Climate change can keep the clippers busy

Another Life: A long succession of rainy days kept the electric hedge-cutter propped in the porch while the fuchsia bushes reached…

Another Life: A long succession of rainy days kept the electric hedge-cutter propped in the porch while the fuchsia bushes reached for the sky and narrowed every path. When at last they were dry enough to barber safely, the midges were in residence and the shearing of long, scarlet stems brought them out in vengeful squadrons.

Soft sheaves of greenery piling up around my knees seemed quite equal to what I'd left on the bushes. How much of this biomass, I wondered, was produced by all that extra CO2 in the atmosphere?

The gas boosts a plant's photosynthesis and helps it to use all the extra rain efficiently. By 2025, the summer accession of weight in much of our vegetation - seedlings and perennials in particular - could be up by almost one-third.

That won't be happening everywhere. Global warming will spread deserts as well as lusher greenery. Even on our small island summer droughts in the east and differing regional temperatures will affect what CO2 does to growth. Meanwhile, a whole branch of fuchsia bells, blooming on the ditch in the early days of June, seemed to offer at least an interim benevolence.

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For the Irish and European scientists who gather in University College Galway next week, climate change can never be far out of mind.

They are attending an international conference - European Vegetation in the 21st Century - hosted by the college but organised by the National Parks and Wildlife Service (formerly Dúchas).

The process has taken 25 years of international research and co-operation and one by-product has been a remarkable Map of the Natural Vegetation of Europe, now the basis of an interactive CD-rom (which will cost you €85 from Germany).

While involved in this research the NPWS senior conservation scientist, John Cross, discovered how few of his European scientist colleagues had ever explored the Irish landscape and how much its special habitats intrigued them. Next week's conference is the result - only the third of its kind in half a century.

After three days of briefings on the island's vegetation, the delegates will be off on a week-long field excursion - Connemara bogs and sand dune machair, the Burren flora, Killarney's mossy oakwoods and so on, all very distinctive and different from Continental landscapes, if much more restricted in species. A pity our bluebell woods have faded - Europe doesn't have those either.

The consequences of climate change hover in uncertainty. Some of these will be straightforwardly physical; in Ireland's case, for example, how will regional changes in rainfall and humidity affect the survival of blanket bog, or the rare ferns and mosses of moist western oakwoods? But others will arise from changes in land use, as much marginal land falls back to nature or is planted with different crops.

Irish species and habitats have already been included in the UK-based Monarch project (Modelling Natural Resource Responses to Climate Change) and the Galway conference will hear some results of its work. But the main topic falls to Prof Mike Jones, the plant ecophysiologist (that's a new one) who holds the chair of botany at TCD.

He has been studying the effects of rising CO2 on our farm and natural grasslands since the 1980s. But he has also taken a special interest in the potential of giant grasses as renewable energy sources.

This spring, in a minor fit of landscaping, I tracked down some perennial ornamental grasses on the internet to make tall, fountainy clumps and a bit of autumn colour at strategic corners of the garden; young plants duly arrived, somewhat crumpled in the post.

One of them is a brightly-striped variety of miscanthus, a family of tall, rhizomatous (a plant with a horizontal, usually underground stem) grasses from Asia.

Now I discover that something very like it could be grown in waving savannahs as a raw material for a biofuel.

This is a hybrid of miscanthus and gigantea developed in Japan, sometimes miscalled "elephant grass" and reaching some 3.5 metres tall. In recent years, at least 10 European countries have been growing it experimentally, including a plot at Teagasc's Oak Park - a research station in Co Carlow.

Harvested in late winter or spring its dry stems yield some eight to 15 tonnes per hectare - fuel for power stations or feedstock for liquid ethanol.