unlikely witness: ancient cedar trees.