Cooper and colleagues built a radiocarbon record from New Zealand kauri trees around the Laschamps geomagnetic reversal (about 41,000 years ago) and concluded from modelling that the weak field changed atmospheric ozone and drove global climate and environmental shifts.
As reported in: Cooper, Turney, Palmer et al. (2021). A global environmental crisis 42,000 years ago. Science. doi:10.1126/science.abb8677
Livermore and colleagues report the north magnetic pole sped up between 1990 and 2005 from 0–15 km to 50–60 km per year, crossed the date line in 2017, and is being pulled by two lobes of magnetic flux at the core–mantle boundary under Canada and Siberia.
As reported in: Livermore, Finlay, Bayliff (2020). Recent north magnetic pole acceleration towards Siberia caused by flux lobe elongation. Nature Geoscience. doi:10.1038/s41561-020-0570-9
Finlay and colleagues used satellite data to show the South Atlantic weak-field anomaly continues to grow and weaken, and a secondary minimum has appeared south-west of Africa.
As reported in: Finlay, Kloss, Olsen et al. (2020). The CHAOS-7 geomagnetic field model and observed changes in the South Atlantic Anomaly. Earth, Planets and Space. doi:10.1186/s40623-020-01252-9
Williams showed the Schumann resonance, a global electromagnetic resonance driven by lightning, is a sensitive measure of tropical temperature because lightning rates rise with temperature.
As reported in: Williams (1992). The Schumann Resonance: A Global Tropical Thermometer. Science. doi:10.1126/science.256.5060.1184
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Richard Carrington described a "singular appearance" he saw on the Sun on 1 September 1859, an observation now regarded as the first recorded solar flare.
As reported in: Carrington (1859). Description of a Singular Appearance seen in the Sun on September 1, 1859. Monthly Notices of the Royal Astronomical Society. doi:10.1093/mnras/20.1.13