St. Brigid’s day is the 1^st of February and considered the first day of spring. Or that’s what we thought before climate change. Seasons don’t seem the same anymore. Spring comes early now and birds are out-of-sync with the food they need for their young. A hot and dry summer can come before it used to arrive in the past and overstay its welcome. Autumn is running late and melding into winter with warmer temperatures and lots of rain. We get less frosty mornings and snow in winter. What’s happening with our seasonal carousel? By 2100, summers may last nearly half the year, and there could be less than two months of winter.

Childhood memories of the seasons bring up fine summer days swimming in the sea, whereas the sun on a hot summer’s day today has a sting to it that wasn’t there before. Strolling in woods during the colours of autumn was pleasant with the falling leaves, where it is more shortened now. I enjoyed regular snowy winters making snowmen and throwing snowballs. A walk on a fine frosty landscape was invigorating. Spring pushed winter over and the seasonal cycle would begin again. Seasons were more pronounced in my youth with their clear individual characteristics. Now they seem to merge into a continuum from hot summers to a mild non-summer of the other three seasons. The only noticeable change would be trees losing their leaves in autumn and growing them in spring.

Seasons and culture

The change of the seasons is part of our culture. Vivaldi’s Four Seasons is a popular staple in the music canon composed in 1720. They are based on sonnets for the 4 seasons, maybe written by Vivaldi himself, that set out the spirit of each season that his music was intended to evoke. They were a revolution in musical conception: he represented flowing creeks, singing birds (of different species, each specifically characterised), a shepherd and his barking dog, buzzing flies, storms, drunken dancers, hunting parties from both the hunters' and the prey's point of view, frozen landscapes, and warm winter fires.

A favourite artist of mine is Pieter Breughel the Elder, a Flemish painter from the 16th century. He painted various scenes covering different times of the year in five surviving panels. The most famous would be winter (pictured in banner — source: Google Public Domain Arts and Culture), with hunters trudging home in the snow. It is in the Kunsthistorisches Museum in Vienna which I have been lucky to see.

A warming world's impact

Global warming has definitely changed the duration of the seasons. Spring arrives a fortnight earlier on average, and autumn two weeks later. In other words, the vegetation growing season has been lengthened by an average of one month over the last five decades. As the climate warms, summer heat stress could lead to shorter autumn colour displays for many tree species. Heavy storms and rains can physically knock leaves off of trees before they change colour.

How will these changes affect humanity? Scientists predict that longer summers will likely disturb agriculture seasons and the rhythm of species' activities. This includes early flowering of plants and early bird migrations, which could disrupt the structure and function of ecological communities. Warmer winters may also have an impact on crop yields. The insufficient chilling demand for bud dormancy due to milder winters can stunt the growth of plants, resulting in reduced yields and quality.  Some climate skeptics will state that the increased growing season due to more CO₂ in the atmosphere caused by climate change will aid plant growth. This will not happen unfortunately because the extra heat, droughts, storms & floods etc. arising from global heating will trump the theoretical extra vegetation.

However, the seasons may change differently in this part of the world with the AMOC (Atlantic Meridional Overturning Circulation) where melting glaciers in Greenland are impacting the nature of the North Atlantic current that could make our climate much colder. We learned in school that the Gulf Stream makes our climate more favourable than it should be given our northerly latitude. Scientists have warned that this process may happen quicker than thought previously and could come as early as 2050, if action is not taken immediately to reduce greenhouse gases. In addition, Met Eireann has said the weakening of the AMOC is likely to result in further sea level rises around the country. Ireland could experience a temperature drop of 2 to 4 degrees, particularly in winter, along with drier summers. If this happens, it will reverse the scenario above: we will get longer winters alongside curtailed summers. This will have a dramatic negative effect on food production in Ireland and to be avoided if at all possible.

It would be good to return to the regular changing of the seasons in a quarterly cycle. To do this, we will need to turn back the dial on global warming leading to climate weirding, as some climate activists refer to it. See An Taisce’s Professor John Sweeney reporting from COP29. Also check out An Taisce’s own Climate Ambassador programme to learn more about the subject and what one can do to help.

So let’s spring into action, make hay while the sun shines, not fall, and avoid a winter of discontent (and unfortunately much more serious stuff).