ANOTHER LIFE/Michael Viney: The shades of green that have swept across the acre must come close to the 40 of the ballad: it's only when oak and willow burst into leaf beside each other that you see how yellow a green can be, or how blue. In just a couple of weeks, the unfolding volume of leaf has been utterly transforming, like a whole marina of bare-masted yachts hoisting up their sails.
My impression over the past few years that summer vegetation is growing ever lusher is now backed up by science. A satellite study of Earth's chlorophyll reflections found that Ireland, along with Britain and the rest of northern Europe, is 12 per cent greener than it was 20 years ago. It's not just new vegetation - the existing trees and bushes are producing more leaves.
It's climate change, of course, however much we've shivered just lately.
A painted lady butterfly that fluttered through our garden on April 4th was an outrider of early spring warmth, though how it knew in Morocco it was safe to migrate to Mayo I can't imagine.
Those extra leaves, however, have a lot to do with rising levels of carbon dioxide, the gas that is trapping the warmth. It boosts the processes by which plants grow, an effect that shows up most strongly in seedlings, so if your rows of cabbage and lettuce seem to be leaping out of the ground it is not just due reward for tender loving care.
We can expect much bigger plants, growing faster: perhaps an extra 30 per cent of biomass, if the food is there to support it.
The more leaves there are, the more carbon they soak up in photosynthesis and later lock away in withered litter, humus and the soil. This "sequestered" carbon, two or three times the amount in living plants, eventually goes back into the air as soil organisms oxidise the humus, thus completing the carbon cycle.
The ability of plants to take carbon out of the atmosphere has made tree-planting an instantly attractive option for bringing CO2 levels down.
But are ever-expanding plantations of Sitka spruce and Douglas fir the best way to do it? Critics of the conifer strategy, quick to find the flaws in its carbon balance-sheet (ploughing up and draining peat, for example, releases much of its carbon) urge the use of fast-growing willows, to be harvested in rotation for biomass fuel: the UK has just announced the first six power stations specifically for willow. In the longer term, too, hardwood broadleaf trees are better at locking up carbon.
But growing trees is still a minuscule contribution to cutting back on our greenhouse gas emissions.
Will the Green Party, with its energy taxes, make more headway on the doorstep? Can they make better home insulation sound sexy? We shall see.
In the meantime, with Kyoto commitments still unfulfilled, how convenient to be able to argue that Ireland's grasslands, all 3.1 million hectares of them, may sequester almost half the CO2 produced in the State! This is the fond hope of scientists in Teagasc and UCC, who have begun a five-year study of the grassland carbon flux for the Environmental protection Agency. Their first results have suggested that intensively-grazed grassland may lock up as much as 10 tonnes of CO2 per hectare per year. With a national production of the gas at about 64 million tonnes a year, the arithmetic seems rivetingly simple.
Some 20 million tonnes of the carbon dioxide emissions come from farming.
But that is by no means the sum of its greenhouse gas contribution. Those CO2-swallowing Irish grasslands are grazed by around 7 million cattle all of them belching and farting methane at a rate of some 55 kilos per head per year, and almost as many sheep of rather more modest, but significant, flatulence.
Methane concentrations in the world's atmosphere are rising rapidly by 30 to 40 million tonnes each year, and although the gas contributes only about one-fifth of the overall warming, it is one of the more potent and volatile parts of the greenhouse mix.
Most of the world's methane is generated naturally by organic fermentation in the wetlands and bogs of the northern hemisphere: the warming of frozen tundra may account for much of the rise.
More of it comes from the millions of hectares of rice paddies that produce the gas by bacterial action in the mud. And the same anaerobic fermentation is at work in the slurry tanks of Irish farms.
The domestic ruminants of the world - sheep, goats and buffalo, along with cattle - produce some 77 million tonnes of methane annually in their four-chambered stomachs, especially if their diets are on the rough, high-fibre side. Finding digestive supplements to reduce the gas but not the beef or milk is a continuing challenge for ruminant nutritionists and microbiologists.
Scottish researchers have claimed that adding the bacterium Brevibacillus parabrevis, like a morning fix of yogurt, could cut the methane burps and farts by half.
The worst situation for the greenhouse scenario, as envisaged in the Government's own scientific studies, would be an increase in the number of cattle and sheep, coupled to an increasing dependence on tillage crops rather than grass.
On one hand, the new climate should favour the fixing of nitrogen in pasture by extra growth of white clover - which is good news. But the temptation will be to grow maize for fodder, which would mean ploughing up permanent pasture and releasing its carbon into the air.