The Kyoto Protocol, an icon of the global environmental movement, is finally taking legal effect after years of controversy since it was agreed in 1997.

The United Nations-sponsored treaty is meant to slow the rise of global temperature. Its goal is to reduce emissions of heat-trapping gases such as carbon dioxide from road and air transport, industries and power stations by 5 per cent below 1990 levels by 2012.

The protocol's entry into force is a huge political victory for the dream of limiting global emissions.

Celebrations have been arranged by environmentalists who believe dangerous changes to the Earth's climate will take place before long unless action is taken now.

Prayers for the treaty's success might be more in order, however, since most countries bound by it are not on track to curbing emissions by the required amount, New Zealand foremost among them.

The pact requires New Zealand to reduce greenhouse gas emissions by 2012 to what they were in 1990. But the opposite is happening.

Ministry of Economic Development statistics show that our oil consumption increased by 7 per cent in the year to March 2004. Coal production, including exports, rose by 25 per cent.

Total consumer energy use rose 5.4 per cent to close to five million gigajoules in 2002, the highest level since 1974.

It is all part of a worsening trend. A report released by the ministry reveals that New Zealand had the second-highest percentage increase of carbon dioxide emissions amongst the 23 OECD countries between 1990 to 2000.

The report shows that greenhouse gas emissions from the energy sector grew by 33 per cent between 1990 and 2002. And the trend is upwards. Emissions grew by 2.7 per cent from 2001 to 2002, up from the average annual growth of 2.4 per cent since 1990.

The Kyoto Protocol allows countries to meet their carbon emission targets by planting forests to soak up carbon instead of making emission cuts. The Government expects that short-term forest sinks of carbon will cover the inevitable increase in our emissions of greenhouse gases, leaving a surplus of carbon credits to sell on the international market.

The Government's hope is that New Zealand can manage to claim credit for the carbon dioxide taken out of the atmosphere by trees. This is permissible provided trees used for credit were planted since 1990 on land that was not previously forested.

New Zealand treaty negotiators pushed for this stipulation to be written into the Kyoto Protocol at a time when new area planted in trees in this country was at its peak, at about 100,000ha in 1994.

Sadly, the rate at which land was switched to commercial forestry has declined rapidly ever since, to an estimated 15,000ha in 2003. This is half the annual rate of 30,000ha that Government officials assumed when New Zealand ratified Kyoto.

The country is unlikely to rapidly reverse this trend. Rural land prices continue to rise, increasing the cost of forestry investment beyond what investors find acceptable. Returns on sheep and beef farming continue to improve past the point at which land in pasture is more attractive than land in trees.

The result: returns to tree growers will decline along with investment in this area.

For all these reasons, opponents of Kyoto argue that New Zealand is fighting a losing battle. And the outcome could be costly.

Of the 141 nations that are signatories to the UN accord on emissions, only 30 are legally bound to the Kyoto treaty. Most of the world, including big carbon dioxide-producing countries such as Brazil, China and India, do not have emission reduction targets, and Australia and the United States refuse to take part.

The result is that 89 per cent of the world's population live in countries that are not committed to Kyoto. These same countries emit 75 per cent of the world's carbon dioxide.

Realising the goal of capping global emissions is still a long way off.

* Chris de Freitas is an associate professor in geography and environmental science at Auckland University.