Global rainbow distribution under current and future climates

Rainbows contribute to human wellbeing by providing an inspiring connection nature. Because the rainbow is atmospheric optical phenomenon that results from refraction of sunlight rainwater droplets, changes in precipitation and cloud cover due anthropogenic climate forcing will alter distribution. Yet, we lack a basic understanding current spatial distribution rainbows how change might this pattern. To assess affect viewing opportunities, developed global database crowd-sourced photographed rainbows, trained empirical model occurrence, applied present-day three future scenarios. Results suggest average terrestrial location on Earth currently has 117 ± 71 days per year with conditions suitable for rainbows. By 2100, likely generate 4.0–4.9 % net increase mean annual rainbow-days (i.e., at least one rainbow), greatest under highest emission scenario. Around 21–34 land areas lose 66–79 gain rainbow-days, hotspots mainly high-latitude high-elevation regions smaller populations. Our research demonstrates alterations non-tangible environmental attributes could be significant are worthy consideration mitigation.