Climate Change

Author: Michael Viney

Each spring the trees around Ireland ease slowly into growth – almost invisibly at first, as the tight winter leaf-buds begin to swell on bare twigs. Then comes the first haze of greening as buds release their first pair of leaves. And after another few days, clusters of four leaves start to fan into the sunlight.

The actual dates when their leaves unfold are different from year to year, depending on the spring weather. But averaged out, trees in Ireland are already greening earlier compared with 30 years ago – some species as much as 30 days earlier. Migrant swallows and house martins are arriving a week earlier from Africa. Warmth-loving insects are spreading north from Europe. Irish nature and biodiversity, like those of countries across the world, are responding to climate change.

Climate, of course, is not the same as weather. Weather is what sails in from the Atlantic horizon from one hour to the next, its cloudy armada a creation of transient temperature, pressure, water content, wind movement and so on. Geography books used to say that it took at least 30 years of weather records to fix the norms and extremes of a region. Some of Ireland’s records go back more than a century. They show storms, blizzards and heatwaves, but their averages settle for the generally moist, mild (but cool) and comfortable Irish climate that we’ve been used to. It seemed guaranteed – timelessly, as most of us thought - by our position at the furthest swirl of the Gulf Stream. Ireland’s natural world, too, had reassuring, seasonal rhythms of its own.

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