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Chris Kanubaddi - Science Sem2 > Climate Change > Flashcards

Climate Change Flashcards

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1
Q

What defines the Anthropocene era?

A

Humans dominate and disrupt natural systems, advancing technology to mass-produce goods while increasing waste and dependence on fossil fuels.

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2
Q

What issue arises from disposable goods?

A

Disposable goods lead to waste disposal challenges, depletion of natural resources, and sustainability concerns.

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3
Q

How do fossil fuels impact climate change?

A

Burning fossil fuels releases CO₂ and other greenhouse gases, trapping heat in the atmosphere, leading to global warming and extreme weather patterns.

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4
Q

How is society addressing climate change?

A

Through recycling, adopting electric vehicles, sustainable food production, and demanding government policies to reduce carbon footprints.

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5
Q

What challenge does the current generation face?

A

Addressing the environmental and societal consequences of past actions, including nuclear disasters and large-scale pollution.

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6
Q

Why are scientists studying Antarctic ice?

A

To assess how melting ice affects global sea levels, weather systems, and the Earth’s climate as a whole.

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7
Q

How does melting ice affect Earth’s temperature?

A

Less reflective ice exposes darker surfaces (land/water), which absorb sunlight, increasing Earth’s temperature and accelerating further ice melt.

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8
Q

What accelerates Antarctic ice melting?

A

Rising air and ocean temperatures increase water flow, destabilizing ice sheets and melting more ice, creating a feedback loop.

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9
Q

What tools are used to study melting ice?

A

Advanced computer models and data analysis predict atmosphere-ocean interactions causing ice melt and inform climate change strategies.

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10
Q

What are the four spheres of Earth?

A

Hydrosphere: All water on Earth
Lithosphere: Earth’s outermost rocky layer
Atmosphere: Layer of gases around Earth
Biosphere: All living things and ecosystems on Earth

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11
Q

How do Earth’s spheres interact?

A

Earth’s spheres influence and interact with each other, affecting natural processes and systems.

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12
Q

What is the biosphere?

A

The biosphere is the layer where life exists, including all living organisms (biota) and ecosystems.

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13
Q

What are biomes?

A

Biomes are regions influenced by environmental factors like latitude, temperature, and rainfall, defined by dominant vegetation.

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14
Q

What is the hydrosphere?

A

The hydrosphere includes all of Earth’s water, which moves through different states via the water cycle.

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15
Q

What is the lithosphere?

A

The lithosphere is Earth’s rocky crust and soil, made of igneous, sedimentary, and metamorphic rocks.

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16
Q

What are ecosystems?

A

Ecosystems are smaller regions within biomes where organisms interact in a specific environment.

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17
Q

What are the 5 layers of the atmosphere?

A

Troposphere
Stratosphere
Mesosphere
Thermosphere
Exosphere

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18
Q

What are in each of the 5 layers of the atmosphere?

(DONT NEED TO KNOW FULL DESCRIPTIONS).
- just get an understanding.

A

Troposphere: The first atmospheric layer, closest to Earth’s surface, containing 75% of the atmosphere’s mass and tightly packed air particles.

Stratosphere: The second layer, about 55 km above Earth, contains the ozone layer, which absorbs UV radiation and lets visible light through.

Mesosphere: The third atmospheric layer, with temperatures from 0 to -90˚C, where meteors burn up.

Thermosphere: The fourth atmospheric layer (80-500 km) contains the ionosphere, crucial for transmitting radio waves.

Exosphere: The outermost atmospheric layer, 500+ km above Earth, blending into outer space.

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19
Q

In which forms is carbon found in Earth’s spheres?

A

Hydrosphere: Dissolved carbon dioxide
Lithosphere: Coal, oil, limestone
Atmosphere: Methane, carbon dioxide
Living things: Proteins, carbohydrates, lipids

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20
Q

What is the carbon cycle?

A

The carbon cycle explains how carbon moves through the biosphere, transferring between non-living (atmosphere) and living things (organisms) via photosynthesis and respiration.

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21
Q

What happens to carbon in photosynthesis?

A

Plants absorb carbon dioxide from the atmosphere and, with water and sunlight, convert it into glucose and oxygen.

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22
Q

What is the equation for photosynthesis?

A

Carbon dioxide + water + sunlight → glucose + oxygen

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23
Q

Why is nitrogen important?

A

Used in DNA and proteins (enzymes, hormones)
Plants need it for chlorophyll (photosynthesis)

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24
Q

Why can’t nitrogen be used directly from the atmosphere?

A

Atmospheric nitrogen (N₂) must be converted to usable forms, as most organisms cannot directly use it.

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25
Q

What is the nitrogen cycle?

A

The nitrogen cycle explains how nitrogen is converted and cycled through the biosphere to support DNA, proteins, and chlorophyll production.

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26
Q

What is nitrogen fixation?

A

Fixation is the process where bacteria convert atmospheric nitrogen (N₂) into ammonium, making it usable by plants.

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27
Q

What is nitrification?

A

Nitrification is the conversion of ammonium into nitrates by bacteria, which plants can absorb from the soil.

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28
Q

How do plants assimilate nitrogen?

A

Plants absorb nitrates from the soil through their roots and use nitrogen to produce amino acids, nucleic acids, and chlorophyll.

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29
Q

What is ammonification?

A

Ammonification occurs when decomposers convert nitrogen from dead plants and animals into ammonium, allowing it to re-enter the nitrogen cycle.

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30
Q

What is denitrification?

A

Denitrification is when bacteria release extra nitrogen from the soil into the atmosphere.

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31
Q

What does the phosphorus cycle represent?

A

It shows how phosphorus moves through the lithosphere, hydrosphere, and food chains, supporting plant and crop growth.

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32
Q

Why is phosphorus essential for plants?

A

Phosphorus promotes healthy roots, early shoots, better flower and seed production, and improved quality of fruits, vegetables, and grains.

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33
Q

Does phosphorus impact climate change?

A

As phosphorus lacks a primary gaseous form, it has little impact on climate change.

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34
Q

What are some human impacts on Earth’s cycles?

A

Deforestation
Mining
CFCs destroying the ozone layer
Eutrophication from excess fertilizers
Industrial and factory waste pollution
Increased transport which releases more greenhouse gases

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35
Q

What is climate change?

A

Climate change refers to significant long-term differences in a region’s average temperature, recorded over many years.

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36
Q

What are the three major influences on Earth’s climate?

A
  1. Tilt of Earth’s axis and sunlight reaching the surface
  2. Land and water absorbing/emitting radiant heat
  3. Features of the land
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37
Q

How does Earth’s tilt affect climate?

A

Earth’s tilt spreads solar energy unevenly, creating warmer equatorial and colder polar regions and influencing wind patterns.

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38
Q

Why do polar regions have extreme seasons?

A

They experience up to six months with little or no sunlight, while the equator receives consistent radiation year-round.

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39
Q

How do land and water differ in heat absorption and emission?

A

Land absorbs and emits heat faster than water.
Water moderates coastal climates, reducing temperature extremes.

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40
Q

Why are coastal climates milder than inland climates?

A

Water absorbs and radiates heat slower than land, stabilising temperature changes.

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41
Q

How is climate data collected?

A

Using weather stations and space satellites to measure temperature and radiant heat differences.

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42
Q

How does altitude affect temperature?

A

Higher altitudes above sea level experience colder temperatures in the atmosphere.

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43
Q

How do mountain ranges affect climate?

A

Mountains block wind, forcing air upwards to form clouds as water vapour condenses quickly, often creating unique weather patterns.

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44
Q

What land features affect climate?

A

Sandy soils reflect more sunlight than fertile soils.
Fresh snow reflects 90% of solar energy.
Vegetated areas absorb more sunlight for photosynthesis.

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45
Q

What drives ocean currents?

A

Ocean currents are driven by Earth’s rotation and temperature differences between the tropics and poles.

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46
Q

How do ocean currents influence coastal climates?

A

Warm currents (e.g., Gulf Stream) heat coastal areas like Great Britain.
Cold currents cool otherwise hot regions.

47
Q

How does CO2 impact ocean temperatures?

A

CO2 traps heat in the atmosphere, warming oceans and affecting the movement of ocean currents, which distribute solar radiation.

48
Q

What is the Gulf Stream’s role in climate?

A

The Gulf Stream carries warm water from the equator to the North Atlantic, warming regions like Great Britain and Norway.

49
Q

What are the three major ocean currents influencing Australia?

A

East Australian Current
Indonesian Throughflow
Leeuwin Current

50
Q

How do ocean currents affect Australia’s marine environment?

A

Redistribute heat between the ocean and atmosphere
Move heat from warmer to cooler regions globally
Changes in currents lead to marine heatwaves and altered nutrient exchange.

51
Q

What causes wind?

A

Wind is caused by the difference in surface temperature between the poles and tropics, which creates convection currents. Cold air sinks at the poles, and hot air rises at the equator, causing movement.

52
Q

What are prevailing winds?

A

Prevailing winds are the winds most frequently observed in a region, and they are influenced by factors like latitude, Earth’s rotation, tilt, orbit, and land features.

53
Q

What factors complicate the direction of prevailing winds?

A

Latitude
Earth’s rotation, tilt, and orbit
Land friction
Ocean currents
Local air pressure and temperature variations
Water and land temperature differences
Altitude

54
Q

How do prevailing winds affect air temperature?

A

In Australia, northerly winds bring hot, dry air from the north during summer, while southerly winds bring cooler, damp air from the south.

55
Q

How have the climate patterns of La Niña and El Niño changed over the past 50 years?

A

Due to the increase in greenhouse gas emissions, La Niña and El Niño have become more extreme in the last 50 years.

56
Q

What happens during a La Niña event?

A

Stronger trade winds push warm water further west than normal.
An increase in rainfall occurs in Australia, South-East Asia, and southeastern Africa, often leading to catastrophic flooding.
Drought may occur in the southern United States.

57
Q

What happens during an El Niño event?

A

The trade winds weaken or reverse, sending warm water back east.
The warmer water releases more heat into the atmosphere, causing wetter and warmer weather in regions like the south of the United States and the Gulf of Mexico.
Australia, central Africa, and Asia experience drier conditions.

58
Q

What is the greenhouse effect?

A

The greenhouse effect occurs when greenhouse gases trap some of the Sun’s energy, helping to maintain Earth’s warm temperatures, which are crucial for life. Without it, Earth’s average temperature would be –18°C, making life unsustainable.

59
Q

What are the primary greenhouse gases?

A

Carbon dioxide (CO₂): Produced by burning fossil fuels and deforestation.
Methane (CH₄): Emitted by livestock, rice paddies, and landfills.
Nitrous oxide (N₂O): Released from fertilizers and industrial processes.
Water vapour (H₂O): Naturally occurs but is influenced by other gases.
Ozone (O₃): Found in the stratosphere,it absorbs UV radiation.
HFCs (Hydrofluorocarbons): Synthetic gases used in refrigeration and air conditioning, contributing to global warming.
PFCs (Perfluorocarbons): Released during aluminum production and industrial processes, with a high warming potential.

60
Q

How do greenhouse gases affect Earth’s temperature?

A

Greenhouse gases absorb and trap heat in Earth’s atmosphere, which keeps the planet warm enough to support life. Increasing these gases can intensify the greenhouse effect, leading to global warming.

61
Q

What is the Enhanced Greenhouse Effect?

A

The enhanced greenhouse effect is caused by increased greenhouse gases (GHGs) trapping more heat, leading to greater-than-expected warming of the Earth.

62
Q

What human activities contribute to the Enhanced Greenhouse Effect?

A

Activities like burning fossil fuels, deforestation, industrial waste, and population growth have increased GHGs (mainly CO2, N2O, H2O), enhancing the greenhouse effect.

63
Q

What gases are primarily responsible for the Enhanced Greenhouse Effect?

A

The leading gases are carbon dioxide (CO2), nitrous oxide (N2O), and water vapour (H2O).

64
Q

How does cellular respiration contribute to carbon emissions?

A

Cellular respiration produces CO2 when glucose is converted into energy:
glucose + oxygen → CO2 + water + energy.

65
Q

How do fossil fuels contribute to carbon emissions?

A

The combustion of fossil fuels releases CO2, a major greenhouse gas:
hydrocarbon + oxygen → CO2 + water + heat and light.

66
Q

How do ice cores provide evidence for climate change?

A

Ice cores trap ancient air, dust, and gases like CO2, preserving historical climate data and allowing scientists to track past temperatures and GHG concentrations.

67
Q

How does methane contribute to the enhanced greenhouse effect?

A

Methane (CH4) is a potent greenhouse gas, contributing about 20% to the enhanced greenhouse effect, primarily from agriculture, wetlands, fossil fuels, biomass burning, and melting permafrost.

68
Q

What is methane, and where does it come from?

A

Methane is a colourless, odourless, and flammable gas produced by cattle, wetlands, fossil fuel use, biomass burning, and natural emissions, including melting permafrost.

69
Q

How do scientists use climate models?

A

Climate models use computer simulations of air circulation, ocean water movement, and collected environmental data to predict climate change and its impacts.

70
Q

What does climate modelling predict for global temperatures by 2100?

A

Climate models predict a global temperature increase of 1.1 to 5.4°C by 2100, with uneven warming across continents.

71
Q

How might climate change affect Australia by 2070?

A

By 2070, Australia’s temperatures could rise by up to 6°C, leading to more hot days, fewer cold days, altered rainfall patterns, more bushfires, and destructive tropical cyclones.

72
Q

What are palaeoclimates?

A

Palaeoclimates are the study of past Earth’s climates using geological and biological evidence to understand climate changes and transitions over time, aiding in future climate predictions.

73
Q

How do scientists use proxies in palaeoclimates?

A

Proxies are biological, physical, or chemical materials preserved in geological evidence, such as ice cores, tree rings, and coral, used to determine past climates.

74
Q

What is the significance of palaeoclimate studies?

A

Palaeoclimate studies help reconstruct past climates and improve climate models, offering insights into future climate patterns and changes.

75
Q

What is the challenge for climate scientists regarding global warming?

A

The main challenge is predicting climate change and the uncertainty in these predictions, despite 40 years of research finding no evidence against the human-caused hypothesis.

76
Q

Could Earth become too hot for humans?

A

If global temperatures increase by 7°C, many places may become too hot to survive. At 12°C, half of Earth’s land, including Australia, could become uninhabitable due to extreme heat and humidity.

77
Q

What core temperature do humans need to survive?

A

Humans require a core body temperature of around 37°C to function. A rise above 42°C can be fatal.

78
Q

How might humans adapt to extreme heat in the future?

A

Possible adaptations include selecting traits like taller, slimmer body shapes or smaller mammals that better radiate heat and endure heat stress.

79
Q

What diseases might humans face in a hotter world?

A

Increased heat may lead to more diseases, including food poisoning, skin cancers, cataracts, and tropical diseases. Resistance genes may influence survival.

80
Q

How might global warming impact human evolution?

A

Some believe warming could reduce brain size, while others suggest modern brains and technology will buffer humans against heat, allowing cultural adaptation.

81
Q

What does research suggest about the human brain and evolution?

A

Research shows the human brain is still evolving, with recent natural selection on genes regulating brain size, potentially influencing our ability to adapt to climate change.

82
Q

What role does culture play in human adaptation to heat?

A

Culture and technology may provide a buffer against the negative impacts of climate change, allowing humans to adapt to hotter climates despite evolutionary challenges.

83
Q

What was Earth’s early atmosphere like when life first appeared?

A

The early atmosphere was hostile, composed of hydrogen, methane, ammonia, water vapor, and carbon dioxide. There was no oxygen until photosynthetic organisms began producing it.

84
Q

What is biodiversity?

A

Biodiversity refers to the variety of life on Earth, including the diversity of genes, species, and ecosystems. It exists at the genetic, species, and ecosystem levels.

85
Q

Why is biodiversity important for evolution?

A

Biodiversity allows for variation within species, helping some organisms be better suited to their environment, which increases the chance of survival and reproduction.

86
Q

What is genetic diversity?

A

Genetic diversity refers to the variation in genes within a species. This diversity is essential for survival, as some variations may help individuals adapt to environmental changes.

87
Q

How does genetic variation contribute to survival?

A

Genetic variation increases the likelihood that at least one individual in a population will possess traits that allow it to survive and reproduce in changing environments.

88
Q

What is species diversity and why is it important?

A

Species diversity refers to the variety of populations within a species. A diverse gene pool allows for more genetic combinations, increasing the chance of survival for offspring in changing environments. Low variation may lead to extinction.

89
Q

What is a gene pool?

A

A gene pool is the combination of all alleles within a population of the same species, which can be used to produce the next generation. It is crucial for maintaining species diversity.

90
Q

How does genetic diversity affect survival?

A

Greater genetic diversity increases the chance that offspring will inherit traits that allow them to survive environmental changes. Low diversity can reduce survival chances, potentially leading to extinction.

91
Q

What is ecological diversity?

A

Ecological diversity refers to the variety of ecosystems. Higher biodiversity in ecosystems helps mitigate the loss of a species, whereas lower biodiversity can lead to the extinction of other linked species.

92
Q

How does the extinction of one species affect an ecosystem?

A

The extinction of one species can disrupt the food web and threaten the survival of other species within the ecosystem, especially if no other species can take its ecological role.

93
Q

What is the sixth mass extinction, and when did it start?

A

The sixth mass extinction is believed to be caused by human activities. The first phase began about 100,000 years ago with the spread of modern humans, and the second phase started around 10,000 years ago with the advent of agriculture.

94
Q

How has human population growth affected extinction rates?

A

A 2008 study showed that as human population grew, so did the extinction of flora and fauna, highlighting the negative impact of humans on biodiversity.

95
Q

How do temperature changes affect marine life?

A

Temperature changes can disrupt marine species’ food sources, separate species from their habitats, and reduce oxygen levels in ocean water, potentially leading to extinction of some marine life.

96
Q

How have rising sea levels impacted the Earth?

A

Sea levels have risen by 10-20 cm over the past 100 years due to ocean warming, thermal expansion, and melting glaciers. This is expected to continue, further threatening coastal habitats.

97
Q

Why is Arctic sea ice melting and how fast?

A

Arctic sea ice is melting at a rate of 12.6% every ten years, contributing to rising sea levels and habitat loss, especially in polar regions.

98
Q

What is geosequestration and how can it help reduce global warming?

A

Geosequestration involves separating CO2 from flue gases in fossil fuel power stations, compressing it, and storing it in suitable sites like depleted oil and gas wells. It aims to remove CO2 from the atmosphere to reduce global warming.

99
Q

How many sites in Australia are identified for geosequestration and how much CO2 can they store annually?

A

At least 65 suitable sites in Australia can store up to 115 million tonnes of CO2 annually, aiding in the reduction of global warming.

100
Q

What did the 2009 study on wood products in landfill reveal about carbon storage?

A

The study found that at least 82% of the carbon originally in sawn timber remains stored in wood products even after disposal, suggesting that wood can act as a carbon sink.

101
Q

What are carbon sinks, and how do they help combat climate change?

A

Carbon sinks are natural sites that absorb high levels of carbon, removing it from the atmosphere. Forests and wood products can act as carbon sinks, helping to reduce the impact of climate change.

102
Q

Why are renewable resources becoming more important?

A

Renewable resources are gaining importance due to the harmful environmental impact of fossil fuels, which contribute to over 75% of global greenhouse gas emissions. Renewables offer a more sustainable and environmentally friendly alternative.

103
Q

What are some of the main renewable energy sources in Australia?

A

Some of the main renewable energy sources in Australia include solar, wind, and hydro power, providing cleaner alternatives to fossil fuels.

104
Q

How is solar energy converted into electricity, and what affects its efficiency?

A

Solar energy is converted into electricity using solar panels. Their efficiency, typically around 22%, is influenced by factors like location, number of panels, and weather conditions, particularly cloud cover.

105
Q

What are the challenges associated with solar energy?

A

Solar panels require significant space, can only generate electricity during daylight, and their efficiency is impacted by weather conditions, such as cloud cover.

106
Q

How efficient is wind energy, and how is it harnessed?

A

Wind energy is highly efficient, converting between 60-90% of wind energy into power using wind turbines, which work whenever there’s sufficient wind.

107
Q

What are the challenges associated with wind energy?

A

Wind turbines require favorable weather conditions to generate power, are large and may require clearing land for installation, and can pose risks to wildlife, particularly birds.

108
Q

What is the advantage of wind energy compared to solar energy?

A

Unlike solar panels, which only work during the day, wind turbines can generate electricity whenever there’s enough wind, making them a more consistent renewable energy source.

109
Q

How is hydro energy used to generate electricity?

A

Hydro energy generates electricity by placing turbines in the path of flowing water. The water’s movement turns the turbines, which then produce power.

110
Q

What are the limitations of hydro energy generation?

A

Due to their flow and power potential, not all rivers or streams are suitable for hydro energy. Larger hydroelectric power stations often require damming water, which can disrupt ecosystems.

111
Q

What is the environmental impact of damming water for hydro energy?

A

Damming water for hydroelectric power can disrupt ecosystems, affect fish migrations, alter river flow patterns, and reduce water quality.

112
Q

What is the difference between afforestation and reforestation?

A

Afforestation involves planting trees in areas that were not previously forested. At the same time, reforestation focuses on replanting trees in areas where forests have been lost due to activities like logging or wildfires.

113
Q

How do trees help fight climate change?

A

Trees absorb carbon dioxide through photosynthesis, converting it into oxygen and storing carbon in their trunks, branches, and roots, which helps reduce the amount of carbon dioxide in the atmosphere.

Chris Kanubaddi - Science Sem2 (3 decks)

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