Scientists have determined the length of the growing season has expanded. In the Northern Hemisphere, the end of the season ranged from Sept. 17 to Nov. 26, reflecting a shift in the season to later in the year.
From 1982 to 1999, the end of the growing season was delayed by 4.3 days and from 2000 to 2008 it was further delayed by 2.3 days.
This represents a long-term trend toward later autumn weather. Global Change Biology reports that to measure the length of the growing season, scientists used vegetative index data collected by satellites.
Capturing this data estimated the “greenness” of growing vegetation from 1982 to 2008. Healthy vegetation absorbs most of the visible light and the index calculates the amount of visible light absorbed by vegetation.