Before this July was half over, the sun was already so worked up that people in the Northern Hemisphere found it hard to take.

Spread open a world map and take a look at Europe. In early July Greece was hit by a heat wave, and more than 600 people were hospitalized with heat stroke. Doctors felt obliged to call off a strike and go back to work to treat them.

In Mainland China the situation was even worse. In Nanking, long known as the "blast furnace" of China, over eighty people died and more than 1,000 were hospitalized when the city suffered its third highest temperatures since 1906. And the temperature in Shanghai topped 100°Ｆ (38℃), a record held for half a century, for several days in a row.

In the United States farmers are suffering from the worst drought since the 1930's. Many countries that depend on imports of U.S. grain are in a quandary, and stock prices around the world have tumbled.

According to researchers' statistics, the first five months of this year were the world's hottest in the last hundred years. By June the whole Northern Hemisphere had come down with a fever. In early July an atmospheric science expert at NASA pointed out that unless a strong cold wave appears in the Southern Hemisphere, this year will go down as the hottest in history.

In fact, the heat wave has been going on for many years already. Records show that the world's weather has been getting hotter and hotter since 1970.

"Why is the weather getting hotter?" Chiang Shan-hsin, an associate professor of geography at National Taiwan University, repeats in reply to a reporter's question. He believes it helps to know that the world has been around for 4.1 to 5 billion years, during which time the weather has been constantly changing. Three ice ages have occurred during the last 600 million years, each separated by a warm interglacial period. "Mankind has arisen during the fourth interglacial period," he says.

When researchers say, "the weather is getting hotter now," they're only talking about the average temperature during the past thirty years or so and not in terms of geological time. But Chiang points out that "seeking an answer as to why the weather is getting warmer is something that meteorologists and climatologists are working all out on."

A drought occurred in the West of the United States during the 1930's similar to the one happening today. Not until fifty years later did scientists surmise that the high temperatures back then might have been caused by increases in the sun's radiation due to changes in sunspot activity. The sunspot theory is a controversial explanation of changes in the earth's climate.

Another theory attributes the changes to the effect of the E1 Nino current off the coast of Peru. Other scientists blame variations in the earth's rotation around the sun. "Trying to get the whole picture is like working on a jigsaw puzzle," Chiang says.

The latest explanation is the greenhouse effect. According to this theory, infrared solar radiation is prevented from dissipating into space by the atmosphere's ozone, water vapor, and carbon dioxide, resulting in a steady rise in temperatures. In the past the amount of carbon dioxide in the atmosphere remained at about the same level, but since the nineteenth century it has increased by forty percent, holding in more and more infrared radiation.

Why has the carbon dioxide level increased? Whenever you burn fuel, you give off carbon dioxide, and mankind's consumption of coal and petroleum has increased by twelve fold since the early nineteenth century. Another factor has been the decimation of the world's forests, which convert carbon dioxide into oxygen through photosynthesis.

Yet another manmade cause of the earth's heating up is said to be the destruction of the ozone layer caused by the release into the atmosphere of chlorofluorocarbon (CFC), which is used in refrigeration, aerosol cans, and the computer industry. Destruction of the ozone layer would let in harmful ultraviolet radiation, leading to increased cases of skin cancer, the death of plankton in the oceans, and crop failures.

Sunspots and the E1 Nino current may be beyond man's control, but "the green-house effect could become an example of the sins of the fathers visited upon their children unto the umpteenth generation," says an American scientist, who believes that we all must work together to solve the problem.

A first step has already been taken. The Montreal Treaty calls for a freeze on the production of CFC, which is produced mainly in the U.S., the Soviet Union, and Western Europe. Because CFC is such a convenient product, however, many countries have been unwilling to cooperate.

"If mankind is going to continue to be penny wise and pound foolish," says Feng P'eng-nien, an experienced television meteorologist, "then we're really headed down a one-way street and there's no going back."

What will our future be like? The answer is yet to know.

[Picture Caption]

Carbon dioxide and chlorofluorocarbons exacerbate the greenhouse effect. (illustration by Lilian Lee)

The twentieth century is the age of petrochemicals. They make life more convenient but also create lasting damage.

Drought continues to occur in many countries around the world, and water has become an even more precious resource. (photo by Arthur Cheng)

Outdoor workers think up ways to block the sunlight. The ozone layer, like this umbrella, prevents ultraviolet rays from harming life on earth.

Between tall buildings and traffic the weather is getting hotter and hotter.

The twentieth century is the age of petrochemicals. They make life more convenient but also create lasting damage.

Drought continues to occur in many countries around the world, and water has become an even more precious resource. （photo by Arthur Cheng）

Outdoor workers think up ways to block the sunlight. The ozone layer, like this umbrella, prevents ultraviolet rays from harming life on earth.

Between tall buildings and traffic the weather is getting hotter and hotter.