Uplift in science refers to the rising of portions of the Earths surface, while sinking of land refers to the downward shift of portions of Earths surface. Both uplift and sinking can be due to plate tectonic movements, including mountain building, or the gravitational adjustment of the Earths crust after material has been removed (resulting in uplift) or added (resulting in sinking) such as ice or sediment. The sinking of land can also result from human activities, such as ground water removal or mining, as well as from the melting of permafrost. Both the uplift and sinking of land can be associated with earthquakes.

Uplift of land affects the Earth system in a variety of ways, including over millions of years sustained uplift due to tectonic processes can lead to mountain building, such as the Himalayas. Sinking of land affects the Earth system in a variety of ways, including causing changes in relative sea level rise, which can flood urban areas and impact freshwater and soil quality, and in turn agricultural activities.

Uplift is also a key concept in the rock cycle, as it allows us to see rocks that were once deeply buried beneath the surface. If rocks did not get uplifted to form hills and mountains, then the processes of weathering and erosion would long ago have reduced much of the worlds land-masses to low-lying, flat plains.

In summary, uplift in science refers to the rising of portions of the Earths surface, and it can be due to plate tectonic movements, gravitational adjustment of the Earths crust, or human activities. It affects the Earth system in various ways, including mountain building and changes in relative sea level rise. Uplift is also a key concept in the rock cycle.