The change would likely have far-reaching impacts on agriculture, human health and the environment.
In the 1950s, the Northern Hemisphere experienced four seasons in a predictable pattern. But climate change is now driving dramatic and irregular changes to the length and start dates of the seasons, which may become more extreme in the future.
The researchers used historical daily climate data from 1952 to 2011 to measure changes in the four seasons' length and onset in the Northern Hemisphere.
They defined the start of summer as the onset of temperatures in the hottest 25% during that time period, while winter began with temperatures in the coldest 25%.
The team used established climate change models to predict how seasons will shift in the future.
The study found that, on average, summer grew from 78 to 95 days between 1952 to 2011, while winter shrank from 76 to 73 days.
Spring and autumn also contracted from 124 to 115 days, and 87 to 82 days, respectively.
Accordingly, spring and summer began earlier, while autumn and winter started later.
The Mediterranean region and the Tibetan Plateau experienced the greatest changes to their seasonal cycles.
If these trends continue without any effort to mitigate climate change, the researchers predict that by 2100, winter will last less than two months, and the transitional spring and autumn seasons will shrink further as well.