Climate Change Pressures in the 21st Century

This web application, published on Esri's Story Map platform, features three metrics that influence plant growth and survival: 

• Growing Degree Days: Used to describe the season available for plants to grow and mature. It's calculated by average temperature for each day in the year, the average number of degrees above 5°C (41°F) for each day, and these values are summed for all the days of the year. 
• Plant Hardiness Zones: Indicates the winter stress that plants experience due to cold temperatures. These zones are based on the average annual extreme minimum temperatures.
• Heat Zones: Maps areas of potential heat stress for plants and animals, including humans. These heat zones map the number of days per year with a maximum daily temperature ≥30°C (86°F). They indicate a change in "hot" conditions, recognizing that individual species have unique adaptations and abilities to tolerate a wide variety of conditions. 

Each pair of maps compares recent conditions (1980–2009) to potential conditions under a scenario of high greenhouse gas emissions at the end of the century. For each metric, links are provided to additional online maps that provide a visual contrast between two scenarios of potential change (RCPs 4.5 and 8.5), and four different time periods. These scenarios emphasize the variation of possible climate outcomes as a result of human decisions driving emission trajectories through this century.