How can scientists learn about climatic history?
What will be an ideal response?
Scientists can directly measure gases known to change climate. They also can use models such as coupled general circulation models. They can drill into Earth's ice caps and glaciers to extract cores of ice, which contain trapped air bubbles of the ancient atmosphere. Atmospheric gases, temperature trends, precipitation, and solar activity can be determined from these bubbles. Scientists also collect cones of sediments at lake bottoms, which contain pollen and other plant remnants that can indicate regional climate. Plant fossils of cones, tree stems, and bark indicate vegetational and climatological history of local areas. Charcoal indicates where forest fires may have occurred. Ice core analysis has given information about climate more than 800,000 years ago, while sediment, charcoal and other plant remains give data about more recent times. Finally, long-term research projects such as FACE are telling us how plants may respond to or mitigate elevated levels of CO2.
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What will be an ideal response?
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What will be an ideal response?
Looking at the number of nuclear power plants under construction in 2014,
A) the largest numbers have been in the United States, Canada, and France. B) China, the Russian Federation and India are in the lead. C) nuclear power is decreasing globally, with coal-fired plants increasing sharply. D) the IAEA predicts that the current trend will be reversed.