Explain the various tools for studying climate change.

Scientists and meteorologists have been using instruments to measure climate and weather for the past 140 years. However, millions of years ago historical evidence called proxy data, which includes coral reefs, tree rings, ice cores, etc., were used to tell about the climate. 

Coral reefs:

1. Coral reefs are very sensitive to changes in climate. 

2. Corals form skeletons by extracting calcium carbonate from the ocean waters. 

3. When the temperature changes, densities of calcium carbonate in the skeletons also change. 

4. Coral formed in the summer has a different density than coral formed in the winter.

5. This creates seasonal growth rings on the corals. 

6. Scientists can study these rings to determine the temperature of the water and the season in which the coral grew.

Tree rings: 

1. Variation in these rings is due to variation in the environmental conditions when they were formed. 

2. Thus, studying this variation leads to improved understanding of past environmental conditions.

Ice cores: 

1. These are samples of ice taken from the inner sides of the ice sheets. 

2. Throughput each year, layers of snow fall over the ice sheets in Greenland and Antarctica.

3. Each layer of snow is different. 

4. Summer snow differs from winter snow. 

5. Each layer gives scientists a lot of information about the climate each year.