Temperature rising.

No one denies the climate is changing and causing worldwide problems. But experts still are debating about how much of the change we've created ourselves and what to do about it

It's enough to make skiers groan and sun-lovers rejoice. But warmer weather has many scientists heating up with concern for what they see as serious trouble ahead.

While climatologists know Earth's atmosphere is warming because of natural causes, they're now admitting that human activities are to blame too. The earth's natural temperature changes lead to ice ages at one extreme and warm periods at the other. But, according to the United Nations Intergovernmental Panel on Climate Change (IPCC), the warming of the last century and especially of the last few years has been caused partly by the greenhouse gases we produce.

Carbon dioxide and other gases heating Earth hold infrared radiation in the atmosphere, resulting in a gradual warming of the planet. The gases also include methane, chlorofluorocarbons from air conditioners and refrigerators, and other emissions from automobiles, coal-burning industries, and garbage dumps.

Most of the scientific community believes that global warming is a severe problem. Predictions are that by early next century the level of greenhouse gases will be twice what they were before the industrial age began. One estimate is there will be a 2.5-degree increase in average temperatures by 2040.

Industrial nations produce half the world's greenhouse gases. The U. S. alone accounts for 20% of them. And, if the world doesn't start reducing them by 2000, the IPCC predicts: a partial melting of the polar icecaps that would flood coastal cities and some island nations; more and increasingly violent storms with unprecedented damage; disruptions to agriculture that would dramatically decrease crop production, increase drought, and force mass human migrations. The Panel thinks temperatures could rise by as much as 5 degrees Celsius by the end of the next century if current emission rates continue. In this century, the global temperature has risen by a little more than one half of one degree Celsius. Future changes would be more rapid than any in the past 10,000 years, the period in which civilization developed.

Even now, the comparatively small boost in temperature is changing our climate dramatically. According to Environment Canada, the summer of 1995 was the second warmest globally since worldwide recordkeeping started in 1866. Around the world, temperatures soared, forest fires blazed, and heavy rains pelted. All this points to more frequent and intense heatwaves in the summer, longer droughts and stronger floods and hurricanes. The second-worst year on record for forest fires in Canada was 1995. They consumed about 70,000 [km.sup.2] from Yukon to Quebec, an area about the size of New Brunswick, and resulted in firefighting costs of about $250 million.

Alberta experienced record rains in early June which led to "once-in-a-hundred-year floods," with damage in the province exceeding $50 million. During the same period, Atlantic Canada was hit with five early season tropical storms and hurricanes that brought monstrous waves to the east coast.

If the forecasts are correct -- and computer models have become more reliable -- many believe we're in for catastrophic climate changes. The United Nations scientific panel predicts spreading deserts, disappearing rivers and a half-metre rise in the global sea level.

Five island nations -- the Maldives, Tuvalu, Tokelau, the Marshall Islands, and Kiribati -- are expected to disappear entirely in the next century as the world's sea levels rise. That's based on the 1.5 millimetre annual rise observed for decades, but satellite measurements show the oceans have been rising twice as fast in the past two years.

Closer to home, some experts say, most beaches on the East Coast of the United States could be gone in 25 years. They are already disappearing at an average of .6 to. 9 metres a year. In Canada, higher sea levels would affect the urban waterfront in several Maritime communities, with the disappearance of several fish-plant wharves, railway lines, roads, and bridges.

All this because of a little warm weather? Uh-huh.

As the German newspaper Der Spiegel pointed out recently, average global temperatures have never fluctuated by more than one degree since the last ice age ended 10,000 years ago. But even that "minimal cooling may have pushed the Germanic peoples southward in 375 AD to destroy the Roman Empire. An average warming of just one half of one degree enabled the Vikings who settled Greenland to raise cattle and sail to America.

"The last time it was three degrees warmer than now was more than 100,000 years ago. Then, Central Europe had a climate like Africa's. And Just three degrees separate today from ... the last ice age. Then, half of Europe lay under ice, and the sea level was 120 metres lower than it is today. A bitter north wind nipped at the ears of the polar bears living atop the frozen Baltic."

The newspaper adds that future warming is expected to cause drought in southern Spain and Italy, parts of Greece, large areas of Africa and the Middle East, and the southern United States. In the North, it will be warmer and more humid. On what is now perma-frost in Siberia and Canada, grain may grow, and surfing may catch on in Iceland.

To halt global warming by 2050, IPCC says at least half of the world's energy must come from sources that don't produce greenhouse gases. The panel says that keeping the concentrations of carbon dioxide at one to two times present concentrations (350 to 750 parts per million) can be attained only by cutting human-induced emissions to well below 1990 levels.

According to a 1994 report from the Conference Board of Canada, a tax on the carbon content of fossil fuels such as gas, oil, and coal would be one of the best ways for Canada to stabilize emissions that contribute to global warming.

A carbon tax, which has been implemented by several European countries -- but has been vigorously opposed in Canada by Alberta -- would increase in proportion to a fuel's carbon content. So, coal would be taxed more than oil, and oil more than natural gas, for example.

The report says a carbon tax would promote the use of noncarbon energy sources instead of fossil fuels, encourage industry to invest in energy-efficient technologies and lower carbon dioxide emissions.

The Alberta government, some energy bureaucrats, and most industry groups want Ottawa to rely on voluntary measures. Others, including British Columbia, federal leaders, environment bureaucrats, and environmentalists think government regulations and policy changes are needed.

But the national program adopted by Ottawa and the provinces in February 1995 does rely on voluntary measures; it will leave the national output of greenhouse gases 13% higher in 2000 than 1990. At least two provinces, Ontario and British Columbia, plan to go much further than the national plan, with regulatory as well as voluntary measures.

According to a government report, B.C. has one of the most serious air-pollution problems in Canada. The problem, particularly in the Vancouver and lower Fraser Valley areas, is caused mainly by transportation emissions. And, the B.C. government plans to adopt the highest emissions standards in Canada in 1996.

As B.C. Environment Minister Moe Sihota pointed out, even if cutting emissions is costly, there is the moral argument. "At some point, someone has to say no, the environment matters. It matters more than the chase for the almighty dollar."

Still, there are those who prefer a wait-and-see approach. They point out that the scientific evidence does not wholly support the notion that efforts to curb greenhouse gases will have a major overall effect on global warming. Is it wise, they wonder, to pump money into programs when it's uncertain how large an impact human activities actually have on the big picture.

That being the case, some say it would be better to prepare for the changes by building sea walls, for example, and irrigating dry areas, not launching a global campaign against the burning of fossil fuels.

A study led by British and U.S. scientists said we have to look elsewhere for answers. Only reduced population growth, full trade liberalization and major changes in farm practices, said the study, could lessen the effects of global warming on the world food supply. It excluded the effect of deep cuts to emissions of greenhouse gases from industrialized countries, which it said would not substantially alter its findings. The 1992 study was commissioned by the U.S. Environmental Protection Agency and involved 50 scientists in 18 countries. Its aim was to look at the effects of rainfall, warmer temperatures, and rising sea levels on world food production and prices.

Its key finding was that global warming would cause a drop of between 1% and 7% in world cereal production by 2060, with the largest decrease in developing countries. Although a forecast rise of an average one to five degrees Celsius would favour agriculture in Northern Europe and the countries of the former Soviet Union, much of Asia and Africa would face drought. But changes in farming practices such as growing different crops could reduce the downturn in cereal production to about 5% in developing countries.

It all adds up to a very different world where some feel we should focus on adapting to our changing climate. Others say if we don't take some positive action in reducing our emissions too, we could face even worse disasters.

SUGGESTED ACTIVITIES:

1. At the Earth Summit in Rio de Janeiro in 1992, governments agreed to hold down their output of greenhouse gases. But few of the 166 nations that signed the Rio treaty have stuck to the goal of reducing carbon dioxide emissions to 1990 levels by the year 2000. Neither was the Berlin conference on climate change in 1995expected to produce binding agreements committing nations to cut emissions. Is it worthwhile organizing global gatherings if all they come up with is false promises and bickering? Research both the Rio Summit and the Berlin conference and discuss the pros and cons of such worldwide efforts.

2. Some astronomers have suggested that the planet Venus might be Earth's future. The suggestion has been made that several billion years ago Venus had an hospitable environment that could have supported life. Scientists speculate that carbon dioxide started to build up in a greenhouse effect that got out of control and raised the surface temperature to what it is today -- 460 degrees Celsius. Write a short story based on this idea.

FACT FILE

The world climate between March and October 1994 was the hottest since records began in the 1860s; 1995 was the second hottest summer on record.

FACT FILE

Wit a three-degree global warming, say public-health experts in the Netherlands, the world could see as many as 80 million new cases of malaria each year.