The mean warming climate does not have identical impacts everywhere around the globe, but the overall trend is well-defined.
Nationally, warming has been most notable to the west, but you’ll note the warming in Western New York is nothing to sneeze at, except the warming may be responsible for longer ragweed seasons. It should also be apparent there is no part of the lower 48 states that has experienced cooling, though there is a region to the south that has not had much of a change.
Even on a local basis, Buffalo has warmed since 1970.
The impact of warming also puts a hit on nighttime low temperatures.
Again, going back to the allergy sneezers, this correlates to a reduction in widespread killing frosts in October, which is what it takes to get the pollen count down. There is the likelihood of some inland frost Friday night that could help, but the frost appears less likely in areas closer to the lakes. This trend for milder nights extends well into the cold weather season.
In general, our growing season has been lengthening in the mean, with the frost-free time span growing longer since 1970. Of course, none of this data is linear. There are spikey ups and downs from year to year, but you can see the median is definitely warming since 1970.
These longer warm seasons also have effects on timing and intensity of autumn foliage.
There has always been year-to-year variability in foliage quality and timing. Heat stress can delay the onset of color change, but we haven’t had so much of that during our mild September.
Yingying Xie, in her doctoral dissertation at the University at Buffalo, was interviewed by Climate Matters, a data clearinghouse and analysis center. One of the most interesting findings in her work involves northward migration of many tree species as the climate warms to the north. This phenomenon already has been occurring in places such as northern New England and eastern Canada. Due to such species growing farther north, they are likely to suffer from a sunlight deficiency at those latitudes compared to their former more southern locations. That would almost certainly lessen fall color intensity and lead to quicker leaf fall-off. To be sure, these are not the kind of warming-related climate crises such as those tied to rising sea levels and warmer oceans. However, leaf-peeping is a multibillion-dollar ecotourism event in many states, including New York. If there is a more consistent reduction in foliage quality and duration, as is likely later this century, the changes could have a significant tourism impact.
In the meantime for this year, New York State has been reporting favorable foliage progress during this last week. Hopefully, some scattered downpours have not knocked too many leaves off their boughs prematurely. Saturday should be bright and sunny, with cool, crisp air and good visibility. I would guess there will be some good colors farther inland and on the hills.
One other negative to a longer mild season is more longevity for pests, such as ticks and some mosquitoes. So if you and your dogs are taking a nice woodland hike this weekend, it’s still a good idea to check for ticks, and to take Centers for Disease Control-recommended precautions with DEET.
After Friday night’s cold temperatures, it appears we’ll be returning to above-average temperatures most (not all) days for the next two weeks. This means surviving ragweed plants will have more time to plague their victims.