Chapter at a glance
How energy from the Sun and the cycling of matter keep Earth’s systems going: uneven heating, winds and ocean currents, biogeochemical cycles, and human impact.
What this chapter covers
- 13.1 Uneven Heating of the Earth
- 13.2 Uneven Heating Causes Wind and Ocean Currents
- 13.3 Biogeochemical Cycles
- 13.4 Human Impact on Earth’s Processes
Key points
- Solar radiation is Earth’s main energy source; most weather happens in the troposphere.
- Earth’s shape, latitude and axial tilt cause uneven heating, which drives winds and ocean currents.
- Water, carbon, nitrogen and oxygen cycle between the atmosphere, oceans, land and living things.
Read the NCERT chapter
Read this chapter in the official NCERT textbook Exploration (2026-27 edition) for free on ncert.nic.in.
Source: NCERT, Exploration, Grade 9 (2026-27). NCERT chapter PDF. Spotted a mistake? Email edura.class9.yt@gmail.com. Last updated 11 October 2026.