Milankovitch cycles are long-term astronomical variations that alter the amount and distribution of solar energy received by Earth, acting as the primary driver of glacial-interglacial transitions over geological time.
Which of the following statements correctly defines the Milankovitch cycle known as obliquity and its characteristic periodicity?
The variation in the shape of Earth's orbit between near-circular and more elliptical pathways over a cycle of approximately 100,000 years, which alters the seasonal variation in distance between Earth and the Sun.
The variation in the angle of Earth's axial tilt relative to its orbital plane between 22.1∘22.1^\circ22.1∘ and 24.5∘24.5^\circ24.5∘ over a cycle of approximately 41,000 years, which directly dictates the intensity of seasonal temperature contrasts.
The wobbling motion of Earth's rotational axis in space over a cycle of approximately 23,000 years, which alters the timing of the seasons relative to when Earth is closest to or furthest from the Sun.
The periodic variation in solar radiation output driven by sunspot activity over a cycle of approximately 11 years, which influences short-term global climate anomalies rather than long-term orbital cycles.
23 exam-style questions on OCR A GCSE Geography Climate change over time. Each one has a worked solution and a mark scheme showing where the marks go.