Environmental Threats to the Planet (Australia)

Question 1

What is a glacial?

Answer 1

When ice is advancing from the poles

Question 2

What is an interglacial?

Answer 2

When ice is retreating from the poles

Question 3

What is an ice age?

Answer 3

When there is permanent snow and ice on the planet

Question 4

What are features of a glacial?

Answer 4

1. Landmass covered with more ice sheets or glaciers
2. Sea level drops
3. Less vegetation
4. Cold temperatures
5. Dry weather
6. Low rainfall

Question 5

What are features of an interglacial?

Answer 5

1. Landmass covered with less ice sheets or glaciers
2. Rising sea level
3. More vegetation
4. Warm temperatures
5. Wet/humid weather
6. Heavy rainfall

Question 6

What was the climate in the Medieval Warm Period (800-1300) like?

Answer 6

A lack of volcanic activity was prevalent between 900-1100 and 1000-1300 was a period of stability, peace and prosperity called the ‘High Middle Ages’

Question 7

What was the climate in the Little Ice Age (1300-1800) like?

Answer 7

Changes in ocean circulation patterns brought cooler sea water into the North Atlantic which decreased temperatures. Several major volcanic events in the 1200s covered the sky in ash and Arctic sea-ice thickened. Huge famines covered Europe and North America and the Black Death killed an estimated 75 million people, linked to weaker immune systems from colder climates

Question 8

What was the climate in the Modern Warming period (1800-2000) like?

Answer 8

The Industrial Revolution began in its earnest in the early 1800s. This was the start of the mass burning of fossil fuels. In 1927, the Earth’s population was 2bn but by 2011 there were 7bn, causing a huge increase in greenhouse gas emissions. Temperatures have changed so rapidly that ecosystems are put under stresses never experienced before with large numbers of flora and fauna going extinct as they are unable to adapt quick enough

Question 9

What are temperature records?

Answer 9

Temperature records began back in the 1850s where actual instrumental records from weather stations and satellites were taken

Question 10

What are the advantages of temperature records?

Answer 10

Technology is so advanced that thermometers are often really cheap and accurate

Question 11

What are the disadvantages of temperature records?

Answer 11

In LIDCs, there’s a lack of equipment and in areas like Antarctica or oceans, there is a lack of equipment or it’s difficult to access

Question 12

What are ice cores?

Answer 12

Ice cores work by drilling through ice until it reaches the bottom. They then measure the greenhouse gases in each layer of the ice and it tells us the concentration of each gas in the atmosphere at that time

Question 13

What are the advantages of ice cores?

Answer 13

It represents a good global average

Question 14

What are the disadvantages of ice cores?

Answer 14

There are only few places around the globe where we can get ice cores from (Antarctica and Greenland) which can be expensive and time consuming

Question 15

What are tree rings?

Answer 15

The study of the growth of rings in trees. It gives us information on previous climates - if the rings were smaller, the year was cooler and wetter and vice versa

Question 16

What are the advantages of tree rings?

Answer 16

It’s a good indication of climate change and how it has changed over time

Question 17

What are the disadvantages of tree rings?

Answer 17

It’s hard to know what caused a tree ring to grow poorly. It could’ve been the temperature or climate

Question 18

What are historical records?

Answer 18

In the past, people kept records such as paintings and diaries

Question 19

What are the advantages of historical records?

Answer 19

People mostly painted in a realism style so it’s unlikely that there was much exaggeration

Question 20

What are the disadvantages of historical records?

Answer 20

We will never know whether artists exaggerated scenes in paintings

Question 21

What are some theories of natural causes of climate change?

Answer 21

1. Changes in the Earth’s orbit
2. Sunspots
3. Volcanic activity

Question 22

What is the changes in the Earth’s orbit and how can they affect the climate?

Answer 22

Milankovitch cycles occur where the Earth’s orbit changes from being more elliptical to being more circular and back again, cycling every 100,000 years. This is because of the gravitational pull of Jupiter and Saturn, causing less solar radiation and cooler temperatures

The Earth also tilts from a variation of 21.5-24.5 degrees every 41,000 years due to the collisions it suffered in its formation. Smaller tilts mean less noticeable seasons and lower average temperatures

Question 23

What are sunspot cycles and how can they affect the climate?

Answer 23

Sunspots are regions on the surface of the sun that are temporarily cooler and therefore appear darker than surrounding regions. At the same time, there are solar flares, which are brief eruptions of intense, high-energy radiation from the sun’s surface which peaks every 11 years. This causes more solar energy and higher temperatures

Question 24

What are major volcanic eruptions and how can they affect the climate?

Answer 24

When major volcanic eruptions occur, it causes cooler temperature as ash and gases are ejected into the stratosphere, leading to more solar radiation being reflected back into space and less reaching the Earth’s surface. Furthermore, sulfur dioxide gas reacts with water to form a cloud of sulfuric acid known as a stratospheric aerosol which can last 1-2 years. This means that temperatures decrease after an eruption

Question 25

What is the greenhouse effect?

Answer 25

1. Heat in the form of short-wave solar radiation travels some distance to reach the Earth's outer atmosphere 2. Radiation that reaches the Earth warms up the surface 3. This warmth is then released in the form of long-wave infrared radiation which is easily absorbed by greenhouse gases, particularly carbon dioxide, methane and nitrous oxide with some escaping into space 4. The radiation is then reflected back towards the surface of the earth, keeping it warm

Question 26

What is the enhanced greenhouse effect?

Answer 26

Human activities such as burning fossil fuels, deforestation and emissions from vehicles have increased the concentration of the greenhouse gases in the atmosphere

Question 27

What is coral reef bleaching?

Answer 27

Coral reefs are important parts of the ecosystem, housing 25% of all marine life. Higher temperatures cause coral polyps to expel algae, causing bleaching

Question 27

What are extreme weather events?

Answer 27

Climate change leads to more frequent extreme events such as cyclones and typhoons.

Question 27

What are the impacts of coral reef bleaching?

Answer 27

1. Less carbon dioxide absorbed by the algae for photosynthesis 2. Coral destroyed, leading to destruction of habitats of marine life 3. Local tourism impacted and jobs at risk 4. In 2022, coral bleaching affected 91% of the Great Barrier Reef

Question 27

What are the consequences of extreme weather events?

Answer 27

1. In 2013, Typhoon Haiyan struck the Philippines, resulting in more than 6000 deaths and $12.9bn total in damages and losses 2. Impacts on economy 3. Strain on government, rescue authorities and healthcare infrastructure

Question 28

How does the global atmospheric circulation work?

Answer 28

1. Air is hottest at the equator because it receives the most solar radiation, making it rise 2. The rising air cools and condenses, causing rain 3. The air spreads east and west at the tropopause, cooling and sinking down at each tropic because it is more dense 4. As the air sinks, it warms up as there is no condensation

Question 29

Why is Oymyakon the coldest region on earth?

Answer 29

It has a high latitude so it receives a low concentration of solar radiation. It also lies on the polar cell where cold air sinks

Question 30

Why is the Lut Desert the warmest region on earth?

Answer 30

It has a low latitude so it receives more concentrated solar radiation. It also lies on warm, sinking air where there's high pressure so it is very hot and dry

Question 31

Why is the Atacama Dessert the driest region on earth?

Answer 31

It's on the edge of the Hadley cell where there is hot, dry and sinking air. It also has a low latitude so it receives a high concentration of solar radiation. The Andes also run all the way down the west coast of South America, creating a rain shadow

Question 32

Why is Ureca, Equatorial Guinea the wettest region on earth?

Answer 32

It lies on the equator where there is low pressure so rising air which condenses to form rain. Also, anything brought along by the Atlantic ocean is dropped onto Equatorial Guinea

Question 33

Why is Antarctica the windiest region on earth?

Answer 33

It lies on the edge of the polar cell where there is cold, falling air