In June and early July 2019, a heat wave in Alaska broke temperature records, as seen in this July 8 air temperature map (left). The image from the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument shows smoke from lightening-triggered wildfires. NASA link
Our study sites in the Sierra Nevada Mountains of California burned in the intense crown fires of 2020. In 2021, they burned again. These stands are adapted to surface fire, but they will not recover from these intense crown fires.
Also in the summer of 2021, we were sampling along the west coast of Greece, when the island of Evia was consumed in a fire that burned for a week down to the city limit of Athens. The summer of 2022 was the largest wildfire year in France.
These maps appeared this week in the NY Times, showing record rainfall and persistent drought in California. NY Times link.
Just within the last two years, catastrophic wildfires in many parts of the world have highlighted connections between climate change and extreme events. Massive floods have wrecked infrastructure at Yellowstone National Park, the central coast of California, Huston, northern Europe, and Pakistan. Heat waves and blizzards have become common. The big questions now concern where these trends will lead.
For today
Today we will first discuss questions and issues that arose with computation. We will follow with an internet research for science and attitudes behind extreme events. Slow changes attributed to human-caused climate change include increasing air temperatures, melting alpine glaciers and polar ice caps, disappearing sea ice, rising sea level, and acidifying oceans. Extreme events include heat waves, drought, flooding, and extreme low temperatures. Today we’ll examine how they are linked. Consider the following questions:
- How are slow changes linked to extreme events like floods and blizzards.
- Can we anticipate extreme events? If not, why not?
- There has been substantial discussion in the media on whether or not a given event is “caused by global warming”. Is this a question worth asking? Why or why not?
Today you can organize within groups and begin research on these questions. A few resources to consider:
The Drought Monitor. National maps are updated weekly to monthly, integrating many sources of information. From the National Drought Mitigation Center.
Climate Central translates scientific findings for a general audience. Look through their “climate shift index”.
Effects of Drought on Forests and Rangelands in the United States: A Comprehensive Science Synthesis. An interagency synthesis of the effects happening now and where they are taking us.
Extreme weather and climate change, includes economic impacts of climate change, with a section on extreme events.
Background for next time
Summarize your research before next meeting as the basis for a group report on how global warming is linked to extreme events. You may consider all types of extreme events, including those that were covered in the Hsiang et al. article. You can use this class meeting to organize your research within the group.
From the summaries, your group will prepare up to two pages describing i) how global warming contributes to extreme climate events and ii) how public opinion has been influenced by increasing extreme events. Your internet search will locate current extremes and why they are happening. Include at least two scientific articles, with citations. Include with these summaries definitions for the terms weather and climate.
Submit your summary to Sakai for your working group to access at our next class meeting. You will be using the internet to address the questions above.