6.2 Climate Change - Causes & Impacts

6.2.1 Climate describes the typical conditions that result from physical processes in the atmosphere.

Climate vs Weather

6.2.2 Anthropogenic carbon dioxide emissions have caused concentrations of atmospheric carbon dioxide to rise significantly. The global rate of emission has accelerated, particularly since 1950.

What percentage of total anthropogenic CO₂ emissions have been released since you were born?

6.2.3 Analysis of ice cores, tree rings and deposited sediments provide data that indicates a positive correlation between the concentration of carbon dioxide in the atmosphere and global temperatures.

Write the text of a short children's book to explain one or more source of evidence for global warming.

6.2.4 The greenhouse effect has been enhanced by anthropogenic emissions of GHGs. This has led to global warming and, therefore, climate change.

6.2.5 Climate change impacts ecosystems at a variety of scales, from local to global and affects the resilience of ecosystems and leads to biome shifts.

6.2.6 Climate change has an impact on (human) societies at a variety of scales and socio-economic conditions. This impacts the resilience of societies.

Project Brief - CAS - St. Johns School - Emma, Reet, Purab, & Harry (1).pdf

Complete the table below. Do one entire case study and then move to the next.

Impacts of Climate Change

Climate change: London is underprepared for extreme weatherThe capital is at risk from rising sea levels, flooding, heat, drought and wildfires, a report says.

What will climate change look like in your area? - BBC NewsThe BBC and the Met Office have looked at the country's changing climate in detail.

A Summary of Climate Change Risks for London.pdf

Golden Toads: Facts & Why They Went Extinct | IFAWLearn all about the extinct golden toad, including its delicate ecosystem and how climate change had a significant impact on its declining population.

6.2.7 Systems diagrams and models can be used to represent cause and effect of climate change with feedback loops, either positive or negative, and changes in the global energy balance.

Draw a suitable diagram for each of the following feedback loops. Check your answer against a published ESS source (Save My Exams, InThinking, etc.)

Solar radiation variation

Terrestrial albedo changes

Methane gas release

6.2.8 Evidence suggests that the Earth has already passed the planetary boundary for climate change.

"According to the Science Advances publication in 2023 the planetary boundary for climate change is set at 350 ppm CO₂ in the atmosphere and and for radiative forcing* at 1 W m⁻². In 2022, the estimated total anthropogenic effective radiative forcing was 2.91 W m⁻² and atmospheric CO2 concentration was 417 ppm. This puts us well beyond one degree of warming and heading above 1.5 degrees of warming with extreme Earth system impacts."

Quoted from InThinking

* Radiative forcing (RF) is a scientific measure of the imbalance between the energy entering Earth’s atmosphere from the sun and the energy leaving it as infrared radiation. Forcing is positive when more energy is received than radiated back to space. This extra energy heats the planet.

6.2.9 Perspectives on climate change for both individuals and societies are influenced by many factors.

Draw a systems diagram of your own environmental value system around climate change. Consider inputs to the system (i.e. influences) and outputs (e.g. actions, beliefs)

Repeat this exercise for a public figure.

HL ONLY

6.2.11 Global climate models manipulate inputs to climate systems to predict possible outputs or outcomes using equations to represent the processes and interactions that drive the Earth’s climate. The validity of the models can be tested via a process known as hindcasting.

Same Information, Different Format

A defence of GCMs

Climate Model HindcastingAn interactive look at climate models published since 1972, comparing their predictions to observed global temperatures to see how well they did.

Try hindcasting out for yourself. Which models were the best?

6.2.12 Climate models use different scenarios to predict possible impacts of climate change.

RCPs.pdf

Play around with the Climate Atlas. Can you find something surprising?

6.2.13 Climate models show the Earth may approach a critical threshold with changes to a new equilibrium. Local systems also have thresholds or tipping points.

Planet’s first catastrophic climate tipping point reached, report says, with coral reefs facing ‘widespread dieback’Unless global heating is reduced to 1.2C ‘as fast as possible’, warm water coral reefs will not remain ‘at any meaningful scale’, a report by 160 scientists from 23 countries warns

Amazon rainforest could reach ‘tipping point’ by 2050, scientists warn‘We need to respond now,’ says author of study that says crucial forest has already passed safe boundary and needs restoration

6.2.14 Individual tipping points of the climate system may interact to create tipping cascades.

Source

6.2.15 Countries vary in their responsibility for climate change and also in vulnerability, with the least responsible often being the most vulnerable. There are political and economic implication and issues of equity.

With reference to the figures above, to what extent are concepts of tragedy of the commons and polluter pays principle relevant to global environmental justice?

Extension Resources

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