AP BIOLOGY

Detailed explanation-1: -Scientists study Earth’s climate and how it changes in a variety of different ways, using satellite, instrumental, historical, and environmental records. One challenge of using satellite and instrumental data is that their lifespans have been rather short when compared to Earth’s life.

Detailed explanation-2: -Freshwater runoff from glaciers also influences ocean ecosystems. Glaciers are important as an indicator of climate change because physical changes in glaciers-whether they are growing or shrinking, advancing or receding-provide visible evidence of changes in temperature and precipitation.

Detailed explanation-3: -They collect ice cores in many locations around Earth to study regional climate variability and compare and differentiate that variability from global climate signals. The samples they collect from the ice, called ice cores, hold a record of what our planet was like hundreds of thousands of years ago.

Detailed explanation-4: -Ice cores provide direct information about how greenhouse gas concentrations have changed in the past, and they also provide direct evidence that the climate can change abruptly under some circumstances.