Extreme weather events dominated the news this summer, including reports of massive wildfires in Canada; Dangerous flooding in India, Japan and the eastern United States; intense heat in Spain, China, USA and Mexico; and the hottest day ever recorded on Earth. A recent study by scientists at the Bay Area Environmental Research Institute (BAERI) and NASA Ames Research Center provides a comprehensive analysis of how these extreme events will worsen as our planet’s temperature rises, and where these events will most likely collide and merge. in ways that significantly affect people’s lives and livelihoods.

The study was published in the journal The Future of the World. The study uses NASA Earth eXchange—Global Daily Downscaled Projections (NEX-GDDP), a publicly available NASA dataset that can “upgrade” projected changes to a local scale, allowing any community around the world to start preparing today.

The study looked at a world where warming has exceeded two degrees Celsius compared to pre-industrial times. It focused on geographic patterns in projected changes in key climate variables, including changes in air temperature, precipitation, relative humidity, solar radiation, and wind speed. A two-degree warming is considered the critical threshold at which the Earth will witness the dangerous and cascading effects of human-induced climate change. According to the study, although there are differences in the predictions of different climate models, a two-degree warming is expected in the 2040s.

Climate variables do not act alone. “We wanted to examine how these individual climate variables will change, and what their combined effects might mean for people around the world. Changes in one variable can amplify the impact of another. “We need to look at these together to understand the true impact on human lives,” said Taejin Park, a BAERI researcher and first author of the paper. .

The researchers paid particular attention to two indicators of the impact on the climate. The first is heat stress, or the combined effect of temperature and humidity on the human body. They found that most regions of the world will experience more heat stress in the 2040s compared to the 1950-1979 baseline, while equatorial countries will be affected by more days that are considered extreme (for example, one month of additional days of extreme heat stress for countries). East Africa).

The study also looked at fire weather, another indicator of climate effects. Temperature, precipitation, humidity, wind, etc. showed a global increase in extreme fire weather as measured by combining the variables with the Fire Weather Index, or FWI. Researchers noted extraordinary increases in fire weather in the Amazon (+4.3 FWI), central and western North America (+3.3 FWI), and the Mediterranean (+3.7 FWI). “The escalation of the effects of all the extreme climatic conditions studied can cause significant damage to communities and economies through the resulting fires, floods, landslides and crop shortages,” said Ramakrishna Nemani, a BAERI senior scientist and co-author of the study. Floods and droughts in particular are likely to be “more frequent, more intense, longer, or all three”.

Generating unique climate data using big data

The NEX-GDDP dataset used for this study provides global daily climate projections up to 2100. To create this dataset, the team took projections created by the world’s leading climate models and used advanced statistical techniques to “downscale,” a process that greatly increases spatial resolution. Raw climate model projections provide global daily results for areas roughly 120 by 120 miles (200 by 200 kilometers).

The NEX-GDDP dataset scales to approximately 15 by 15 miles (25 by 25 kilometers), which can help leaders develop targeted climate adaptation and mitigation plans. Downscaling processes often combine daily forecasts with monthly averages, but it’s important to retain daily data to catch extreme events. Park explained that when combined with the monthly average, the few days predicted to be dangerously hot and humid could be lost in the numbers, obscuring the risk to human life.

The study’s findings point to an urgent need for decision-makers to understand the complex climate impacts projected for their regions. The unique regional scale of NEX-GDDP data can help local leaders develop climate adaptation and mitigation plans for their communities.

“Data is only valuable when acted upon, and the true value of NEX-GDDP lies in its potential to drive positive change on a meaningful scale around the world,” said Bridget Thrasher, a partner and lead in NEX-GDDP data development. -author of the study. . Source