Paper 2: global climate

Geography IB paper 2: global climate SL/HL

What is the cause of the natural greenhouse effect?

What is the cause of the natural greenhouse effect?

Incoming short-wave solar radiation is absorbed by the earth and long wave radiation is re-emitted by the earth. The long wave radiation is reflected by greenhouse gasses like carbon dioxide and methane in the earth’s atmosphere.

Insolation

Incoming solar radiation

How is energy from the equator redistributed to the poles?

Wind and air circulation, ocean circulation

What are the two reasons that insolation is less intense at higher latitudes?

• Because the concentration of sunlight is lower because it is spread over a wider area

• Because the sunlight passes through more atmosphere before it reaches the ground

What is the formula for calculating albedo value?

(Intensity of radiation reflected from surface/ amount of incident radiation) x 100 = albedo value (%)

Factors that can change albedo value

• Land-use change

• Smoke

• Pollution

• Windblown dust

• Loss of ice

What three natural factors can change the Earth’s climate?

Cycle of sunspot activity, volcanic activity, the Earth’s changing orbit

How does the Earth’s changing orbit affect global temperature and climate?

The Earth’s orbit changes from circular to elliptical about once every 100,000 years

Cycle of sunspot activity

• There is an 11-year cycle of sunspot activity

• Sunspots send out flares of solar radiation including UV rays and X-rays

• More sunspots means the Earth receives more radiation

• ‘Solar minimum‘ is when there are fewest sunspots

Volcanic activity

The expulsion of material from volcanoes can heat or cool the Earth depending on the substance.

• Sulfur dioxide can cool the Earth by reflecting incoming solar radiation (as per mount Pinatubo eruption, 1991)

• Carbon dioxide and other ghgs can warm the atmosphere

What was the Maunder minimum?

• Aka the “little ice age“

• A period in the late c17th where Europe experienced extremely harsh winters due to a prolonged period of very low solar activity

• After this there was a gradual increase in sun activity over 300 years

What is blocking in terms of global climate?

• A meteorological phenomenon that affects the dynamics of jet streams (very strong winds 7-12km above the Earth’s surface)

• There is one jet stream in each hemisphere and they majorly influence weather systems

• A blocking event occurs when the jet stream forms an S-shape over the North-Eastern Atlantic

• Could also be responsible for Maunder Minimum

• Can be modulated by solar activity

What is the case study for pollution?

Linfen in China

Linfen, China

-20 years ago called the “fruit and flower town“, now named the most polluted city in the world by the World Bank

-One day breathing its air is equivalent to smoking three packs of cigarettes

-Called a “cancer village“ because of the higher incidence of diseases like stomach and lung cancer

-Water pollution from factories and mines

Pollution in China, stats

-Over half of Chinese rivers and a third of Chinese lakes are polluted

-70% of Chinese cities cannot meet the air quality standards

-16 of the world’s 20 most polluted places are in China

Named example of reshoring

Trunki

Definition of reshoring

The reverse of offshoring: a business returns its production to the host company having been offshore previously

Crowdsourcing

The process of sourcing ideas, services, finances and information from the public on the internet to benefit from a large group of people

Aerosol

A colloidal suspension of particles dispersed in air or gas

Named example of a volcanic eruption leading to global dimming

Pinatubo, 1991

Pinatubo eruption, 1991

• 17 megatons of sulfur dioxide entered the stratosphere

• Changed weather systems and cooled the atmosphere measurably for almost 2 years

• Parts of the Northern hemisphere experienced cooler summers while other places experienced milder winters

How can atmospheric pollutants actually mitigate global warming in the short term?

In air polluted by aerosols, water is spread out over more particles leading to increased surface area which causes more sunlight to be reflected

What evidence is there that vapour trails from planes could be mitigating global warming?

After 9/11, when all planes were grounded, the diurnal temperature range decreased by 1 degree C, sparking debates as to whether vapour trails could be causing global warming in the short term

Carbon sequestration

The process of capturing and storing carbon dioxide (CO2) from the atmosphere or other sources. This can be an artificial process of CCS or through the natural carbon cycle.

Atlantic Meridional Overturning Circulation

Draws greenhouse gasses and heat straight into the oceans, helping alleviate early impacts of carbon emissions

What is REDD?

A strategy to reduce the rate of deforestation. To get money for forest protection by placing a monetary value on the forests and then selling forest carbon credits on a carbon market

Named example of drought

In San Paulo Brazil there was the worst drought in 80 years

How do trees reduce drought?

Rainforests import rain, transpire (releasing their own moisture) and lower the atmospheric temperature

Named example of flooding

In Germany scientists concluded that the flood that happened was made 9x more likely because of climate change

Effects of 1 degree C increase in global temperature

• Arctic sea ice will disappear during the summer months

• Most of the world’s coral reefs including the GBR will die

• Climate related diseases such as malaria and diarrhea will affect 300,000 people/year

Effects of 2 degree C increase in global temperature

• The Southern UK will regularly sea summer highs of 40 degrees C

• 1/3 of the world’s species will become extinct

• The Amazon rainforest will become dessert and grassland

Effects of 4 degree C increase in global temperature

• Arctic ice cover would permanently disappear

• Permafrost would release methane and CO2 currently locked in soil

• Many island nations would be submerged by a 5m rise in sea level

• Much of Europe (Italy, Spain, Turkey and Greece) would become desert

Positive impacts of global climate change for the UK

• Potential increased opportunity for recreation and tourism with higher summer temperatures and reduced precipitation in the south

• Pastoral farming in the North-West could improve

• Up to 25% increase in timber yields in the North by 2050

Negative impacts of global climate change for the UK

• Increased probability of floods, droughts and storm surges

• Rising sea levels

Describe an example of the effects of global climate change/water shortage on an HIC

• California, USA

• Hotel owners’ water bills doubled because of the drought

• Changing irrigation methods/restricted times of water

• Price of many foods increasing

• Water no longer served in restaurants except by explicit request

• Better surfing conditions

Describe an example of the effects of global climate change/water shortage on an MIC

• Water crisis in Brazil

• No water in some communities’ pipes for a month

• Reservoirs have reached rock bottoms

• Deforestations in Amazon means fewer trees to ‘import’ rain

• Open sewers → polluted rivers

Describe an example of the effects of global climate change/water shortage on an LIC

• Desertification in Burkina Faso

• Land is less fertile

• Chronic food insecurity due to poor crop yields

• Harvests from rain-fed agriculture could decline by 50%

What changes in biomes can be predicted due to climate change?

• Upwards altitudinal shift in biomes as most regions become hotter

• More desert cover and melting of ice in polar/tundra regions

• Organisms unable to migrate or adapt will become extinct

Give two examples of species that have shown physical/genetic adaptations to climate change

• Tawny owls have changed from being majority-white to majority-brown as the recessive allele for white feathers declines due to less snow

• Two-spot ladybirds: now exist almost exclusively in their non-melanic form so that they don’t overheat

Examples of species movement

• The range of the British comma butterfly has shifted 137 miles North in two decades

• Migratory birds are arriving in the UK earlier

Examples of species’ behavioural change

• Dormice come out of hibernation 8 days earlier each decade

• Breeding and flowering seasons change

What is the importance of soil?

• Used to grow crops (carbon-rich soils increase crop yields)

• Store massive amounts of carbon (3x as much carbon as trees)

• Carbon-rich soils act as sponges protecting the earth from floods and droughts

Causes of soil erosion

• Population growth: more demand for food

• Industrial agriculture and monocrop practices

• Deforestation (plant cover and their roots protect the soil)

Effects of soil erosion

• In the USA soil loss is 17x faster than the normal rate

• Nutrient loss from soils requires harmful fertilisers and pesticides to be injected into the soil

How can atmospheric carbon be transferred back into the soil?

• Keeping soil covered in plants

• Composting

• keeping animal grazing to a minimum

What are the three main factors associated with vulnerability to climate change?

• Exposure

• Sensitivity (potential to be harmed)

• Adaptive capacity (whether they could mitigate the effects)

Give some examples of mitigation strategies for climate change

• Carbon tax

• CCS

• International agreements

• Aforestation

• Investment in renewable energies

Give some examples of adaptation strategies for climate change

• Building houses on stilts to protect from flooding

What is carbon offsetting?

• A way of compensating for daily emissions such as driving through getting companies to plant trees or an equivalent service

• Critics say there is an insufficient monitoring of these schemes

What is the example of a global treaty on climate change?

• The 2015 Paris agreement (COP21)

• Aims to limit global temperature increase to 1.5 degrees C max

• Addresses adaptation to climate change, financial and other support to developing countries, losses and damage

Strengths of COP21 (the Paris agreement, 2015)

• 195 countries agreed

• Potential to end dangerous climate change

• Justice for LICs affected by HICs’ GHG emissions in the past

• Frequent account regarding emissions targets

• Legally binding

Weaknesses of COP21 (the Paris agreement, 2015)

• Requires massive (unrealistic) GHG reductions by 2050

• Climate change is a low priority for some countries

• Requires massive investment and innovation in renewables

• Merely a ‘statement of interest‘

What is the EU’s emissions trading system?

• Countries and companies are given a tradable emissions allowance

• 1 credit=1 tonne of CO2 or equivalent

• Polluters who exceed their credits must buy more or incur fines from the EU

• The number of credits issued decreases year on year

What is the proposed sunlight reflection method of mitigating climate change?

Some scientists have suggested injecting sulfur dioxide directly into the stratosphere to mimic the cooling effect of the mt Pinatubo eruption 1991

Potential strengths of the sunlight reflection method of mitigating climate change

• Could buy time to cover transition to renewables

• Could work as a last resort

• Sulfur dioxide has been proven to have a cooling effect (though the side effects are unknown)

Potential weaknesses of the sunlight reflection method of mitigating climate change

• May distract countries from transitioning to renewables

• Unsustainable, requires millions of tonnes of sulfur dioxide to be released annually

• Controversy has limited possible research

• Could make holes in the ozone layer

• Could cause 50 years’ worth of warming in a decade

What is the role of NGOs in controlling global warming?

• Put pressure on companies and governments to reduce their carbon emissions

• Call upon governments to sign international agreements to preserve forests, conserve resources, reduce fossil fuel dependence etc

• Encourage individuals to make changes

Give an example of how an NGO is helping to reduce carbon emissions

The World Wildlife Fund (WWF) set up the ‘one-in-five challenge‘ encouraging companies to cut 20% of their business flights within 5 years.

This is achievable by videoconferencing technology and promotion of rail travel.

Companies that meet the target receive the NGO’s formal recognition and a specially-designed panda logo.

Give an example of how a company or TNC is reducing carbon emissions

ExxonMobil, which denied climate change in the 1970s, now expresses support for a carbon tax and the Paris Agreement. ExxonMobil now reduces greenhouse gas emissions in its own operations, encourages consumers to reduce theirs, and supports research.

What are fluxes with reference to the global carbon cycle?

Processes that transfer carbon between stores

What are pools with reference to the global carbon cycle?

Places where carbon is stored

What is meant by geoengineering?

The deliberate large-scale manipulation of an environmental process that affects the earth's climate, in an attempt to counteract the effects of global warming

Give two examples of geoengineering strategies.

Injecting sulfur particles into the stratosphere, delivering millions of small mirrors into space.