Climate change

Question 1

Global average temperatures have increased by about…

Answer 1

1 degree Celsius (1.8 degrees Fahrenheit) since the late 19th century.

Question 2

The rate of warming has accelerated in recent decades…

Answer 2

the five warmest years on record all occurring since 2010.

Question 3

The oceans have absorbed much of this heat…

Answer 3

The top 700 meters (2,300 feet) of ocean warming by about 0.4 degrees Celsius (0.7 degrees Fahrenheit) since 1969.

Question 4

Arctic sea ice has decreased by…

Answer 4

about 13% per decade since 1979.

Question 5

Sea levels have risen by…

Answer 5

About 8 inches since 1880.

Question 6

Palaeoclimatic indicators

Answer 6

Ice cores
Palynology
Fossils
Foraminifera
Paintings / novels
Past weather records

Question 7

Ice cores; What they do, Pros / Cons.

Answer 7

Snow settles on the surface, oxygen and carbon from the atmosphere within the snow become compressed when a new layer forms, again and again until these layers are preserved in the ice sheet.

O18 and 016 oxygen isotopes can be examined; 018 evaporates from ocean at higher temperatures. Therefore if a core layer has more 018, it indicates a warmer year.

In addition, the amount of co2 present in the ice can indicate how warm the climate was in such period.

Pros:
Can be used to see past temperatures of up to 800,000 years ago in antarctica

Cons:
Can be difficult to distinguish the ice core layers when examining older samples, as the pressure causes regelation in the ice which distorts layers.
Also expensive to do.
May not be indicative of the global climate, and more just the area where they were drilled from.

Question 8

Micro fossils

Answer 8

By examining micro fossils found in ocean sediment samples, the climate at the time can be deduced through 2 ways:

O16 / O18 oxygen isotope ratio in the fossil
Type / species of fossil, as only certain species can survive in certain temperatures, due to foraminifera being highly sensitive to climatic changes.

Dated using radio carbon dating techniques; Oldest microfossils on Earth around 3.5 billion years old, however, less than 100 million years old to actually work out past temp.

Cons:
Very hard to identify if old due to breaking up over time
Can move location due to currents.

Question 9

Paintings / books / other media

Answer 9

Paintings / novels can be used to depict what past temperatures were like, such as Charles Dickens a Christmas carol which took place during the victorian era during the little ice age in the uk, which lasted approx from 1300 to 1850. This therefore shows how it can be used to indicate past temps, as there is vivid detail on how the thames used to freeze and people would ice skate / winter markets.

Cons:
Quantitative, can be bias / up to interpretation, not accurate

Question 10

Palynology

Answer 10

The amount of pollen found in sediment deposits, such as peats and bogs, can indicate past climates;

For example, they can show:
Type of species pollen was from, which indicates temp, as plants can only survive in certain temps
Also show the amount of pollen, as higher amounts of pollen found which are dated to a certain year indicate that it was a warmer year and more plants bloomed.

Cons:
Like micro-fossils, pollen samples can be moved around due to a variety of factors such as landslides, tectonic movement, washed away during rainfall etc. Also not as accurate as other proxies.

Question 11

Internal forcing mechanisms:

Answer 11

Tectonic plate movement / ocean currents changing
Volcanic eruptions
Greenhouse gases

Question 12

external forcing mechanisms

Answer 12

Milankovitch cycles
Sunspots

Question 13

How can tectonic plate movement cause climate change?

Answer 13

Creation on the Panama Isthmus about 3 million years ago had a profound impact on the Earth’s climate. The isthmus blocked the flow of water between the Pacific / Atlantic, forming the gulf stream, which is a warm ocean current that flows from the Gulf of Mexico up the Eastern coast of the US.

Before the isthmus, currents could flow between both oceans via the central american seaway, which cooled the climate. After this was blocked, the gulf stream warmed the earth by approx. 2/3*C

Question 14

How can volcanic erection cause climate change

Answer 14

The average temperature in the Northern Hemisphere was about 0.2 degrees Celsius cooler than average during the months following the eruption of Eyjafjallajokull.

Due to the increased albedo of the ash clouds.

Question 15

Eccentricity

Answer 15

Eccentricity: The Earth’s orbit around the Sun is not perfectly circular, but rather it is slightly elliptical. This means that the Earth’s distance from the Sun varies throughout the year. The eccentricity of the Earth’s orbit changes over time, with periods of high eccentricity (when the Earth’s orbit is more elliptical) and periods of low eccentricity (when the Earth’s orbit is more circular). The eccentricity of the Earth’s orbit has a cycle of about 100,000 years.

Question 16

Obliquity

Answer 16

Obliquity: The Earth’s axis is tilted relative to its orbital plane. This tilt is what causes the seasons. The Earth’s obliquity changes over time, with periods of high obliquity (when the Earth’s axis is more tilted) and periods of low obliquity (when the Earth’s axis is less tilted). The obliquity of the Earth’s axis has a cycle of about 41,000 years.

Question 17

Precession

Answer 17

Precession: The Earth’s axis precesses, or wobbles, like a spinning top. This precession is caused by the gravitational pull of the Sun and the Moon. The Earth’s precession has a cycle of about 26,000 years.

Question 18

Sunspots

Answer 18

Sunspots are areas of intense magnetic activity on the surface of the sun. Sunspots release higher amounts of solar radiation.

Cycle lasts around 11 years, with the peak and minimum of this short term cycle not effecting temp. significantly (0.1% of solar radiation variation)

However, over centuries sunspot activity can effect the global temperature to a higher effect; e.g. The maunder minimum which caused colder winters and lower global avg. temps from 1650-1720 due to less sunspot activity according to scientists.

Question 19

Reasons for the Anthropocene (anthropogenic climate change)

Answer 19

Population increases - increases in carbon footprints worldwide

Land use changes - forestry being cut down and used for farming, which increases methane + co2

Energy demand - due to globalisation + new technologies + population increase, more energy is required than before, resulting in the burning of coal / natural gases.

Question 20

GHG contribution case study countries

Answer 20

AC = UK
EDC = China

Question 21

AC GHG contribution statistics

Answer 21

The UK remained dependent on coal as its main energy source for much of the twentieth century. Although coal production peaked in 1916 (137 million tonnes), as late as 1961 output was still more than 120 million tonnes.

UK’s CO emissions peaked in 1971. Since then, annual emissions have fallen by around one-third.

There are several reasons for this:
The shift away from coal as the primary fuel to cheaper natural gas.

The development of nuclear power stations (particularly in the 1970s and 1980s) and renewable sources of energy since the 1990s.

Improvements in energy conservation through more energy-efficient homes, offices and factories.

International obligations and legally binding reductions in carbon emissions.

In 2014 alone, uk emissions fell by approx. 9%

80% reduction in co2 emissions by 2050

Question 22

EDC GHG contribution statistics

Answer 22

1990: China emitted 2.7 billion tons of carbon dioxide equivalent (CO2e).
2000: China emitted 4.3 billion tons of CO2e.
2010: China emitted 9.8 billion tons of CO2e.
2020: China emitted 14.5 billion tons of CO2e.

The government has pledged to peak emissions by 2030 and achieve net-zero emissions by 2060.

Question 23

Differing opinions on climate change

Answer 23

Media:
Some say media causes hysteria
Additionally, media can often find it hard to understand scientific research / methodology around CC
Such as Fox news etc

Lobbying:
Some parties have vested interest in keeping CC a conspiracy, such as energy companies, which donate to keep policy in their favour. For example, in 2019, the API spend $15 million on lobbying.

Question 24

Impacts of climate change

Answer 24

Ecosystems disrupted (marine / terrestrial)
Diseases spread
Extreme weather events
Food scarcity

Question 25

How does climate change impact ecosystems

Answer 25

Marine:
Coral bleaching; When ocean temps. rise above a certain level, the coral’s algae dies, which causes bleaching. This effects levels of marine life as coral reefs help sustain biodiversity. Up to 80% of corals bleached in Seychelles and Maldives, although corals can bounce back from this with the help of coral nurseries.

This will cause the death and depopulation of fish species that rely on coral, such as the clownfish.

Terrestrial:
Ice caps melting resulting in the loss of hunting ground for polar bears, which have driven them to search of a different habitat, such as Wrangel island in Russia.

Additionally in forest biomes fires have increased, and according to the IPCC the frequency of forest fires has doubled over the past 20 years.

Question 26

Diseases spread by climate change

Answer 26

Mosquito numbers increase + migrate to increase in malaria.

This is due to the fact that mosquitos require warmer temperatures to survive in

Additionally, increased rainfall and floods have caused more breeding, as they need water to lay their eggs in.

This has caused increases in mosquito population, in addition to how mosquitos can not migrate to areas in which they were not previously able to do so due to the colder climate.

Question 27

Water vapour in our atmosphere has increased by…

Answer 27

4% since pre-industrial levels

Question 28

Floods have increased in frequency by…

Answer 28

20% since 1960’s

Question 29

Food security negatively effected by global warming

Answer 29

Droughts, due to the 1*c rise in global average temps. since pre-industrial era, have caused decreases in crop yields worldwide.

This causes low food security, due to subsidence farming in many poor nations

Additionally, floods have increased in frequency by 20% since 1960.

Both mean that the price of food has increased.

811 million currently starving, expected to double by 2050 if climate change continues as it is.

Question 30

Ways of reducing GHG in our atmosphere (mitigation)

Answer 30

Switching to Green energy production
Reducing our carbon footprint
CCS
Afforestation
Geo-engineering

Question 31

Switching to Green energy production (mitigation)

Answer 31

Coal and natural gas production to decrease.
Instead, sustainable, green energy sources to increase instead.
I.e. Solar, wind, hydroelectricity

Pros:
Carbon zero
Renewable, will never run out

Cons:
Expensive to build
Doesn’t generate as much electricity

Question 32

Reducing our carbon footprint (mitigation)

Answer 32

Improving vehicular fuel efficiency + type of fuel
Encouraging uses of public transport
Insulating homes
Improving energy efficiency in coal / oil plants

Pros:
Less co2 output from the general population
Also increases awareness of GW from public

Cons:
Hydrogen fuel cells can be bad for environment / unsustainable according to critics, instead, further advancements in biofuel / hydrogen fuel cells needs to be done.

All these may be costly for the government to subsidise, e.g. public transport / insulate homes (UK govt. can’t afford to insulate all homes, but can still pass new legislation to increase regulations)

Question 33

Afforestation (mitigation)

Answer 33

Afforestation can remove up to 2.1 billion tonnes of CO2 from the atmosphere per year by 2050. This is equivalent to about 5% of the world’s current annual emissions.

Also increases biodiversity + reduces flooding

Cons:
May cause an increase in wildfires initially, but if done at a large scale will reduce temps massively.

Question 34

Geo-engineering (mitigation)

Answer 34

Artificial volcanoes:
Releasing ash / sulfur into the atmosphere to create albedo; E15 caused -0.2*c change in global temps. in NH in the months following the eruption.
Hugely impractical, increasing ash / sulfur in atmosphere would pollute air.

Iron fertilisation:
Encourages the biological pump; Phytoplankton absorbing co2 from the atmosphere and fixing it into the biosphere / lithosphere. However, we don’t know the unintended consequences of adding iron to the oceans

Space mirrors:
Big ass mirrors in space that reflect solar radiation away from Earth. Proposed to be the size of Brazil. Cost 5 trillion et. (obvious cons).

GM crops:
Crops with increased Suberin photosynthesise at a higher rate which increases carbon sequestration, as they store more carbon in roots and therefore need more co2; They also grow thicker waxy cuticles which increase albedo.

Additionally, this is adaption, as they can be bred to be more resistant to temperature changes and therefore increase food security (e.g golden rice).

Painting cities white:
Cities such as Mykonos have increased albedo due to white paint, cooling city

Question 35

Adaptation strategies

Answer 35

Retreating to more suitable areas to live in
Accommodation
Protecting

Question 36

Retreating to more suitable areas to live in (adaption)

Answer 36

Managed realignment, relocating buildings and agriculture, and creating new habitats
Abandoning low-lying coastal locations altogether
Zoning vulnerable floodplains location to prevent building there

Question 37

Accomodate

Answer 37

Agriculture:
GM crops, zero tillage (increases soil moisture retention, preventing floods)
Sustainable water supply and use of grey-water in agriculture

Question 38

Protect

Answer 38

Hard engineering:
flood defences to reduce impact of sea level rise (8 inches since p.-i.t.)
Dam construction, which is also mitigation
Increasing AC to reduce heatstroke
Painting buildings white, geo-engineering (also mitigation)
Mashrabiya latticework, causing increased ventilation.

Soft engineering:
Restoring wetlands, which is also mitigation
Reducing standing water to reduce mosquito breeding

Question 39

CS for climate change impacts

Answer 39

AC - Australia
LIDC - Bangladesh

Question 40

Australia: geography, climate change impact

Answer 40

Geography:

Tropical rainforest in NE, subtropical rain forests mid-E coast, broadleaf rain forest in SE + Island of Tasmania

Great Artesian Basin- largest groundwater source in the world
758 estuaries

22,258 mil coastline

Impact:

Natural disasters cost Australia US$4.5 billion/year
Most of population, major cities and infrastructure is on the coast, high risk from coastal flooding

Cyclone Yasi in 2011 reduced Queensland’s GDP by US$4 billion

Great Barrier Reef along the country’s east coast has been damaged by ocean acidification

Question 41

Bangladesh

Answer 41

Geography:

On average, 70% of the country floods every year

Bay of Bengal lies in the south, low lying.

10% of country just 1 m above sea level

Humid, warm climate with frequent monsoons

Impact:

Tropical cyclones cost $1 billion annually for Bangladesh

Cyclones (past 25 years, 60% of global deaths from tropical cyclones have been in Bangladesh)

Flooding (10% of country just 1 m above sea level)

According to the NASA Earth Observatory, roughly 70 million people in Bangladesh now live in flood-prone areas (within 2 kilometers of a river)

Question 42

Timeline of climate agreements

Answer 42

1997: The Kyoto Protocol is adopted at COP3 in Kyoto, Japan. The Kyoto Protocol is an addition to the UNFCCC that sets legally binding targets for industrialised countries to reduce their greenhouse gas emissions.

2005: The Kyoto Protocol enters into force.

2015: COP21 is held in Paris, France. The Paris Agreement is a legally binding agreement that sets out a long-term goal of limiting global warming to well below 2 degrees Celsius, preferably to 1.5 degrees Celsius, above pre-industrial levels.

The European Union has set a target of reducing its greenhouse gas emissions by 55% by 2030.

Question 43

Climate agreements - Pros

Answer 43

Give an over-arching aim for all countries (e.g. limit to below 2*C since pre-industrial levels)

Can be used to form binding legislation in countries

Can be used as an event to inform the public on the dangers of climate change

Question 44

Climate agreements - Cons

Answer 44

Unfair - LIDC countries are being asked to sacrifice more than other countries. This can lead to resentment and lack of co-operation.

Not legally binding - Countries can leave agreements when they want. For example, in 2020, when Trump left the Paris climate accords, however, Biden rejoined on his first day in office in Jan 2021.

Question 45

Emission trading scheme - what it is, pros / cons

Answer 45

EUETS (EU Emissions trading scheme)

Caps the amount of co2 emissions that factories can produce by allocating pollution permits to firms, which are dependent on the size of the producer. The amount allocated decreases year on year, and those that pollute more than their allocation are fined.

Permits can be traded, which creates another incentive for firms to lower their co2 emissions, as they can make a profit from selling their permits to other corporations. Most of the profit made is then spent on “going green”.

Pros:
Everything above;
EUETS covers approx. 45% of all GHG produced in the EU.
They have so far achieved a 20% reduction in co2 emissions from 1990-2020

Cons:
Not stringent enough; the fines can work out not so expensive for firms which ignore the scheme in order to keep producing.
Doesn’t cover all sectors
Isn’t ambitious enough
Is too complex for many producers to comply with

Question 46

California policies to combat climate change

Answer 46

Mitigation:

Reducing reliance on fossil fuels. The state has set a goal of getting 50% of its electricity from renewable sources by 2030.

Cap and trade system (second largest worldwide after EUETS) covering 85% of carbon polluters in the state.

15% of green energy cars by 2020

Adaptation:
Building seawalls
Implementing drought resistant GM crops
Increasing water security - California has a water scarcity problem which is exacerbated by droughts.

Question 47

Wildfires ipcc statistc

Answer 47

20% increase per decade since 1970