Earth as a System: Energy, Matter, and Life

Warmer Arabian Sea water can increase evaporation and moisture, changing monsoon rainfall. Some places may get heavier rain while others may receive less.

Forest loss can increase erosion and runoff and can change local rainfall, affecting the river.

Faster melting can raise sea level and increase flood risk for low-lying coastal cities.

Some plankton use CO₂, but excess CO₂ acidifies seawater and can harm plankton and shell-forming organisms.

Examples: soil (geosphere), lake (hydrosphere), snow (cryosphere), air (atmosphere), sheep (biosphere). Snow melts and flows into the lake; less snow can lower lake water and reduce grass.

A change in one sphere spreads to others: less snow can mean less lake water, drier soil, and less water for plants and animals.

E = 1,000 W/m² × 1 m² × 3,600 s = 3.6 × 10⁶ J.

Estimate energy demand and panel output per square metre, then divide demand by output and include practical losses and spacing.

Fresh snow: 0.80–0.90; sea ice: 0.50–0.70; dark soil: 0.10–0.20; ocean: about 0.06. Higher albedo means more sunlight is reflected.

Increasing greenhouse-gas concentration generally raises surface temperature because more outgoing heat is absorbed.

A cool breeze can reduce heat stress and slow drying, helping crops and soil retain moisture.

Warm currents transfer heat toward the poles and can make nearby coastal climates milder.

Warming can reduce the ocean’s ability to store CO₂. Changes in acidity and temperature can harm corals, plankton, and other marine organisms.

Life would lose essential supplies: plants need recycled nitrogen, land organisms need water, and many organisms need oxygen.

Fossil fuels, deforestation, farming, and waste add greenhouse gases. Saving energy, using lower-emission transport, and reducing waste can help.

Option 2: nutrient cycles recycle matter between living and non-living parts.

Option 3: greenhouse gases trap some outgoing heat.

Climate change can intensify rain, drought, floods, and glacier melt.

High albedo reflects sunlight and cools; low albedo absorbs and warms.

Day: valley breeze uphill. Night: mountain breeze downhill.

Most weather occurs in the troposphere.

Bacteria fix nitrogen; plants and animals use it; decomposers and bacteria return it.

Deforestation releases carbon, erodes soil, disrupts rainfall, and removes habitats.

Air CO₂ → plants → food chain → respiration or decay → air CO₂.

Extra CO₂ traps heat and drives climate change.

Earth loses heat mainly as infrared radiation.

A flat Earth would have a different pattern of solar heating.

Warming melts ice, changes water, and shifts habitats.

The atmosphere supplies gases, blocks harmful UV, and retains heat.

Earth’s spheres interact; for example, rain enters soil and supports plants.

Both planets would have winds from equator-to-pole heating differences. The ocean planet would lack land-sea contrasts; the land planet would heat and cool faster and have no ocean currents.

Plant food gets carbon from air CO₂ through photosynthesis. Nitrogen enters soil through bacteria or fertiliser and then plants. Farming, transport, cooking, and waste can add emissions.

Use comparable five-year records for the same place and season, calculate averages and heavy-rain days, and state the trend supported by the data.

Compare records for rainfall, sea temperature, and land use. These factors can influence rainfall and runoff, but a trend alone does not prove cause.

Satellites and sensors can track Earth’s changes over time. Models use these data to find patterns and test climate predictions.