Northern hemisphere summers tend to be extremely disruptive in duration

The climate crisis is affecting our planet to such an extent that summers in the northern hemisphere could last half a year by 2100, scientists have warned.

This does not mean longer days basking in the sun, but dramatic impacts on human health, agriculture and the environment.

While an extended period of mild weather may seem appealing at first, such a dramatic change in seasons has the potential to cause enormous disruption to ecosystems that are often finely balanced in terms of weather and temperature.

From prolonged heat waves and forest fires to changing migration patterns affecting the food chain, the study concludes that if global warming continues at the current rate, the risks to humanity will only worsen over time – and the changes are already happening.

Changes recorded and predicted in the seasons of the northern hemisphere. (Wang et al. 2020, geophysical research letters, AGU)

“Summers are getting longer and hotter, while winters are getting shorter and warmer due to global warming,” says physical oceanographer Yuping Guan of the Chinese Academy of Sciences. “Most often I read non-seasonal weather reports, for example, false springs or May snow etc.”

The researchers looked at historical daily climate data from 1952 to 2011, marking the days with the hottest 25% temperatures in those years as the summer months, and those with the coldest temperatures as the summer months. ‘winter.

Analysis found that summer fell on average from 78 days to 95 days from 1952 to 2011, and winter fell from 76 days to 73 days. Spring and fall also decreased by 9 days and 5 days respectively. While spring and summer gradually started earlier, fall and winter started later.

Next, the team turned to future climate models to predict how these trends might continue into the turn of the century, finding that the northern hemisphere could have a summer that begins in early May and ends in mid- October in 2100.

It’s a potentially dangerous development for all sorts of reasons – it would mean more time with allergenic pollen in the air, for example, and the spread of the spread of disease-carrying tropical mosquitoes, to name just two consequences.

“Numerous studies have already shown that seasonal changes cause significant environmental and health risks,” explains Guan.

Based on data collected since 1952, the Mediterranean region and the Tibetan plateau have seen the most changes in seasonal cycles, but it is unlikely that any part of the globe can escape the spillover effects of climate . change.

As temperatures keep moving upward, we see the world’s weather patterns change beyond the point of no return – and every weather variation impacts the oceans and land below.

If we are to be able to get away from the edge of a planet that is heating up beyond our control, it is important to collect as much data as possible to inform the kind of tough decisions that will be needed.

“This is a good overall starting point for understanding the implications of seasonal change,” says climate scientist Scott Sheridan of Kent State University, who was not involved in the study.

The research was published in Geophysical research letters.