Summers Could Be Six Months Long In The Northern Hemisphere By 2100, Scientists Warn

As climate, change accelerates and global temperatures continue to rise, changes in the beginning of the seasons could have catastrophic consequences for agriculture, ecology and human health, according to a new study in the Journal of Geophysical Research Letters.

Based on their analysis, the authors predict that if nothing done to curb greenhouse gas emissions, summer could reach half a year by the end of this century, with winter lasting less than two months. Researchers studied changes in the length of looking tufts by looking at historical climatic data from 1952 to 2011 across the Northern Hemisphere. For each year, they detect the onset of summer by calculating the duration with a maximum of 25 percent of the temperature, while the duration of the minimum 25 percent of the temperature defined as winter.

Summer length increased from 78 days to 95 days during the study period, while all other seasons decreased. From 1952 to 2011, the winter lasts from 76 days to 73 days, the autumn from 87 days to 82 days, and the spring from 124 days to 115 days. “Summer are getting shorter and warmer due to global warming,” study author Yuping Guan said in a statement before explaining, “Many studies have already shown that modified seasons pose environmental and health risks.” For example, a long summer will probably bring an extended pollen season, which can exacerbate allergies. While these shifts represent an average across the Northern Hemisphere, some regions have experienced particularly drastic changes.

According to the authors of the study, this trend towards long summers most pronounced in both the Mediterranean and the Tibetan Plateau. As a next step, the team used a series of established climate models to predict how things might progress, depending on how much effort we put into preventing climate change. The results showed that under a “business-like scenario” – which would not change our greenhouse gas emissions – “spring and summer will begin about a month before the end of the century in 2011.” To sum it up, “autumn and winter will begin [about] half a month later, which will occur between [summer] about half a year and winter less than two months between 2100.”

If this happens, the consequences could be far-reaching. In fact, we are seeing a dramatic increase in droughts, wildfires and other disasters because of long-term heatwaves. Meanwhile, in the shortest and warmest winters, the frequency and intensity of storms may increase and this is likely to cause considerable damage to human life. The change in the beginning of the seasons would have been a disaster for agriculture as well, because at the wrong time of the year, crops would bloom, flowers and seeds would flow. 

Similarly, ecosystem systems may well break down if animals and plants get uncoordinated with each other’s annual cycles. Fortunately, initiatives to prevent this scene are underway, including a global agreement to try to keep temperatures between two degrees Celsius above pre-industrial levels. This kind of study really comes home to how much this promise is mounting on success.