On the face of it, the target for greenhouse gas reductions agreed in Kyoto this week seem paltry, even pathetic. But the really important thing about the world's first treaty on climate change is that it moves the whole process decisively in the right direction.

Extracting the required concessions from some of the participating countries, notably the United States and Japan, was not unlike a long-drawn-out dental appointment, with a lot of pain and even some blood on the floor, though the European Union proved to be quite a good dentist.

They had come to Kyoto offering little (Japan) or nothing (the US). But by the time they left after the final round of all-night negotiations both countries had agreed to the Protocol and pledged to cut the greenhouse gas emissions.

The EU had won considerable kudos by offering to reduce its overall emissions by 15 per cent on 1990 levels by the year 2010. But it was clear from the outset that its major industrial competitors were never going to come close to matching this ambitious target. A diplomatic compromise was inevitable. In the end, the figures agreed in their tripartite talks worked out at 8 per cent for the EU, 7 per cent for the US and 6 per cent for Japan, all to be achieved over a four-year period from 2008 to 2012. The industrialised world as a whole also signed up to an overall cut of 5.2 per cent.

The US is livid that one of its key conditions, "meaningful participation" by key developing countries, had to be dropped in the face of implacable opposition from China and India. Indeed, only the fear of being blamed for a failure in Kyoto kept the Clinton administration on board.

The G77 Group, which represents 136 developing countries, insisted that the industrialised nations must be the first to take action on the issue, since it was their emissions of carbon dioxide and other greenhouse gases which had caused the problem of climate change in the first place. At stake was the issue of "global equity" as G77 sees it. Though emissions from China, India and other major developing countries are rising fast and will ultimately outstrip those from the industrialised world, they remain very low on a per-capita basis, by factors of up to 20 to one.

The US, with only 5 per cent of the world's population, is the biggest emitter of carbon dioxide, accounting for nearly 25 per cent of the global total. If it did not agree to make real cuts, there would be no chance whatsoever of persuading the developing world to sign up, even on a voluntary basis. President Clinton was kept under relentless pressure by the mis-named Global Climate Coalition (GCC), which primarily represents US oil, coal and motor manufacturing interests. It set out to ensure that the Kyoto summit would end in failure or, at least, in the realm of meaningless declarations.

The Exxon Oil Company, one of the GCC's leading members, was to the fore in pressing the US administration to insist that the developing countries were stitched into any deal in Kyoto. At the same time, it was calling on them to increase their own consumption of oil to promote economic growth. By far the most hysterical statement issued during the 10-day summit came from the GCC itself. It claimed that the agreement amounted to "unilateral economic disarmament" by the US that would throw three million Americans on to the dole queue and cost the economy $150 billion a year.

Such assertions are regarded as quite outlandish by environmental groups and by the European Union.

Of course, because the Kyoto summit decided on lower greenhouse gas reduction targets, the EU's famous "bubble" will have to be renegotiated. But the danger here is that its 15 member-states, including Ireland, would be allocated lower targets, thus undermining Europe's high moral ground. This would be a great mistake, not least because of the message it would send the key developing countries such as China. Mr John Prescott, Britain's Deputy Prime Minister, has already reaffirmed its intention of sticking by its original targets and there is no reason why Ireland can't do the same. There are all sorts of "win-win" measures which can be taken to reduce greenhouse gas emissions, such as serious energy conservation, investment in alternative energy sources, more fuel efficient vehicles and most of all the imposition of a "carbon tax' to shift the burden from PRSI.

Internationally, the primary task between now and the fourth Climate Change Summit in Beunos Aires next November will be to iron out the details of such US-inspired initiatives as "emissions trading" to ensure that these are not used to avoid action to curb greenhouse gases on the home front. As for those who discount the whole thesis of climate change, the meteorological data for Kyoto tell their own story. A century ago, the city had 100 days of frost every winter; now it has 15 and there are still roses in full bloom and bright red leaves on the Japanese maples in mid-December.

In November one of the world's leading insurance companies, Munich Re, warned that the potential losses from an extreme natural catastrophe affecting one of the planet's major cities or industrial centres might "bring about the collapse of the world's financial markets".

The most memorable speech at the Kyoto summit was delivered by Mr Kinza Clodumar, president of the Polynesian Republic of Nauru. Like other low-lying small island states, Nauru is threatened with extinction, and its President talked movingly about how his people were now "trapped" between an interior devastated by colonial phosphate mining and the prospect of "a terrifying flood of biblical proportions" due to rising sea levels. "The wilful destruction of entire countries and cultures with foreknowledge would represent an unspeakable crime against humanity," he declared. "No nation has the right to place its own misconstrued national interest before the physical and cultural survival of whole countries."

In this context, the Kyoto Protocol may be seen as a squalid formulation of the lowest common denominator. But at least it indicates that world leaders are at last prepared to face up to the powerful fossil-fuel lobby and start dealing with this truly overwhelming environmental issue.