Autumn is a transitional season. It is generally a time when the heat of summer fades away and the chill of winter gradually returns. But, as our climate changes, the season is heating up.
Across the contiguous United States, autumn temperatures have increased an average of 2.5°F over the past fifty years, according to Climate Central. The western part of the country has seen the fastest seasonal increase, with Reno, NV warming 7.7°F. Las Vegas, NV, and El Paso, TX have each seen a rise of more than 5°F since 1970.
These warmer temperatures may feel like a summer bonus for some, but they also bring a number of negative impacts. Less frost-free days means the allergy season is extended and disease-carrying pests like mosquitos and ticks are able to live and thrive longer. Warmer temperatures also drive up energy bills, as people with air conditioning units use them longer into the season. This in turn, if they are powered by fossil fuels, adds even more heat-trapping greenhouse gases to the atmosphere.
Wildlife is also feeling the effects of a warming fall. The timing of when fruits ripen, for example, is being skewed from its “normal schedule”. In turn, this is impacting the once well-synced patterns of animal behaviors such as bird migration and hibernation.
Looking ahead, as greenhouse gas emissions continue to increase, so too will the temperature and its associated impacts.