By Eric Wiebe, EMG volunteer
I had the pleasure of talking to Dr. Rebecca Ward, a climate scientist in the College of Natural Resources at NC State University, who is currently researching resilience in the face of increasing weather extremes. She had previously given a talk for the Plants, Pest, and Pathogens webinar series on climate change mitigation, and I wanted to follow up with a more in-depth conversation. My hope is that this will be the first of a series of blog posts on the topic of climate change and gardening in NC.
Appropriately, probably the most important theme to emerge from our conversation is the importance of resiliency. The current scientific consensus tells us that North Carolinians should expect a number of long term climate trends that will impact what and how we garden. These include:
- Warming temperatures, including lack of cooling in evening and more extreme heat during the daytime in summer.
- More intense hurricanes.
- Increase wildfire risk.
- More intense precipitation, including during tropical storms and hurricanes.
- More severe droughts.
- Sea level rise and salt water intrusion.
While the last bullet may only pertain to those living in coastal areas of the state, the remainder will affect all gardeners in the state. Looking over this list of climatic shifts, it is important to note that what we see is more extremes in temperature and moisture, and more severe weather events. It is important to remember that climate and weather, though related, are not the same thing. Climate science won’t tell you what the weather will be tomorrow or next week, but it will help us plan for the future. And in the future, what we plant and how we garden will need to emphasize resiliency in the face of these increasing extremes. The actions we need to take are both adaptation in the face of climate change and actions we can take to help mitigate it. The following image demonstrates how temperature has increased over time in North Carolina.
Appropriately, one of the most important things we can do is keep on planting! Increasing temperatures over sustained periods of time means that average night time temperatures continue to rise. Just like humans, plants need to take a break from the heat, and when temperatures stay above 70 at night, they can’t fully recover, leaving them more vulnerable to pests and disease. Increasing urbanization and the accompanying pavement and concrete acts as heat sinks which exacerbates this problem. Planting more can help address heat islands. By planting shade trees and other light absorbing plants, you can help absorb energy from the sun, lower air temperatures through evaporation and transpiration, and block sun from heating up soil and man made surfaces. These same plants can help absorb excess moisture from hard rainfalls, with their root systems helping to stabilize soil and prevent erosion. Plants also use carbon dioxide, a greenhouse gas, as part of photosynthesis.
While plants large and small help mitigate the effects of climate change, they need to be chosen with climate change in mind. This means, increasingly, we should look to plants that do well both with wetter soils and in drier conditions during the summer. We need to recognize that higher temperatures means more moisture in the air and higher prevalence of molds and fungus. Also, with more high wind events from extreme weather, placement of trees and tall shrubs need to account for the potential of physical structure (i.e., house) damage and risk of human injury. With climate change in mind, remember that the tree you plant today needs to not only thrive next year, but 30 years from now in what might be different conditions. Tools like the Climate Toolbox allows you to explore what the future climate projections are.
Climate change can often be hard to wrap your head around. However, there are tangible, practical responses that we as gardeners can take. I’ve explored some ideas here and hope to do more in future posts.
Resources
National Center for Environmental Information. https://www.ncei.noaa.gov/news/weather-vs-climate#:~:text=Whereas%20weather%20refers%20to%20short,regions%20can%20have%20different%20climates.
North Carolina Cooperative Extension. Small scale solutions to eroding streambanks. https://henderson.ces.ncsu.edu/2020/11/small-scale-solutions-to-eroding-streambanks/
U.S. Environmental Protection Agency. (2008). Reducing urban heat islands: Compendium of strategies. Draft. https://www.epa.gov/heat-islands/heat-island-compendium.
The Climate Toolbox. https://climatetoolbox.org/ created by the University of California
Article shortlink: https://wp.me/p2nIr1-3K8