Grass was growing to the end of the year, and the remarkably mild winter, into December, is said by some experts to be indication of the long-predicted change.
I gave the last cut to the lawn just before Christmas. The mower used rarely be seen out after October. Some vegetables grew in the garden up to recently.
EPA-published findings on climate change, including a study led by Dr Alison Donnelly, in Trinity College, show that the warmer Irish climate is changing the seasonal cycle of plant and animal species.
The study found the growing season has been lengthened by up to three weeks for a range of deciduous-tree species at locations including Valentia Observatory. Three weeks is a conservative estimate, and anecdotal evidence suggests it could be much longer.
All of this ‘unseasonality’’ can cause havoc to birds and other animals. Not all species respond to the rise in temperature at the same rate, so there is potential for mismatches in timing. Insects are a primary food for some birds, but if bird and insect arrival do not coincide, problems may occur. On a broader scale, there could be serious implications for nature. This year, swallows stayed around longer than usual — they probably missed their usual departure time, due to higher than usual temperatures.
Dr Donnelly’s study links increasing air temperature, particularly in spring, to the earlier emergence of leaves, which contributes to a longer growing season. Warmer June temperatures led to the earlier emergence of some common moth species, such as the ‘flame carpet moth,’ and their period of activity also increased.
Numerous migrant birds are arriving several weeks earlier now than in the 1960s and ’70s. The whooper swan, a winter visitor, is departing earlier in spring than in the 1970s.
This earlier departure is strongly correlated to average February temperature which, in turn, is an indicator of grass growth, the major food source of this grazing species. The earlier availability of food enables the swans to get in condition for earlier departure.
EPA director general, Laura Burke, says the association’s research projects on climate change set out possible actions to manage its effects, and its impact in Ireland will increase over coming decades.
Valentia Observatory, in Caherciveen, Co Kerry, and the National Botanic Gardens are also providing important information to help us understand the impact of climate change on Ireland’s natural world.