[单项选择]

Scientists have long warned that some level of global warming is a done deal—due in large part to heat-trapping greenhouse gases humans already have pumped skyward. Now, however, researchers are fleshing out how much future warming and sea-level rise the world has triggered. The implicit message: "We can’t stop this, so how do we live with it" says Thomas Wigley, a climate researcher at NCAR.
One group, led by Gerald Meehl at NCAR, used two state-of-the-art climate models to explore what could happen if the world had held atmospheric concentrations of greenhouse gases steady since 2000. The results: Even if the world had slammed on the brakes five years ago, global average temperatures would rise by about 1 degree Fahrenheit by the end of the 21st century. Sea levels would rise by another 4 inches over 20th-century increases. Rising sea-levels would continue well beyond 2100, even without adding water from melting glaciers and ice sheets. The rise hi
A. unrelated.
B. similar.
C. complementary.
D. opposite.