What are the key theories and techniques of geomorphology from the 20th century onwards? ‘Studying landscapes today ’ looks at plate tectonics and Earth system science (ESS). ESS is the study of the whole system of the Earth, including global environmental changes between the land and the atmosphere, water, ice, biosphere, societies, technologies, and economies. ESS offers a holistic approach. Geomorphology is now more technology-based, with the use of differential GPS (DGPS) (the GPS is roving, often carried in a geomorphologist's backpack) providing accurate data about topology. Ground-based LIDAR (light detection and ranging) is very accurate for surveying detail. Other technologies include ground-penetrating radar (GPR), carbon dating, radiometric dating, and cosmogenic dating.