How can scientists learn about Earth's climatic history?

Question

What will be an ideal response?

Answer 1

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. Soot indicates where forest fires may have occurred. Ice core analysis has given information about climate more than 800,000 years ago, while sediment, soot, and plant remains give data about more recent times.