Climate Change and Extreme Weather Events: Understanding the Impacts

Overview of Weather Events (Late Winter 2019)

• Historic floods in 14 US states from North Dakota to Louisiana (usually a spring event)
• Severe winter storm in high plains in early spring
• Severe tornado outbreak in Central Plains (April-May): 500+ twisters, 13 deaths, destruction from Texas to Iowa
• Questions arising about the impacts of a warming planet

Importance of the Topic

• Climate change isn’t a future event; it’s happening now
• Impacts food, water systems, health, economy, infrastructure, sports, tourism, ways of life

Scientific Consensus on Global Warming

• Zero debate within the scientific community about global warming
• Instrumental records since 1950; satellites enhancing data
• Information indicates warming from the top of the atmosphere to the bottom of the oceans

Evidence of Warming

• Thousands of weather stations worldwide record temperature, rainfall, and wind
• 2018: Earth’s 4th warmest year on record (after 2015, 2016, 2017)
• Nine of the ten warmest years since 1880 have occurred since 2005
• 2019 on track to be in the top three warmest years

Climate Responses to Heat

• Increase in various extreme weather events
• Higher temperatures leading to more intense, lasting heat waves
• Global increase in extreme rainfall events

Historical Understanding of Climate Change

• 1859: John Tyndall discovered greenhouse gases (CO2, methane, water vapor)
• 1890s: Svante Arrhenius predicted fossil fuel combustion enhancing warming (greenhouse effect)
• Ancient atmospheric bubbles and climate proxies (tree rings, ocean sediments, ice cores) reveal climate patterns
• Consistent theme: CO2 levels correspond with temperature changes

Future Projections

• Continued CO2 emissions to lead to more extreme weather
• Rising seas, melting ice from land and glaciers, and sea ice not reforming
• Various extreme weather events occurring simultaneously

Tools for Awareness and Prediction

• Future Urban Climates Mapper: web app showing future climate of urban areas
• Examples: Washington DC in 2080 akin to northern Mississippi; Miami in 2080 similar to southern Mexico

Regional Impacts of Climate Change

• Western US: worsening droughts, increased wildfire risk, poorer air quality
• Midwest: heavy rains impacting agriculture (crop wiping, interference with planting and harvesting)
• Southern US: increased and prolonged heat

Data and Monitoring

• NASA's 16 satellites monitor various climate aspects (evaporation, water vapor, clouds, ice cover, etc.)
• Natural world's response: earlier greening, arrival of birds, northward shift of species

Effects on Agriculture

• USDA crop planting zone map changes from 1990 to 2015 showing northward shift
• Major risk to food production due to rapid climate shifts
• Potential for climate migration due to extended droughts and other impacts

Global Extreme Weather Examples and Projections

• Record-breaking heatwaves, extreme temperatures in various regions globally
• Growing belief extreme weather events will continue unless greenhouse gas levels are reduced

Call to Action

• Improved global awareness and education about climate change
• Encourage discussions and personal actions to mitigate impact