GISS Lunch Seminar
Speaker: Kelton Minor (Columbia Univ)
Title: Global monitoring of psychosocial and behavioral responses to climate stressors

Abstract:
Global climate change is altering local weather distributions and extremes. The World Health Organization has described climate change as "the biggest global threat to human health" view echoed by the editorial boards of over 200 medical journals. Yet, very little is known about the extent and distribution of the impact of climatic stressors on human behavioral outcomes globally. Can digital data streams from personal sensing and social media provide a tool to track the human impacts of climate hazards on daily life? In this talk, I'll share key insights from two recent planetary natural experiments that utilised new forms of social and behavioral data to resolve part of this "hidden" burden. 

First, linking the textual content of ~8 billion geolocated tweets across 190 countries and 13 languages with daily data on local climate extremes and weather conditions, we show that randomly-timed extreme heat and rainfall events independently, and consistently, worsen human emotional expressions online compared to control days in the same location and time of year. Investigating two extreme events shown to have been made more likely due to human-induced climate change, we present evidence that both the 2021 North American PNW heatwave and the Western European extreme rainfall events amplified negative sentiment and reduced positive sentiment by amounts far greater than the historical average heatwave and extreme precipitation effects observed between 2015 and 2020. Since climate change is shifting the extreme tails of most regional temperature and heavy precipitation distributions rightwards, the impact of more severe extremes on overt emotional states may be quite large, pending further psychosocial adaptation. 

But what drives adverse emotional responses to heat? In our second investigation we explore one possible pathway that is critical for human functioning and emotion regulation: sleep. Drawing on over 10 billion sleep-tracking wristband measurements from 68 countries, we find that warmer-than-usual nighttime temperatures harm human sleep, with effects becoming progressively larger as minimum temperatures increase. We show that these hidden impacts of heat are not distributed equally: the elderly, residents of lower-income countries, females, and those already living in hotter climates are disproportionately impacted. We don't find evidence of short, medium or long-term sleep adaptation, and project that increasing greenhouse gas concentrations will likely erode human sleep globally, and unequally, without further adjustment. These findings provide a behavioral-basis to inform climate change policy and illuminate a specific adaptation target to limit downstream consequences for human health, productivity and society.