Unit 4: Earth hazards and climate change

A focused answer to the WACE Year 12 Earth and Environmental Science dot point on human greenhouse emissions and the evidence for anthropogenic warming. Covers fossil fuels, land clearing and agriculture, rising carbon dioxide and methane, isotopic fingerprints, instrumental and proxy evidence, and how natural causes are ruled out.

A focused answer to the WACE Year 12 Earth and Environmental Science dot point on climate feedbacks. Covers positive feedbacks such as ice-albedo, water vapour and permafrost methane, negative feedbacks, the distinction between forcing and feedback, and tipping points, with worked reasoning.

A focused answer to the WACE Year 12 Earth and Environmental Science dot point on climate change impacts and responses. Covers impacts across the four spheres, the distinction between mitigation and adaptation, key strategies, and evaluation, with WA examples such as a drying southwest and coral bleaching.

A focused answer to the WACE Year 12 Earth and Environmental Science dot point on ice-core and isotope proxies. Covers trapped air bubbles as a record of past greenhouse gases, oxygen isotope ratios as a temperature and ice-volume proxy, dating by annual layers, and how the records link carbon dioxide to temperature.

A focused answer to the WACE Year 12 Earth and Environmental Science dot point on biological and sedimentary climate proxies. Covers tree rings, pollen records of past vegetation, coral growth bands, and ocean and lake sediments, what each reveals, and their timescales and limitations, with Australian context.

A focused answer to the WACE Year 12 Earth and Environmental Science dot point on earthquakes. Covers elastic rebound, focus and epicentre, P, S and surface waves, the moment magnitude scale, the Mercalli intensity scale, and the factors that affect shaking, with Australian context.

A focused answer to the WACE Year 12 Earth and Environmental Science dot point on human-caused climate change. Covers the greenhouse effect, human emissions, evidence, impacts on Earth systems, and mitigation and adaptation, with Australian examples.

A focused answer to the WACE Year 12 Earth and Environmental Science dot point on the greenhouse effect. Covers incoming shortwave and outgoing longwave radiation, how greenhouse gases absorb and re-emit infrared, Earth's energy balance, and why the natural greenhouse effect makes Earth habitable.

A focused answer to the WACE Year 12 Earth and Environmental Science dot point on hazard prediction and mitigation. Covers volcano monitoring, the limits of earthquake prediction, tsunami warning systems, and structural and planning mitigation, with evaluation and Australian and regional examples.

A focused answer to the WACE Year 12 Earth and Environmental Science dot point on hazard versus risk. Covers the definitions of hazard, risk, exposure and vulnerability, how risk combines them, and why the same hazard causes different disasters in different places, with comparative examples.

A focused answer to the WACE Year 12 Earth and Environmental Science dot point on Milankovitch cycles. Covers eccentricity, axial tilt and precession, how they change the amount and distribution of solar energy, how feedbacks amplify them into glacial cycles, and how the present warming differs.

A focused answer to the WACE Year 12 Earth and Environmental Science dot point on natural climate change. Covers Milankovitch cycles, solar and volcanic forcing, feedbacks, and proxy records from ice cores, sediments and tree rings, with examples.

A focused answer to the WACE Year 12 Earth and Environmental Science dot point on plate tectonics. Covers the driving mechanism, divergent, convergent and transform boundaries, the processes at each, and how they explain the distribution of volcanoes and earthquakes, including why most of Australia is tectonically quiet.

A focused answer to the WACE Year 12 Earth and Environmental Science dot point on solar, volcanic and oceanic climate forcings. Covers solar output variation, volcanic aerosol cooling, ocean circulation and El Nino and La Nina, distinguishing short-term variability from long-term change, with Australian context.

A focused answer to the WACE Year 12 Earth and Environmental Science dot point on tsunami physics. Covers generation by sea-floor displacement, deep-ocean speed and small height, shoaling and amplification near shore, drawback, and why the WA coast is exposed, with the 2004 Indian Ocean example.

A focused answer to the WACE Year 12 Earth and Environmental Science dot point on tsunamis and hazard management. Covers tsunami formation, warning systems, prediction, risk, vulnerability and mitigation strategies, with regional examples.

A focused answer to the WACE Year 12 Earth and Environmental Science dot point on geological hazards. Covers plate boundaries, why volcanic eruptions and earthquakes occur, magnitude and intensity, and the Ring of Fire, with regional examples.

A focused answer to the WACE Year 12 Earth and Environmental Science dot point on volcanic eruption style. Covers magma silica, viscosity and gas content, shield versus composite volcanoes, effusive versus explosive eruptions, volcanic hazards and the Volcanic Explosivity Index, with regional examples.