The World's Climate System -

What are the two major thing that transfer heat around the earth?

What are the two major thing that transfer heat around the earth?

• The atmosphere

• The oceans

They redistribute heat too different parts of the world

What is the Earth’s climate influenced by?

• The atmosphere

• The ocean

What would happen without the transfer of energy around the globe?

Many parts of the earth would be inhabitable

• The poles will be much colder

• The equator will be much hotter

How is heat transferred around the Earth in the atmosphere?

Circulation cells

How is heat transferred around the Earth by the ocean?

Ocean currents

What does the way our atmosphere circulates around the Earth affect?

• Global weather

• Climate pattern

Why does the way our atmosphere circulate affect global weather and climate pattern?

It is because our atmosphere influences the temperature and humidity

What is the atmosphere?

The layer of air surrounding the Earth’s surface which extends hundreds of kilometers high.

What gas does the atmosphere contain?

• oxygen

• nitrogen

• water vapour

• carbon dioxide

What does our atmosphere contain?

• Gas

• Water droplets

• Particles

Why is the air constantly moving in different directions?

• suns energy

• difference in pressure

• rotation of our Earth

What are the different circulation cells?

• The Hadley cell

• The Ferrel cell

• The Polar cell

What is the Hadley cell?

• Located at the equator

• Hot, moist air rises moves to higher latitudes (30 degrees) and sinks

What is the Ferrel cell?

• At around 60 degrees either side of the equator

• Moist air rises and travels to lower latitudes at around 30 degrees where it sinks, along with air travelling from the equator.

What is the polar cell?

• 60 degree north or south of the equator

• - Moist air rises and travels to the poled (90 degree) where it sinks

Explain the different areas of pressure

• When air rises, it creates an area of low pressure underneath

• When air sinks, it creates an area of high pressure

Explain the pressure difference between the land and the Ocean

In the Land:

• Land generally absorbs sunlight more and heats up quickly in the summer months, causing low pressure over land as the hot air is rising

• In the winter, land loses energy quickly causing high pressure over the land.

In the sea:

• The sea reflects more heat and therefore takes longer to heat up, forming areas of high pressure.

• In winter, the sea takes longer to cool, meaning they are relatively low pressure.

In january, what hemisphere is in the winter and which is in the summer?

• North - Winter

• South - Summer

In july, what hemisphere is in the winter and which is in the summer?

• North - Summer

• South - Winter

Why are pressure belts formed around the globe?

Due to atmospheric cells and pressure difference

What which parts of the Earth are there low pressure?

• Equator

• At 60 degrees either side of the equator

What which parts of the Earth are there high pressure?

• Poles

• 30 degree either side of the equator

When is wind created?

When air particles move

Why doesn’t wind move in a straight line?

This is because the Earth is spinning, so the wind ends up moving in a curved direction.

What is the Coriolis effect?

The Coriolis effect is a phenomenon that causes moving objects, such as air or water, to be deflected in a curved path due to the rotation of the Earth. It is responsible for the rotation direction of cyclones and anticyclones in the atmosphere and the direction of ocean currents.

What way is the wind deflected in the northern hemisphere?

• The wind is deflected right

What way is the wind deflected in the southern hemisphere?

• The wind is deflected left

What are ocean currents?

Ocean currents are the predictable, continuous movements of water in the ocean that are driven by various factors such as wind, temperature, and salinity

Give an example of an ocean current that influences climate?

The gulf stream

Explain how the Gulf Stream influences climate?

Warm water from the equator flows up to the North Atlantic via the Gulf of Mexico, which causes the climate in Europe to be warmer. Without this ocean current, Europe would be 5-10 degrees colder

What are ocean current driven by?

• Winds

• the Coriolis effect

• the Tides

• Density differences (temperature and salinity)

What is the difference between climate and weather?

• Climate is a long term trend in temperature, humidity (usually calculated over a 30 year period or longer)

• Weather is referring to the daily conditions that a place experiences

Where are high rainfall area usually found?

In areas of low pressure.

What is the climate at the equator and why is it like that?

The climate is humid and very rainy

The sun shines directly on the equator, meaning it is consistently warmer Hot warm air rises here, creating an area of low pressure. When moist air rises, it condenses to form rain clouds.

What type of land is found in the equator because of its warm and wet weather?

Tropical rainforest

What is arid?

This is a region that has little rainfall causing it to be dry

Where are the arid areas located on the Earth

In areas of high pressure

Why does having high pressure make a place arid?

This is because clouds to not form there because air isn’t rising and so it is dry

What type of land is found in areas of high pressure?

deserts

What is Inter Tropical Convergence Zone (ITCZ)

The Inter-Tropical Convergence Zone is an area surrounding the equator where winds from the northern and southern hemisphere meet (converge) causing an area of low pressure with rainy conditions.

What is the pattern of ITCZ?

• They move seasonally

• January - Close to the Tropics of Capricorn and the maximum south is -20 degrees

• July - Close to the Tropics of Cancer and the maximum north is -25 degrees

What are the natural causes of climate change?

• Asteroid collisions

• Variations in the Earth's orbit around the Sun (Milankovitch Cycles)

• The effects of volcanic eruptions

• Changes in the solar output (amount of heat energy) of our Sun

Explain the Asteroid collision theory and how it can impact climate change?

• If an asteroid is large enough, millions of tons of ash and debris will be ejected into the atmosphere when it hits Earth.

• This material will block out the sun and therefore cause global temps to be much lower.

• Scientist theorise that it was a huge asteroid collision that led to the ice age and the extinction of the dinosaurs.

Explain the Orbital changes in the Earth/Milankovitch cycles and how it can impact climate change?

Orbital Changes:

• The way the earth orbits around the sun changes every thousand of years.

• These changes affect where the Sun hits Earth, and how intense the Sun is, which in turn controls the season and affects the climate.

• Orbital changes follow very similar patterns to glacial and interglacial periods

• Scientist theorise that orbital changes caused major temperature fluctuations throughout Earth’s history.

Milankovitch cycles:

• The Milankovitch cycles refer to long-term variations in Earth's orbit around the Sun, which can impact climate change.

• It was discovered by Serbian geophysicist Milutin Milankovitch

• There are three main components of these cycles: eccentricity, axial tilt, and precession.

• These orbital changes can impact climate change by altering the distribution and intensity of solar radiation reaching Earth's surface. They can influence the amount of energy available for processes such as evaporation, ocean currents, and atmospheric circulation, ultimately affecting global climate patterns over long periods of time.

What are the 3 orbital changes the Earth goes through?

• Eccentricity

• Obliquity

• Precession

Explain the orbital change: Eccentricity?

• The orbit of the Earth around the Sun changes from a near-perfect circle to an ellipse (squashed circle/oval).

• This affects how intense the Sun's rays are on Earth. If the Earth is orbiting in an elliptical shape, it will be further away from the Sun at certain points than if it was orbiting in a circle.

• 1 cycle takes around 100,000 years.

Explain the orbital change: Obliquity?

• The tilt of the Earth's axis, which changes from 21.5° and 24.5° (currently 23.5°).

• Affects the contrast between summer and winter seasons.

• To change between 21.5° and 24.5° takes around 41,000 years.

Explain the orbital change: Precession?

• Describes the wobble of the Earth's axis - like a spinning top

• Affects the length of days, especially in the poles.

• A full cycle takes just over 20,000 years.

Explain the Solar Output and how it can impact climate change?

• There are variation in the amount of solar energy that the Sun emits which are thought to have an effect on the Earth’s climate.

• One Variation - sunspot cycles

  • A sunspot cycle is an 11 year cycle where the amount of sunspots on the Sun’s surface varies from a minimum to a maximum, and then back to a minimum

  • At the sunspot cycle’s minimum, there is reduced solar output.

  • At the sunspot cycle’s maximum, there is an enhanced solar output

What evidence does the sunspot theory stand on to say that it affects climate change?

Little Ice Age

Temps during a cold period plummeted further during sunspots minimum

Explain Volcanic Activity and how it can impact climate change?

• The ash and gas that is erupted into the atmosphere when there is a huge eruption can cause a cooling effect on the Earth’s climate.

• Volcanic Winter will happen

Volcanic eruptions can do this in two ways:

• Large amounts of volcanic ash can stay in the atmosphere and block out the sun. This is usually a short term cooling

• Volcanic eruptions can emit sulfurous gases which react to form aerosols which reflect solar radiation. This effect can last several.

What is a volcanic winter?

A volcanic winter refers to a period of global cooling caused by volcanic eruptions. When a large volcano erupts, it releases massive amounts of ash, gases, and aerosols into the atmosphere. These particles can block sunlight, leading to a decrease in temperature worldwide. The resulting cooling effect can last for months or even years, impacting climate patterns and potentially causing crop failures and other environmental disruptions.

What are some evidences that support the volcanic eruption and it’s impact on the climate change?

• 1783 - Laki, Iceland - The year after the eruption, Northern Hemisphere temps fell by about 1 degree Celsius, resulting is severe weather. 8000 addition deaths in the UK were recorded in the winter of 1783 - 1784. Severe weather continued for several years in Europe

• 1815 - Mount Tambora, Indonesia. The eruption caused global temperatures to fall by 0.4 - 0.7 degree Celsius, resulting in crop failures and famine. 1816 was commonly referred to as ‘The year without a summer‘

What is the Quaternary Period?

• This is when some major fluctuation in temperature have occured.

• The geological time period that started 2.6 million years ago and extends into the present.

• During this period, there have been many fluctuations between the colder glacial periods and warmer interglacial period.

What were some evidence for climate change from the past?

• Ice Core

• Tree rings

• Historical Sources

Explain Ice Cores and how they are past evidence for climate change

When snow falls on top of there ice sheet, it buries and traps older snow below. Over thousands of years, this snow builds up and compacts into thick ice.

Scientist drill down inside the sheets and extract large cylinders of ice called ice cores.

The can use the ice core to calculate:

• Changes in the temp

At the top of the core, this is the youngest ice but as they slowly go down it gradually becomes older.

The composition of water can be analysed to calculate what the temperature of the atmosphere was when that water fell as snow.

Air bubbles trapped in the ice can also be analysed: levels of CO2 and other gases can tell us more info about the climate at that time.

What was the furthest back in time an ice core has been able to go?

400,000 years

Explain tree rings and how they are past evidence for climate change

• They can be used to reconstruct the climate that those trees grew in.

• Each year, the trees gain another ring when it grows; if it is larger, it means the tree grew more that year.

• Scientist use the tree rings to work out when temperatures were more favourable for growth and therefore reconstruct past climate.

What will happen to tree rings if it is a dry season?

They will be thin

What will happen to tree rings if it is a rainy season?

They will be thick

Give some historical sources evidence to climate chnage?

• Photos, illustration and paintings can show what the past landscape was like. Painting during the ‘Little Ice Age‘ that depicts a cold climate, with lakes and seas frozen over.

• Records of animal behaviour/migrations or the dates that trees flower can indicate temp at the time.

• Books, journal and newspapers can be used to understand the climate, or date any weather events such as extremely cold winter.

What is the problem with Historical sources as evidence for climate change?

• It’s not accurate

• Not reliable

What are some human causes of climate change?

• The burning of fossil fuels during industrial processes, transport and energy production which has released greenhouse gases.

• Different farming methods, which release greenhouse gas

• Deforestation, which has reduced the CO2 taken up by trees, contributing to higher levels of greenhouse gases in the atmosphere.

What is the greenhouse effect?

A natural process where greenhouse gases (mainly carbon dioxide, methane, water vapour and nitrous oxides) trap the energy from the Sun inside the Earth’s atmosphere, which heats the Earth.

How is the greenhouse effect very similar to an actual greenhouse?

• The Greenhouse Effect is a natural process where greenhouse gases trap the energy from the Sun inside the Earth's atmosphere, which heats the Earth.

• In a greenhouse, the Sun shines through the glass, which heats up the air inside. This heat cannot escape as it is trapped by the glass, which keeps it warm inside.

What happens when the Sun shines on Earth?

• Solar radiation from the Sun (short-wave radiation) travels to our Earth and heats up the Earth's surface.

• The Earth gives off heat (long-wave radiation) when it cools.

• Some of this heat leaves our atmosphere and goes into space.

• Some of this heat is trapped by greenhouse gases, which keeps our Earth warm.

What is the enhanced Greenhouse Effect?

• Human activities release greenhouse gases into the atmosphere at a higher rate than natural processes

• As there are higher amounts of greenhouse gases in the atmosphere, more heat is trapped and cannot escape into space. This heat is reradiated around the Earth and cause the air to heat up more and more. This process has led to increased warming in recent years.

What are the main human activities that have made an increase in greenhouse gas levels?

• Fossil Fuels

• Agriculture - Rice Farming, Livestock

• Deforestation

How does fossil fuels make an increase in greenhouse gas levels?

• They are made up of the remains of organic material

• We burn fossil fuels for energy, which produces our electricity, fuels or cars and heats homes

• When fossil fuels are burnt, greenhouse gases are released such as carbon dioxide, nitrous oxide and methane. These greenhouse gases concentrate within the atmosphere, contributing to the enhanced greenhouse effect.

• The vast majority of CO2 comes from the burning of fossil fuels

How does agriculture make an increase in greenhouse gas levels?

• Agricultural activities produces a lot of methane. Methane is a more effective greenhouse gas than CO2, so it is better at trapping heat.

• About 25% of global warming is caused by methane but there is much less methane in the air that CO2

• Agricultural fertilisers also produce nitrous oxide, which can be up to 300 times more effective in capturing heat than carbon dioxide.

How does agriculture: rice farming make an increase in greenhouse gas levels?

In a paddy field, there are the right conditions to release a lot of methane. As rice is heavily cultivated across the world, rice farming is a large contributor to the levels of methane in the atmosphere.

How does agriculture: Live stock make an increase in greenhouse gas levels?

• Some farm animals, such as cows and sheep, produce methane when they digest food. One of these animals on average produces 250-500 litres of methane a day!

• Animals are kept all over the world as livestock to meet the population's demand for meat and animal products, which contributes to huge methane emissions.

How does deforestation make an increase in greenhouse gas levels?

• Trees take in CO2 from the atmosphere and store it inside them as carbon. Deforestation removes a large amount of trees which in turn reduces the amount of CO2 that is being taken in and stored, resulting in higher levels in the atmosphere.

• Burning wood releases CO2 that was stored in the trees and puts it in the atmosphere.

What are some evidences for human induced climate change?

• Sea levels Rise

• Decay of glaciers and ice

• Increased extreme weather

How is sea levels rising evidence for human induced climate change?

• Average global sea levels have risen by 21 - 24 cm since the 1800s and a third of this rise has occurred within the last 25 years.

• Sea level rise has been occurring because higher temperatures have caused glaciers and ice sheets to melt, and this freshwater then flows into the sea.

• Furthermore, thermal expansion happens so as the Earth warms, the whole sea is

  expanding and rising.

What is thermal expansion?

Thermal expansion is when the sea expands in response to changes in temperature.

How is decay of glaciers and ice evidence for human induced climate change?

• Glaciers and ice sheets are melting all around the world, which is evidence that the climate is warming.

• Some glaciers are projected to completely melt by 2035. The majority of glaciers are shrinking and thinning.

• Sea ice is also thinning and not extending as far, especially in the Arctic Ocean. Sea ice has thinned by up to 65% since 1975 in the Arctic Ocean.

How is increased extreme weather for human induced climate change?

• There has been an increase in extreme weather events, which is evidence that the climate is changing.

• Nine out of ten of the warmest years on record have occurred in the 21st century.

• Prolonged periods of hot, dry weather are becoming more common in parts of the world.

• Precipitation is also becoming more intense, increasing flooding risk.

• Tropical storms are becoming more intense, and forest fires are happening more frequently, which is thought to be because of the changing climate.

What are the effects on the environment of climate change?

• Melting ice sheets, glaciers and sea ice

• Damage to terrestrial ecosystem

• Extreme weather - such as droughts, flooding, tropical storms, wildfires

• Warmer temperatures

• More areas susceptible to diseases such as malaria

• Changes in ocean currents and weather pattern

• Rising sea levels

• Warming oceans

• Damage to marine ecosystems

What are the effects on people of climate change ?

• Coastal flooding, destroying homes and infrastructure

• Displaced populations and climate migrants as it is no longer safe to live in certain areas.

• Risk to water supplies due to increased droughts and changes in weather patterns

• Farmine, dehydration, hygiene related diseases

• Increased health issues, such as heat stress and skin cancer

• Food insecurity as crops fail due to climate change

• Damage to infrastructure and property

What is the Intergovernmental Panel on Climate Change?

The Intergovernmental Panel on Climate Change (IPCC) is a scientific body established by the United Nations (UN) and the World Meteorological Organization (WMO). Its purpose is to provide policymakers with objective and up-to-date information on climate change.

What are the different scenarios that The Intergovernmental Panel on Climate Change have created projection of temperature and sea level rise?

• The worst case scenarios - the most warming is RCP8.5 which is where global greenhouse gas emissions remain very high throughout the century

• The best case scenarios - the least warming is RCP2.6 which is where global emission are cut drmatically.

• RCP4.5 and RCP6.0 are intermediate scenarios

Define physical uncertainties?

Physical uncertainties refer to the limitations or errors associated with measurements and observations in the physical sciences.

What are some physical uncertainties about climate change that scientist have?

• As the climate warms, there is uncertainty about how natural processes may enhance warming. E.g. methane is being released by melting permafrost in the Arctic.

• Some sources of water that contribute to sea level rise are so variable they are difficult to account for when projecting future sea level rise (e.g. water in reservoirs).

• There is uncertainty about how weather phenomena may affect temperatures, such as the El Niño climate cycle.

• Cold meltwater from glaciers and ice caps will reduce the effect of thermal expansion, which therefore may influence sea level rise.

Define Human uncertainties?

Human uncertainties refer to the inherent unpredictability and variability in human behavior, decisions, and perceptions.

What are some human uncertainties about climate change that scientist have?

• We don't know how big the population will be in the future, so there is uncertainty over future energy and food demands.

• Lifestyles may change as more people become aware of climate change. .

• Future technologies may help to cut emissions.

• There is uncertainty over how much green energy we will use globally. We may shift to renewable energy such as wind and solar power, or we may continue to be reliant on greenhouse gas-producing fossil fuels.