Unit 1: Environmental Studies

Biosphere

Contains all of the planet’s living organisms and covers all areas of the Earth and its atmosphere that contain life.

Atmosphere

All the Earth’s gases above the surface.

Hydrosphere

Contains all the Earth’s water including saltwater and freshwater bodies, rain, glaciers and underground deposits.

Cryosphere

Contains all the Earth’s frozen water.

Lithosphere

Made up of the Earth’s crust and uppermost mantle. Includes all rocks and geological structures on which life exists such as soil, rocks and mountains. 100km thick, divided into tectonic plates which can move and cause earthquakes.

Troposphere

Lowest part of the atmosphere, where the weather occurs. 6-7km thick and sits under the stratosphere.

Stratosphere

Contains 90% of the ozone layer and is 50 km thick. Allows visible infra-red radiation through but absorbs some UV radiation. Stabilises the temperature of the troposphere preventing extreme heat and cold.

Hydrosphere interactions

Water is transported by wind and clouds when it leaves the hydrosphere and enters the atmosphere, returns to the hydrosphere as rain, snow or hail.

Carbon cycle

The process where carbon moves through Earth’s spheres. The amount of carbon on Earth remains the same and continues to cycle.

Photosynthesis

The absorbtion of CO2 from the atmosphere by plants. CO2 is absored from the atmosphere and returned to the biosphere.

Respiration

Carbon stored in plants is passed along in food chains from producers to consumers. CO2 is released into the atmosphere from the biosphere. Energy is consumed and carbon dioxide is produced.

Combustion

The burning of organic matter releases CO2 into the atmosphere.

Decomposition

Dead matter is broken down by decomposers and carbon is released and returned to the atmosphere through respiration.

Ocean atmosphere exchange

CO2 is absorbed by the cool ocean surfaces and released back into the atmosphere by warmer ocean surfaces.

Organic carbon

Found in plants, animals and soil.

Inorganic carbon

Found in water, the atmosphere, minerals and rocks, e.g. CO2

Carbon sink

Any feature of the environment that absorbs and or stores carbon, keeping it from the atmosphere.

Geological carbon cycle

A long term cycle that occurs over hundreds to millions of years. Has resulted in the bulk of carbon being stored in rocks or sediments as fossil fuels.

Biological/physical carbon cycle

Short term cycle that occurs over days, weeks, months and years. Involves the cycling of carbon through photosynthesis and cellular respiration.

How do humans use the geological carbon cycle to their advantage & impact on the environment.

By extracting oil, natural gas and coal (hydrocarbons). Coupled with deforestation, the increase in carbon dioxide has led to an enhanced greenhouse effect, altering temperatures and rainfall paterns.

Other forms of carbon storage

• Decomposed organic matter

• Rocks

• Organic matter in soil

• Dissolved carbon dioxide in oceans and waters

• Shells of marine organisms and some terrestrial organisms

The greenhouse effect

The natural warming of the Earth through the Earth’s greenhouse gases trap heat radiating from the Earth’s surface. The sun emits short wave radiation that passes through the Earth’s atmosphere, some is absorbed by Earth’s sphere and the Earth, and some is re-emitted into the atmosphere.

The enhanced greenhouse effect

Human induced and human actions that are increasing the amount of greenhouse gases in the atmosphere. Increasing the amount of greenhouse gases in the atmosphere where balance is lost. It can be reversed.

Ozone layer

A part of the atmosphere with a large amount of Ozone, which abosrbs some short wave radiation. Has nothing to do with the greenhouse effect.

Role of ice in the greenhouse effect

Ice reflects light and can reflect UV radiation. When ice is melted, the Earth absorbs and re-emmits heat and increases the temperature of the atmosphere.

Effect of EGE on permafrost

When permafrost thaws, organic material breaks down and releases carbon dioxide and methane, also increasing atmospheric temperature.

Positive feedback loop

When a change in a system results in more of the change.

Result of EGE on weather

Increased energy in the atmosphere from increased greenhouse gases means more energy in the weather, resulting in more violent and dangerous weather events.

Sublimation

Turns frozen water directly into water vapor gas.

Precipitation

In the sky where it is colder than the Earth’s surface, water vapor transforms into water droplets (clouds). When the droplets combine together and are too heavy to stay in the air, they fall in the form of rain, sleet, snow and hail, among other things.

Evaporation

Changes liquid and frozen water into water vapor, where it rises to the skies for condensation and precipitation to occur.

Condensation

Once water vapor is in the skies where it is cooler, it condenses back down into water droplets, eventually forming clouds.

Run off

Water runs off the Earth’s surface.

Infiltration

Water sinks into the ground after precipitation.

Plant uptake

Through their roots, plants use the water in the ground after infiltration to convert into energy (glucose).

Evapotranspiration

Due to microscopic holes in plants leaves, water is able to evaporate through them which is known as transpiration.

Volcanic steam

Volcanoes and geysers release steam into the air, which rises and becomes clouds.

Groundwater flow

Underground water as a result of infiltration flows sideways and downwards due to gravity.

Irrigation and agriculture

Humans move water from natural water bodies and ground water systems to water and grow crops. Humans also use fertilisers and pesticides that end up mixing with water, contaminating it.

Deforestation

The clearing of a wide area of trees.

Urbanisation

The population shift from rural to urban areas.

Why is the water cycle considered a global system?

It is active across all spheres, the water evaporated from the ocean can fall onto land, which through run off can flow back into the ocean. Air currents can circulate water and water vapor around the glove.

What does it mean if the natural water cycle is balanced?

Evaporation rates are roughly equal to precipitation rates (globally). Effected by natural changes in climate due to time of year.

Irrigation and agriculture effect on hydrosphere

Alters the flow of water back to the ocean via the rivers water is removed from.

Irrigation and agriculture effect on atmosphere

Spray irrigation increases evaporation in some areas and removal of water from rivers decreases evaporation in other areas, changing location of water vapor in the atmosphere.

Irrigation and agriculture effect on biosphere

Adding fertilisers changes the quality of water downstream available for plants and aminals. It also causes algae blooms and animal and plant deaths.

Irrigation and agriculture effect on lithosphere

The removal of groundwater changes the amount of water flowing back to the hydrosphere.

What are the goals of the Tiwi Carbon Study?

To help Tiwi people emerge into the new carbon economy, to reduce the amount of carbon pollution that occurs when Tiwi land is burnt each year.

What greenhouse gases are released during burning of Tiwi landscapes?

Methane and nitrous oxide.

Where is carbon currently stored?

In the soil and leaves.

Where does the CSIRO want the majority of carbon to be stored? How is it measured?

In the soil. By measuring how much carbon is in the soil samples.

How is carbon currently released?

Leaves store the carbon and is released when burnt.

How to proposed Tiwi island fire practices have a positive impact of reducing the amount of carbon released into the atmosphere?

Small fires help prevent catastrophic fires and therefore less carbon and greenhouse gases are released.

What are the projected savings of carbon (tonnes)?

100 tonnes of carbon is stored in 1 hectare of Tiwi land. If reduced to 1 fire every 4-6 years they can save 4x what is stored and what would be released in the smoke.

Climate change

A long term change in the Earth’s overall temperature with massive and permanent ramifications.

What is the main cause of climate change?

Human activity

How do large amounts of carbon dioxide affect the atmosphere?

Can cause more heat from the Suns rays to become trapped on Earth, heating up the atmosphere.

What 3 main human activities are contributing to climate change?

Fossil fuel burning, animal farming, agriculture, deforestation, waste and recycle pollution.