Explain the method scientists use to study how Earth’s atmosphere and climate have changed during the past million years.

Answer:

Scientists first collect ice cores from deep under the arctic and antarctic ice shelves. Next they measure the concentrations of gasses trapped in the ice to determine how long ago the ice was formed and what the composition of the atmosphere was like at the time. These ice cores are like little time capsules showing what Earth’s atmosphere and climate were like in the past.