SINCE the 1997 international agreement to fight global warming, climate change has worsened and speeded up – beyond even the worst expectations of the 1997 talks in Kyoto, Japan.
As world leaders have spent a dozen years trying to figure out what to do next, new ship passages have opened through the once frozen summer sea ice of the Arctic. In Greenland and Antarctica, ice sheets have lost trillions of tons of ice. Mountain glaciers in Europe, South America, Asia and Africa are shrinking faster than before.
And it's not just the frozen parts of the world that have felt the heat in the dozen years leading up to next month's climate summit in Copenhagen: The world's oceans have risen by about 4cm. Droughts  and wildfires have become more frequent worldwide. Animals and plants are now in trouble because of the changing climate. These include the polar bears, butterflies, frogs and entire stands of North American pine forests. Temperatures over the past 12 years are 0.4 degrees warmer than in the dozen years leading up to 1997.
Even the gloomiest (令人沮丧的) climate models from the 1990s didn't forecast results this bad.
“The latest science is telling us we are in more trouble than we thought,'' said Janos Pasztor, climate adviser to UN Secretary General Ban Ki-moon.
And here's why: Since an agreement to reduce greenhouse gas pollution was signed in Kyoto, Japan, in December 1997, the level of carbon dioxide in the air has increased by 6.5 percent. From 1997 to 2008, world carbon dioxide emissions (排放) from the burning of fossil (化石) fuels have increased by 31 percent. US emissions of this greenhouse gas have risen by 3.7 percent. Emissions from China have more than doubled.
Some climate change can be caused by natural factors such as variations in solar radiation, volcanoes, land drift (位移) and ocean drift. However, most of scientific and public opinion has come to the conclusion that the climate is changing mainly because of the accumulation of greenhouse gases (especially CO2) in the atmosphere due to human activity.
From December 7 to 18, officials from across the world will meet in Copenhagen to seek a solution for this problem. If successful, the meeting will send a clear signal to business and industry, governments and citizens around the world. New commitments and plans will signal that the future belongs to a low-carbon economy and that tomorrow's winners will be those who invest (投资) in clean energy solutions.
66. We can learn from the passage that        
A. The 1997 climate summit was held in Copenhagen
B. Since 1997,the level of carbon dioxide in the air has decreased by 6.5%.
C. The Copenhagen summit is intended to announce new ship passages to the Arctic
D. More than the frozen parts of the world have felt the heat in the dozen years
67. The underlined word “commitments” is closest in meaning to ______.
A. tasks B. taxes C. responsibilities D. regulation
(D)68. We can conclude from the text that ______.
A. governments will do more to fight global warming
B. world leaders have paid enough attention to global warming
C. the climate agreement signed in Kyoto did nothing to stop global warming
D. human activity is the main cause of global warming
(A)69. It can be inferred that            .
A. many countries haven’t stuck to the agreement signed in 1997 .
B. China should undertake major responsibilities for greenhouse gases emission as the country with the largest population.
C. The officials from developed countries and climate advisers should be responsible for the worsening climate.
D. Because of greenhouse gases glaciers in Greenland and Antarctic are melting faster than those in Europe, South America, Asia and Africa.
70. The main purpose of this article is to ______.
A. report on the upcoming climate summit in Copenhagen
B. inform about the effects of climate change and analyze its cause
C. tell people not to worry about climate change
D. urge people to do something about worsening global climate