We do not fully understand how these components influence each other and form the Earth's climate. However, we do know that these components will interact to produce future changes in climate in a similar way to how they have interacted to change the climate in the past. By understanding how these components of the climate system interacted to change the climate in the past, and how humans are influencing the climate system now, we can better determine what components of the climate system will be responsible for future changes in climate We must improve our understanding of the interactions of the components of the climate system in the past to confidently predict the future. In a nutshell, to predict the future, we need to understand the past. There are many ways to determine what the climate of the earth was in the past.
Historical records extend back at most a few thousand years.
Trees and ocean corals can record some aspects of climate, such as temperature, in the patterns of annual growth rings they produce. Deposits of wind-blown dust contain information about moisture and wind conditions. Nesting material from desert rodents can be used to estimate moisture and temperature conditions. Sediment deposits in lakes and oceans are used extensively to determine a wide variety of climate parameters on times scales that extend back millions of years. Glaciers and ice sheets are especially valuable because they record a great variety of climate records.