Global warming

What roles do greenhouse gases play in relation to solar radiation

• They absorb, reflect, and scatter incoming solar radiation

What does water vapour do with heat radiated from Earth’s surface

• It absorbs the heat and radiates it in all directions

How does carbon dioxide interact with Earth's radiated heat

• It absorbs the heat radiated from the Earth’s surface

What percentage of incoming solar radiation is reflected back to space by clouds and atmospheric particles

• 26%

What percentage of solar energy is absorbed by clouds, gases, and particles in the atmosphere

• 19%

How much of the incoming solar energy passes through the atmosphere

• 55%

What percentage of solar energy is reflected from Earth’s surface back to space

• 4%

How much solar energy is absorbed by Earth’s land, oceans, and vegetation

• 51%

What does the absorbed solar energy on Earth power

• It heats Earth’s surface, melts ice and snow, evaporates water, creates wind and currents, and fuels photosynthesis

What type of radiation is mainly absorbed at Earth's surface

• Visible light from solar radiation

What happens after Earth’s surface absorbs solar radiation

• The surface warms and re-radiates heat as longwave infrared radiation

What absorbs most of the infrared radiation emitted from Earth’s surface

• Greenhouse gases in the troposphere

What percentage of Earth’s infrared radiation is absorbed and re-emitted by greenhouse gases

• About 90%

What is the result of greenhouse gases re-emitting infrared radiation back to Earth

• The greenhouse effect, which warms the Earth’s surface

What is the source of all radiation and energy reaching Earth

• The Sun

What happens to sunlight when it reaches different landscapes on Earth

• Part is absorbed and part is reflected back (depending on surface type

Which surfaces have high reflectivity (albedo)

• Bright surfaces like ice and snow

Does reflection occur only at Earth’s surface

• No, it also occurs at the top of clouds

Where does absorption of sunlight occur

• At Earth's surface and by gases and particles in the atmosphere

What type of radiation does Earth emit after warming up

• Longwave infrared radiation

What process uses some of the Sun's energy on Earth's surface

• Evaporation of water

What do clouds do with infrared radiation

• Absorb and re-emit it back to Earth, acting like a blanket

Why are deserts often cold at night

• Lack of clouds to trap infrared radiation

What do greenhouse gases do with Earth's infrared radiation

• Absorb and retain the heat near the surface

Describe and draw the diagram

1.The sun is the source of all radiation and energy coming to the Earth from space.

2.A part of the sunlight reaches the Earth surface and all its different landscapes: forests, oceans, deserts, savannah, cities, ice and snow

3.The Earth's surface does not take up all the sunlight, but sends a certain part of it directly back (reflection). In particular very bright surfaces like ice and snow are excellent reflectors (albedo).

4.Reflection does not only occur at the Earth surface. Some light is already sent back from the top side of clouds.

5.The uptake of the light (absorption) does not only take place at the Earth surface, but gas molecules and particles in the air absorb some sunlight. The portion of the sunlight reaching the Earth warms up the surface. The Earth sends this warmth back as infrared radiation.6.The Earth's surface warmed up by the sun is a source of heat radiation (long wave infrared radiation).

7. A bit of the energy is needed to evaporate water.

8.Some infrared radiation goes directly back to the space.

9.Clouds do not only reflect sunlight, they also absorb and reemit infrared radiation back to the Earth. A cloudy sky keeps the Earth warmer, like a blanket (part of the reason why deserts are cold at night are because of no clouds).

10.Finally there are greenhouse gases that absorb the infrared radiation given off. They keep the energy of this heat radiation near the ground.

Why aren’t nitrogen and oxygen considered greenhouse gases

• Because they do not have two or more bonds and cannot absorb and re-emit infrared radiation

What property must a molecule have to absorb and re-emit infrared radiation

• It must have two or more bonds joining the atoms

What are the three most important greenhouse gases

• Water vapour

• Carbon dioxide (CO₂)

• Methane (CH₄

Which greenhouse gas contributes the most to the greenhouse effect

• Water vapour

What is the structure of a carbon dioxide (CO₂) molecule

• One carbon atom with an oxygen atom bonded on each side

What happens when carbon dioxide absorbs infrared radiation

• The molecule vibrates and then emits the radiation again

What happens to the emitted radiation from a vibrating greenhouse gas molecule

• It is likely absorbed by another greenhouse gas molecule

How does the absorption-emission-absorption cycle affect Earth’s temperature

• It keeps heat near the surface, insulating Earth from the cold of space

What causes the enhanced greenhouse effect

• Human activities that increase greenhouse gas concentrations in the atmosphere

What are some human activities that increase greenhouse gas emissions

• Burning of biomass and fossil fuels

• Agricultural activities

• Industrial processes

How does deforestation contribute to the enhanced greenhouse effect

• It reduces carbon sinks, meaning less carbon dioxide is absorbed from the atmosphere

What are carbon sinks

• Natural systems like forests that absorb more carbon than they release

Enhanced greenhouse effect diagram

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Which greenhouse gases have increased due to human activity

• Carbon dioxide (CO₂)

• Methane (CH₄)

• Nitrous oxide (N₂O)

• Ozone (O₃)

• Synthetic gases like CFCs and halons

Which greenhouse gas has contributed the most to the enhanced greenhouse effect

• Carbon dioxide (CO₂)

By how much has the greenhouse effect increased since pre-industrial times

• By approximately one-third

How much has atmospheric CO₂ increased in the past 20 years

• By 30 parts per million (ppm)

What are CFCs and halons

• Synthetic greenhouse gases introduced by humans that contribute to the enhanced greenhouse effect

What are examples of land use changes

• Back burning and land clearing for pastoral purposes

What does land use change directly affect

• Albedo

• Transpiration rates

• Carbon dioxide sources and sinks

How do changes in polar regions affect global warming

• They cause feedback effects that lead to further warming of the planet

What happens when ice and snow melt due to rising temperatures

• Less sunlight is reflected (lower albedo), and more is absorbed by land and sea, increasing warming

What is the albedo effect

• The fraction of solar energy reflected by a surface

• Bright surfaces like ice have high albedo; darker surfaces absorb more heat

What is the main cause of global warming

• More infrared radiation being absorbed and re-emitted in the troposphere

How does global warming affect global climates

• It changes temperatures and ocean/atmospheric circulation patterns

How does global warming affect precipitation patterns

• Some regions experience more precipitation, others experience less

How are soil moisture levels affected by global warming

• They change due to altered precipitation and evaporation rates

What causes rising sea levels

• Melting land ice and thermal expansion of seawater

What extreme weather events are becoming more frequent due to global warming

• tropical storms

• droughts

• floods

• forest fires

What does Earth's temperature depend on

• The greenhouse-like action of the atmosphere

What strongly influences the amount of heating and cooling on Earth

• The type of surface solar radiation encounters

What is albedo

• The percentage of solar energy reflected back by a surface

How does a white icy surface affect solar radiation

• It reflects most sunlight, causing minimal heating

How does dark, bare soil affect solar radiation

• It absorbs most sunlight, contributing to significant surface heating

How does water vapour affect solar radiation

• It reduces the amount of radiation reaching the surface but also acts as a greenhouse gas

What is the relationship between water vapour and air temperature

• The amount of water vapour in the atmosphere depends heavily on air temperature

Why is the extent of the enhanced greenhouse effect complex

• Because it’s influenced by surface types, albedo, water vapour, and cloud cover

How does climate change affect global temperatures

• Increases average temperatures, causing more frequent and intense heatwaves

What causes sea level rise due to climate change

• Melting glaciers and ice sheets, and thermal expansion of ocean water

What are the effects of rising sea levels

• Erosion of beaches, inundation of coastal lands, and increased cost to protect coastal communities

How does climate change affect precipitation patterns

• Increases variability—some areas get more intense rainfall while others experience droughts

What are some health impacts of climate change

• Increased weather-related mortality

• More infectious diseases

• Poorer air quality causing respiratory illnesses

How does climate change impact agriculture

• Alters crop yields

• Increases irrigation demands

• Shifts growing seasons and crop suitability

How are forests affected by climate change

• Changes in forest composition

• Shifting geographic ranges

• Declines in forest health and productivity

What are climate-related impacts on water

• Reduced water supply

• Lower water quality

• Increased competition for water

How are coastal areas impacted by climate change

• Erosion of beaches

• Coastal flooding

• Increased infrastructure costs

How does climate change affect ecosystems

• Habitat loss

• Species extinction or migration

• Reduced biodiversity

What is happening to Earth’s cryosphere due to climate change

• Diminishing glaciers, melting permafrost, and loss of polar ice

How do scientists know that climate has changed over millions of years

• Fossil records show that Earth’s climate has varied naturally over time, even before humans existed

What does recent climate data show

• A steady, small increase in global average temperatures over the past few decades based on worldwide weather data

What do most scientists believe is causing recent global warming

• Anthropogenic (human-caused) activities such as burning fossil fuels and deforestation

Why is this recent warming concerning

• Although within the range of past natural variability, the rapid pace and human influence make it a major environmental concern

How will climate change affect the natural environment

It will cause:

• Migration, population decline, and extinction of plant and animal species.

• Shifts in habitats and ecosystems due to temperature and water changes.

How will climate change impact humans

It may lead to:

• Reduced water availability

• Loss of coastal areas due to rising sea levels

• Spread of diseases

• Negative effects on industries like agriculture, fishing, and tourism that rely on stable climate and natural resources