Habitable Zones & Global Climate: February 2020

Astronomers have found an exoplanet more than twice the size of Earth to be potentially habitable, opening the search for life to planets significantly larger than Earth but smaller than Neptune.

Exoplanets orbiting M dwarfs present a valuable opportunity for their detection and atmospheric characterisation. This is evident from recent inferences of H2O in such atmospheres, including that of the habitable-zone exoplanet K2-18b.

The variability of the spectral solar irradiance (SSI) over the course of the 11-year solar cycle is one of the manifestations of solar magnetic activity. There is a strong evidence that the SSI variability has an effect on the Earth's atmosphere.

Phosphorus is an essential element for all known life, and the global phosphorus cycle is widely believed to be a key factor limiting the extent of Earth's biosphere.

With radii ranging between those of the Earth (1 Rearth) and Neptune (~3.9 Rearth), small planets constitute more than half of the inventory of the 4000-plus exoplanets discovered so far.

The world is waking up to the fact that human-driven carbon emissions are responsible for warming our climate, driving unprecedented changes to ecosystems, and placing us on course for the sixth mass extinction event in Earth's history.