Climate Literacy Essential Principle 2 *2a. Earth's climate is
influenced by interactions involving the Sun, ocean, atmosphere,
clouds, ice, land, and life. Climate varies by region as a
result of local differences in these interactions. *2b. Covering
70% of Earth's surface, the ocean exerts a major control on
climate by dominating Earth's energy and water cycles. It has
the capacity to absorb large amounts of solar energy. Heat and
water vapor are redistributed globally through density-driven
ocean currents and atmospheric circulation. Changes in ocean
circulation caused by tectonic movements or large influxes of
fresh water from melting polar ice can lead to significant and
even abrupt changes in climate, both locally and on global
scales. *2c. The amount of solar energy absorbed or radiated by
Earth is modulated by the atmosphere and depends on its
composition. Greenhouse gases—such as water vapor, carbon
dioxide, and methane—occur naturally in small amounts and absorb
and release heat energy more efficien