Earth and Space Science

Question 1

Biosphere

Answer 1

The zone that encompasses all living organisms on the planet.

Question 2

Atmosphere

Answer 2

The layers of gas that surround the planet.

Question 3

Lithosphere

Answer 3

The upper layer of the mantle and the crust and includes all geological features on the surface of the planet.

Question 4

Hydrosphere

Answer 4

Includes all forms of water present on the planet in solid, liquid or gaseous states.

Question 5

Carbon Cycle

Answer 5

The carbon cycle is the process by which carbon moves through Earth’s four spheres—atmosphere, biosphere, hydrosphere, and lithosphere. It’s a continuous loop that includes absorption by plants through photosynthesis, release by organisms through respiration, decomposition, fossilisation, and combustion. This cycle maintains the balance of carbon on Earth to support life and regulate the climate.
Photosynthesis, respiration, decomposition, fossilization, combustion, carbon sinks/resevoirs.

Question 6

Natural Greenhouse Effect

Answer 6

Natural process that maintains the temperature of the Earth.
Process:
1. Solar Radiation: The Sun emits solar radiation, which reaches Earth’s atmosphere.
2. Absorption: Earth’s surface absorbs about 70% of this solar energy, warming up.
3. Infrared Radiation: The warmed Earth re-emits energy as infrared radiation (heat).
4. Greenhouse Gases: Gases like CO₂, CH₄, H₂O, and N₂O in the atmosphere trap some of this infrared radiation.
5. Re-radiation: The trapped heat is re-radiated back towards Earth’s surface, keeping it warm.
Importance:
~ Maintains Average Temperature: Without this effect, Earth’s average temperature would be around -18°C (0°F), instead of the current 15°C (59°F).
~ Supports Life: Regulates a stable climate and supports the water cycle, making Earth habitable.
Major greenhouse gases (GHG): CO2, H2O, methane, nitrous oxides

Question 7

Carbon Resevoirs/Sinks

Answer 7

A feature of the environment that absorbs and/or stores carbon therefore keeping it out of the stmosphere. Examples: limestone, forests, oceans, and fossil fuels.

Question 8

Climate Cycles

Answer 8

Glacial periods (ice ages):
Are periods of time where global temperatures drop significantly enough so that large glaciers appear across approximately 30% of the Earth’s surface. These periods are significant increases in land ice as well as sea ice. Within the last half a million years, glacial periods have been estimated to last around 70-90,000 years.
Inter-glacial periods:
Are periods of time where global temperatures increase where glaciers retreat and melt into the oceans causing sea level rises across the Earth. These periods are estimated to last around 10,000 years only. The current inter-glacial period (called the Holocene) is estimated to have lasted closer to 11,000 years and this may be attributed to human influences on climate change. Some scientists believe the Holocene may last as long as 150,000 years.

Question 9

Thermohaline Circulation for Deep Currents:

Answer 9

~ Ocean current system is driven by temperature and salinity differences, crucial for distributing heat and nutrients and regulating Earth’s climate.
~ Thermo = temperature-related
~ Haline = salinity and density related
~ Thermohaline = mixing of current controlled by temperature and density
~ As water sinks, some water needs to rise to replace it.
~ Sinking water is cold and dense, rising water is warm and less dense
~ As the water rises, it brings nutrients from the ocean floor
~ As water sinks, dissolved oxygen heads to the sea floor.

Question 10

Deep Currents

Answer 10

~ As fresh water freezes, ice forms from freshwater
~ Salt is left behind in this cold water, increasing density of the sea water
~ This liquid water sinks to the sea floor
As it sinks, it takes the place of slightly warmer water and this water moves slighly. (a few cms a year)

Question 11

Surface Currents

Answer 11

~ Driven by trade winds and the Coriols Effect
~ Surface waters push underlying layers of water in the same direction
~ As the water moves it begins to rotate in Ocean basins
~ These rotations are called ‘gyres’
~ Gyres spin clockwise in the Northern hemisphere and counter-clockwise in the Southern hemisphere
~ Surface currents are responsible for taking heat from equatorial regions to polar regions

Question 12

Enhanced Greenhouse Effect

Answer 12

~ Human influences have led to an increase of greenhouse gas concentrations in the atmosphere
~ This enhanced effect essantially traps more of the solar radiation within the atmosphere while letting out less
~ This increases global temperature around the globe, impacting weather systems
~ The most recognised human influence is the burning of fossil fuels that release carbon back into the atmosphere

Question 13

Anthropogenic Gases (Enhanced Greenhouse Effect)

Answer 13

Anthropogenic: Originating in human activities.
~ The word ‘anthropogenic’ refers to gases that are released into the atmosphere by human interactions
~ This increase of these anthropogenic gases is how the greenhouse effect has been enhanced by humans
~ Humans undertake a number of different activities that release these gases

Question 14

Coal (Enhanced Greenhouse Effect)

Answer 14

~ Coal is a natural mineral that is formed uner the surface of the Earth from ancient vegetation and is a long complex hydrocarbon
~ Humans extract this coal and use it to power energy grid across the Earth via burning
~ The aount of energy (and carbon) that humans release from coal is determined by the type of coal that has been extracted from underground
~ The four types of coal from lowest energy and least carbon content to highest are: Peat, Lignite, Bituminous and finally Anthracite
~ Humans use Bituminous coal to power most of our coal-fired power stations
~ The medium-grade coal has the second-highest level of coal and when burned, relseases carbon dioxide
~ In many countries there is a shit away from coal as a power source due to the large volume of carbon prouced per volume

Question 15

Crude Oil (Enhanced Greenhouse Effect)

Answer 15

~ Crude oil, much like coal is made of carbon from ancient fossilised organisms such as animals and algae
~ It also ahs a long hydrocarbon structure but smaller and less complex than that of coal
~ This structure has more hydrogen-carbon bonds and less carbon-carbon bonds meaning per unit of volume it releases less atmospheric carbon
~ Humans refine and combust oil for a number of industrial and commercial processes which releases the carbon stored inside it
~ Oil is extracted from resevoirs on land or under the surface of oceans and is then refined into a range of petroleum products such including diesel, lubricating oils, and petrochemical feedstocks for making urbbers and plastics
~ Each of these products, when destroyed or combusted, release carbon back into the atmosphere

Question 16

Natural Gas (Enhanced Greenhouse Effect)

Answer 16

~ Natural gas is the third largest fossil fuel used by humans and like coal and crude oil, also contain a large amount of carbon in the form of a short hydrocarbon, mostly methane (CH4)
~ As with crude oil, it forms from remains of microorganisms that have been subjected to heat and pressure
~ These deposits of methane-rich gas tend to appear near deposits of oil
~ Although mostly methane, other short-chain hydrocarbons such as ethane and butane can be present in natural gas
~ Humans use natural gas for heating, electrical generation, transportation and cooking
~ Natural gas is much cleaner than coal and oil, producing about half as much carbon dioxide as combusting coal but it not a long-term solution to the enhanced greenhouse effect

Question 17

Coal, Oil and Gas Compared to Relative Contribution to the Enhanced Greenhouse Effect

Answer 17

Coal: Highest CO₂ emissions, major use in power generation.

Oil: Second highest CO₂ emissions, major use in transportation.

Gas: Lower CO₂ emissions, increasing use in power generation and heating

Question 18

Interactions Between Abioticc Features Influenced by Climate Change

Answer 18

Temperature Changes:
Impact:
~ Rising global temperatures cause various changes in the environment.
Results:
~ Increased temperatures lead to altered weather patterns and prolonged heatwaves.
~ Affects the distribution of species and ecosystems, as some species may migrate to cooler areas while others may face extinction.
Extreme Weather Events:
Impact:
~ Climate change intensifies the frequency and severity of extreme weather events.
Results:
~ More frequent and severe hurricanes, storms, floods, droughts, and wildfires.
~ Damage to infrastructure, agriculture, and natural ecosystems, leading to economic losses and human displacement.
Melting Ice Caps:
Impact:
~ Higher temperatures cause ice caps and glaciers to melt at an accelerated rate.
Results:
~ Contributes to sea level rise, which threatens coastal communities and ecosystems.
~ Loss of habitat for polar species like polar bears and seals, and affects global ocean currents and weather patterns.
Sea Level Rises:
Impact:
~ Melting ice caps and thermal expansion of seawater due to warming lead to rising sea levels.
Results:
~ Increased flooding and erosion of coastal areas, putting infrastructure and human settlements at risk.
~ Salinization of freshwater sources and agricultural lands, impacting drinking water and food production.
Interaction:
~ Rising temperatures and melting ice caps contribute to sea level rise.
~ Extreme weather events become more frequent and intense due to higher temperatures and changing atmospheric conditions.
~ Sea level rise exacerbates the impact of storms and flooding, amplifying the damage caused by extreme weather events.

Question 19

Climate Change Linking to Habitat Loss and Extinction

Answer 19

Temperature Change:
- Species adapt to specific temperatures adn when it changes the species coul struggle to survive.
Weather Patterns:
- Change in weather patterns cause extreme weather and natural disasters like droughts, floods and storms disrupting habitats
Rising Sea Levels:
- As ice melts, water levels rise, flooding coastal habitats and low lying areas like mangroves and weltands
Ecosystem Dynamics:
- Can alter the timings of biological events like flowering, migration and breeding cycles. Leads to decline of species if they can’t adapt fast enough
Increased Frequency of Extreme Events:
- More frequent wildfires, hurricanes/cyclones and heat waves which destroys habitiats and directly kills animals and plants, pushing species into extinction.

Question 20

Extinction

Answer 20

Elimination of a species due to environmental changes, evolutionary changes or human interaction and exploitation.

Question 21

Effects on species and genetic biodiversity

Answer 21

DEFINITION:
Biodiversity:
- All forms of life on Earth from plants, to animals and microorganisms. Includes how they interact with each other
Species:
- Various species in a specific region, area or ecosystem.
Genetic:
- Biological variety of genes in a species
EFFECT:
Species Biodiversity:
Habitat loss:
- Changes in temperature and precipitation patterns can lead to the destruction or alteration of habitats.
- Species that rely on specific conditions may face extinction if they cannot adapt or migrate.
Migration and Range Shifts:
- Many species are forced to migrate to cooler areas, often poleward or to higher altitudes, to find suitable living conditions.
- This can lead to competition with local species and disrupt existing ecosystems.
Genetic Biodiversity:
Evolutionary Pressure:
- Climate change can exert selective pressure on species, favoring those with traits that help them survive in new conditions.
- This can lead to rapid evolutionary changes, but not all species have the genetic variability to adapt quickly enough.
Hybridization:
- As species migrate and overlap in new areas, hybridization can occur, leading to new genetic combinations.
- While this can introduce beneficial traits, it can also dilute species-specific adaptations and lead to loss of unique species.
Combined Impact:
- Ecosystem Disruption: The combined effects on species and genetic biodiversity disrupt entire ecosystems, altering food webs, nutrient cycles, and ecosystem services.
- Loss of Ecosystem Services: Biodiversity supports critical ecosystem services such as pollination, water purification, and climate regulation. The loss of biodiversity can impair these services, affecting human well-being.

Question 22

Value of Biodiversity

Answer 22

Food: Biodiversity is crucial for agriculture, providing a wide range of crops and livestock, and supporting pollinators that are vital for food production.
Medicines: Many medicinal compounds are derived from plants, animals, and microorganisms. Biodiversity is a vast source of potential new medicines and treatments.
Diversity of Species: A variety of species ensures that ecosystems are more resilient to disturbances like climate change, diseases, and extreme weather events.

Question 23

Value of Natural Ecosystems

Answer 23

Water Purification: Wetlands and forests filter pollutants and sediments from water, ensuring clean water supplies for human use.
Cultural Significance: Many cultures have deep connections with nature and specific species, which are integral to their identity and traditions.
Oceans: Oceans absorb and store large amounts of heat, regulating the Earth’s climate and weather systems.