What type of soil particle has the smallest size?
Clay (<0.002 mm).
What is the main human activity that increases CO2 levels?
Combustion of fossil fuels.
What percentage of Earth's water is stored in the oceans?
96%.
What is the main use of rare earth metals?
Electronic components.
Which cycle involves processes like photosynthesis and respiration?
The carbon cycle.
What is the Universal Soil Loss Equation (USLE) used for?
Estimating soil erosion rates.
What phenomenon is caused by weakened or reversed trade winds in the Pacific Ocean?
El Niño.
What is the main cause of reduced downstream river flow due to water abstraction?
Excessive water extraction for human use.
What is "cut-off ore grade" (COOG)?
The minimum ore purity that can be economically exploited.
What human activity increases nitrous oxide emissions?
Use of nitrogen-based fertilisers.
How does contour ploughing reduce soil erosion?
It reduces runoff velocity and increases water infiltration.
How does melting land ice contribute to sea level rise?
Water from melting ice flows into the sea, increasing its volume.
What is one consequence of thermohaline circulation disruption in the North Atlantic?
Cooling of North-West Europe.
What geological process forms hydrothermal mineral deposits?
Hot, mineral-rich solutions crystallize in fissures due to changes in pressure and temperature.
What is eutrophication, and what causes it?
It is the nutrient enrichment of water bodies, often caused by nitrate and phosphate runoff.
What is the primary environmental impact of soil compaction?
Reduced infiltration, leading to increased runoff and erosion.
What is the role of the North Atlantic Conveyor in regulating the climate of North-West Europe?
It transports warm water from the tropics to the region, preventing colder temperatures.
Explain how afforestation affects the hydrological cycle.
It increases interception, reduces runoff, and enhances transpiration, promoting precipitation.
How does bioleaching work in mineral extraction?
Bacteria oxidise sulfur to sulfuric acid, leaching metals from ores.
How does mycorrhizal fungi improve phosphate uptake in plants?
They increase root surface area, enhancing absorption.
Describe a method to reduce soil compaction in agriculture.
Adding organic matter to support soil biota like earthworms.
Describe one positive and one negative feedback mechanism associated with climate change.
Melting permafrost releases methane, increasing warming. Negative: Increased low-level cloud cover reflects sunlight, reducing warming.
Name one method for increasing the sustainability of water resource management.
Using greywater for non-potable purposes like irrigation.
What is Lasky’s principle?
As ore purity decreases linearly, the amount of material increases logarithmically.
Describe one method to manage the phosphorus cycle sustainably.
Recycling phosphorus from sewage sludge for use as fertilizer.