Feature

Cooling The Greenhouse

The government has pledged to reduce New Zealand's carbon dioxide emissions by 20% by 2000. Are such reductions possible? Are they necessary?

By Cathryn Crane, NZSM

Announced goals of reducing this country's carbon dioxide (CO₂) emissions by 20% within eight years have been heavily criticised. Environmentalists would like to see a much greater reduction made; critics of the global warming scenario warn that such a reduction would be disastrous economically and is based on flawed science.

In 1988, the Toronto-based conference on The Changing Atmosphere called for a reduction in CO₂ emissions by "approximately 20% of 1988 levels by the year 2005". Despite further refinements of climate change data away from the globally catastrophic predictions of the late 1980s, there appears to have been no comparable revision in emission targets.

Over 130 governments are currently involved in developing an international climate convention which will set emission reduction targets. The convention is expected to be ready by the June meeting of the United Nations Conference on Environment and Development.

Government Response

In June 1990, the then Labour Government committed the country to reducing carbon dioxide emissions by 20% by 2005. A Ministry of Commerce paper on the potential for reductions concluded that such a reduction was technically feasible, but that it would be extremely difficult.

In the run-up to the election, the National Party undertook to make the reductions by 2000 -- the fastest, most drastic reductions amongst all the developed nations. Concerns have been expressed that this decision was made without the benefit of a practical strategy of achieving that goal and without due consideration of the economic costs.

"Only when Government has that analytical information will it be able to make decisions on how far and how fast it can move towards that target," says Secretary for the Environment, Roger Blakeley.

That information should become available soon in a report from the NZ Climate Change Programme outlining some of the ways in which New Zealand can respond to the challenge. Climate change and ways of dealing with it was one of the first topics to be identified as a National Science Strategy.

Cost-Effective Measures

Blakeley is looking for measures which are cost-effective and which provide a good range of benefits, regardless of whether global warming occurs or not. Like many commentators, in analysing the situation he compares the desire to take action now as akin to taking out insurance.

"In this case, the insurance policy would be to start doing things now that make economic sense in their own right, for example you don't need proof of the greenhouse effect for energy efficiency to be a good idea, because it has both environmental and economic benefits," says Blakeley.

The emissions goal represents a reduction of 2% per year, requiring a 5% improvement in this country's energy efficiency every year. Energy efficiency appears to be the main way of approaching this target, along with fuel substitution and a reduction in energy usage or the growth thereof.

Energy Efficiency

According to Blakeley, cost-effective, energy efficient techniques used in four areas -- domestic water heating, home heating, lighting and appliances -- would be enough to prevent the need for the planned future power stations of Waikato thermal, lower Clutha hydro, Queensbury hydro and Mokai geothermal.

"Improved energy efficiency will buy us time but, in the long run, we must be looking to renewable energy sources such as solar, wind and wave energy, hydro electricity and biogas," Blakeley says.

Kirsty Hamilton, Greenpeace's atmosphere and energy spokesperson, endorses that, citing overseas examples of energy efficiency programmes combined with alternative energy sources. Such strategies are practical and attainable, argues Hamilton. She points to a Dutch study which concluded that a 70% reduction of CO₂ would be possible by 2020 for less than 1% of GDP. The Dutch government has set a series of goals for promoting solar power, energy efficient appliances and changes in waste management.

Other strategies suggested to encourage the reduction in CO₂ levels include developing tradeable permits for emissions, establishing a series of incentives for reductions and legislating a set of strict emission standards.

One commonly suggested approach is to tax the carbon content of fossil fuels, a carbon tax. By raising the costs of using such fuels, it is hoped that users will find alternatives or reduce their usage. Gauging the economic ramifications of such a tax is extremely difficult, with most analysts seeing the primary result being a recession and loss of competitiveness.

Such a tax was introduced in Sweden but, to reduce the impact of increasing energy costs, the country's fuel prices were halved, effectively neutralising the strategy.

Fuel Switching

Fuel switching is another possible strategy, promoting natural gas or nuclear power. The latter is unlikely to be a popular choice for New Zealand's energy needs; the former has only 20 years or so of reserves available.

Energy and environmental coalition group Campaign Climate for Change is concerned about wastage of energy resources such as gas. They want to see the lifetime of the Maui gas field extended from 15 to 40 years through its efficient use, targeting the 30% used for petrol production at the Motonui synthetic fuels plant as wasteful of half the energy value.

Reforestation, with trees acting as a carbon sink, has been suggested as one potential measure to reduce nett emission quantities. A Forest Research Institute study suggests that converting 50,000 hectares of pasture to forestry would counteract current emissions. This magnitude of planting is possible -- 54,000 hectares was planted in 1985, the year of greatest planting. Doing this every year until 2050 would produce a forest of 4.5 million hectares, some four times the size of the current estate.

The FRI scientists concluded that "although industrial plantation forestry is clearly a beneficial tool for mitigation of the effects of fossil fuel combustion, its benefits should not be overstated, and are primarily due to a continuous programme of new planting on unforested sites. Afforestation, although useful in the short term, is no substitute for reduction in the consumption of fossil fuels".

CO₂ And Industry

Carbon dioxide reductions were targeted because CO₂ is a major greenhouse gas and its emissions are easy to measure and monitor.

New Zealand produces 1.5 times the world average of CO₂ per head each year, accounting for 0.1% of emissions globally. The gas represents a third of New Zealand's emissions of identified greenhouse gases.

Methane makes up 37% of such emissions, at five times the world average, and nitrous oxide some 15%. These gases come primarily from agricultural sources, such as manure, and landfill. Methane is a far greater source of infrared absorption than carbon dioxide. When oxidised in the atmosphere, it produces another greenhouse gas, water vapour.

Not surprisingly, some of the strongest critics of the CO₂ reduction measures come from the coal industry, which feels it has been singled out as a major producer of this greenhouse gas. Coal industry representatives argue that coal use produces only one-sixth of the annual CO₂ emissions.

"The target focuses on carbon dioxide, which is not New Zealand's main greenhouse gas, it allows no credit for reforestation to absorb carbon dioxide, and it is based on absolute emission levels, making no allowance for economic growth or population changes," argue Rob Whitney and Wayne Hennessy of the Coal Research Association.

Over half the CO₂ emissions produced each year come from the transportation sector, a by-product of hydrocarbon combustion. Campaign Climate for Change wants to see major changes in attitudes to transportation in New Zealand. They are keen to promote increased fuel efficiency, regular emission standards testing, better public transport and bulk freight systems, and increased use of CNG and LPG vehicles.

The natural gas industry has been promoting its energy source as a "clean" fuel, ignoring its high methane content. The assertions have prompted a certain degree of indignation in energy colleagues.

"The gas industry has attempted to take the moral high ground because its fuel is less carbonated than coal or oil," say Whitney and Hennessy. "The very high carbon dioxide content of Kapuni gas -- 41% by volume -- is conveniently ignored in this argument."

The main general area of agreement is that industry has to respond -- and has to be seen to respond -- to concerns over emissions.

"By demonstrating a willingness to act responsibly at home, New Zealand will increase its influence in the international arena," says Blakeley. "This will enable New Zealand to play a more effective role in the formation of a meaningful Framework Convention on Climate Change, and protect its domestic interest with respect to trade and economy."

How Warm Is Warm?

Debate on the reports released by the Intergovernmental Panel on Climate Change (IPCC) continues. Procedural problems meant that the IPCC report on response strategies was made without full input from the scientific assessment teams. Those critical of the panel's findings question whether the report, as released, represents a "consensus view".

Energy consultant Dr Vincent Gray maintains that the IPCC report crystallised all that is right and wrong with the present state of climate modelling.

"It gives an authoritative account of present-day knowledge of the Earth's climate, and factors which may affect it, but it is dominated by a desire to prove that the greenhouse theory works, in the teeth of the evidence," he says.

The Executive Summary has come in for specific criticism, in that it leaves out many of the uncertainties and qualifications noted in the main document. Of particular concern to global warming critics is the apparent failure of the computer models on which many of the assumptions are based.

"None of the models are able to predict past or present temperature changes," says Gray. "Most of them grossly exaggerate the observed increases and, although a few predict correctly the amount of the change since 1860, they do not explain why most of the change over that period took place before there was significant build-up of greenhouse gases."

He is particularly concerned that decisions are being based on worst-case models.

"The least that should be done is to abandon the high temperature predicting models and to concentrate our policies on those with the lowest predictions, which at least have some credibility," he says.

Gray points out that even the IPCC report mentions that natural climate variability could explain the last 130 years of temperature readings. Climate change proponents admit that there is a great deal of research necessary.

"There are still important scientific questions about climate change which require further investigation," says David Wratt of the NZ Meteorological Service, adding that these concerns were clearly expressed in the IPCC report.

However, it is likely that it will be some time before unequivocal evidence is available, if ever. In the face of the highly publicised potential dangers of global warming, politicians and administrators are naturally reluctant not to react.

"Uncertainty must never be an excuse for inaction in the face of unacceptable risk," says Roger Blakeley, Secretary for the Environment. "While scientists are still arguing about the probability of the enhanced greenhouse effect, there is little doubt that the overall consequences worldwide could be very serious."

Cathryn Crane is a freelance journalist with an interest in environmental issues.