Liu said that studies showed that Taiwan ranks fourth in the world in per capita carbon dioxide emissions in the past ten years behind United States, Australia, and Canada.

Liu made the statement as part of a special report at the Legislature yesterday.

Liu cited a United Nations report which said that the world's average temperature will rise by 1.1 to 6.4 degrees Celsius by the end of the 21st century, higher than the 0.6 degrees rise in the twentieth century.

Research has shown that man-made greenhouse gases account for 90 percent of the factors behind the worldwide rise in temperature, Liu said.

Taiwan's temperature over the past hundred years has risen twice the rate of the worldwide average, Liu said.

Also, after 1970, the relative humidity in Taiwan has dropped, with days of 90 percent relative humidity decreasing by one half.

Due to the drop in relative humidity, fog in big cities such as Taipei, Taichung, and Kaohsiung has seen a sharp decrease.

Scenic area Sun Moon Lake in Nantou County saw its number of foggy days decrease from 200 days to today's 100 days, said Liu.

Liu said that Taiwan has also seen a decreasing amount of light drizzle and a thirty percent increase in heavy rain since 1970.

United Nations has predicted that temperatures around the world will rise in the 21st century along with the sea level, which will bring an increase in the number and strength of thunderstorms and typhoons to Taiwan.