Losing the Geomagnetic Shield: A Critical Issue for Space Settlement, a new paper by Philip K. Chapman, has just been published in the NSS Space Settlement Journal.
Abstract. The geomagnetic field seems to be collapsing. This has happened many times in the deep past, but never since civilization began. One implication is that the cost of space settlement will increase substantially if we do not expedite deployment of initial facilities in low Earth orbit. Another implication, less certain but much more damaging, is that the collapse may lead to catastrophic global cooling before the end of this century. We must establish self-sufficient communities off Earth before that happens.