When global warming finally came, it stuck with a vengeance(异乎寻常地). In some regions,
temperatures rose several degrees in less than a century. Sea levels shot up nearly 400 feet, flooding
coastal settlements and forcing people to migrate inland. Deserts spread throughout the world as
vegetation shifted drastically in North America, Europe and Asia. After driving many of the animals
around them to near extinction, people were forced to abandon their old way of life for a radically
new survival strategy that resulted in widespread starvation and disease. The adaptation was farming:
the global-warming crisis that gave rise to it happened more than l0,000 years ago.
As environmentalists convene in Rio de Janeiro this week to ponder the global climate of the
future, earth scientists are in the midst of a revolution in understanding how climate has changed in
the past—and how those changes have transformed human existence. Researchers have begun to
piece together an illuminating picture of the powerful geological and astronomical forces that have
combined to change the planet’s environment from hot to cold, wet to dry and back again over a
time period stretching back hundreds of millions of years.
Most important, scientists are beginning to realize that the climatic changes have had a major
impact on the evolution of the human species. New research now suggests that climate shifts have
played a key role in nearly every significant turning point in human evolution: from the dawn of
primates(灵长类动物) some 65 million years ago to human ancestors rising up to walk on two legs,
from the huge expansion of the human brain to the rise of agriculture. Indeed, the human history has
not been merely touched by global climate change, some scientists argue, it has in some instances
been driven by it.
The new research has profound implications for the environmental summit in Rio. Among other
things, the findings demonstrate that dramatic climate change is nothing new for planet Earth. The
benign(宜人的) global environment that has existed over the past 10,000 years—during which
agriculture, writing, cities and most other features of civilization appeared—is a mere bright spot in a
much larger pattern of widely varying climate over the ages. In fact, the pattern of climate change in
the past reveals that Earth’s climate will almost certainly go through dramatic changes in the future—
even without the influence of human activity.
Passage Two
Questions 26 to 30 are based on the following passage.
No woman can be too rich or too thin. This saying often attributed to the late Duchess(公爵夫人
) of Windsor embodies much of the odd spirit of our times. Being thin is deemed as such a virtue.
The problem with such a view is that some people actually attempt to live by it. I myself have
fantasies of slipping into narrow designer clothes. Consequently, I have been on a diet for the better
—or worse—part of my life. Being rich wouldn’t be bad either, but that won’t happen unless an |
