The evidence mounted last week that man-made gases are causing deterioration of the earth's atmosphere.

It has become widely known that man-made gases, mostly oxides, rise into the stratosphere and create a blanket similar to the plastic or glass bubble that surrounds a greenhouse.

For their part, the Europeans accept the overwhelming scientific consensus that man-made gases are heavily responsible for the warming of Earth's atmosphere.

The crucial point is what to do about rising emissions of carbon dioxide, the principal man-made atmospheric gas among several that trap heat like the glass panes of a greenhouse.

An authoritative report has concluded that man-made gases contributed substantially to the rise in temperature over the last 50 years.

These man-made gases are present in the atmosphere only in tiny amounts, but because they accelerate the breakdown of ozone, they increase the hazard of excess ultraviolet radiation.

But the summary of the latest report asserts more confidently that man-made gases have "contributed substantially to the observed warming over the last 50 years."

The production of harmful man-made gases tipped the balance against ozone.

Both regard global warming caused by man-made gases that retain heat in the atmosphere as a significant threat to the environment and would call a meeting of world leaders to address it.

Fluorinated gases (F-gases) are man-made gases that can stay in the atmosphere for centuries and contribute to a global greenhouse effect.