After a summer of heavy rainfall, many in the United States are looking to enjoy a stark but beautiful change in season and weather. However, as research has shown, climate change may shift many autumn processes in a way that affects humans and the entire natural world.
The rise in average temperatures and humidity over the past few decades has had a significant impact on the way leaves fall during autumn. Higher average temperatures cause delays in leaf aging, which results in a delayed fall season. This is opposed to how lower average temperatures that have been seen in the past will slow the production of chlorophyll and advance aging. Increased humidity and the weather that causes it, however, can have a much greater impact. Heavy wind and rainfall can cause leaves to come off of trees before they even change colors. What’s worse is that an increase in moisture can promote fungal diseases on the leaves of trees and even fall food crops. These diseases cause leaves to turn yellow, develop brown spots, and fall sooner.
In contrast, freezing temperatures during autumn prevent leaves from turning deeper hues like reds and purples. Severe frost can also damage a tree. Decreased moisture in the form of drought and wildfires has additional effects on nature during fall, some of which can be devastating. As is the case with many impacts of climate change, drought advances leaf aging, color change, and leaf drop. As for wildfires, ash from nearby fires can deposit onto leaves. This may hinder photosynthesis as leaves will have less surface area to capture sunlight needed for the process. In extreme cases of wildfires, portions of the forest canopy can be destroyed, overall diminishing the ecosystem.
Additionally, tourism, colloquially named “leaf peepers,” is a major source of revenue for states with the most vibrant fall colors, but this becomes a problem when the falling of leaves becomes more unpredictable with the weather. Many northeastern states are seeing the impact of unusually warm autumns, which could cause them to lose out on a billion-dollar industry that promotes travel just for fall foliage. However, since some travel practices are unsustainable and further damage the environment, it is advised that people are conscious of the way they enjoy nature.
But of course, humans aren’t the only animals feeling the heat when it comes to these new autumnal changes. Short-distance migratory birds have been found to leave later than average. Meanwhile, long-distance birds have been migrating earlier. This makes for a greater span of time in which birds have been migrating; the previous average timeframe for birds to leave was September to November, but warmer temperatures increase the timeline from August until December. The habits of insects have also been changing, with increased reproduction as a result of advanced development. They have also been migrating and hibernating later than in previous years, though this is not a heavily researched topic.
So if the leaves don’t turn those classic fall colors anytime soon, don’t fret; it could just be a sign of the later autumn trend. It’ll never be too late to grab an apple cider donut and enjoy a nice autumn breeze.
