Outline the albedo effect and its role in regulating the Earth’s global temperature.

Compare and contrast the adaptation strategies to climate change for two societies.

Discuss whether biodiversity loss or climate change is a greater threat to human societies.

1. albedo is a measure of the reflectiveness of a surface / is greater from lighter-coloured/smoother surfaces;
2. high albedo means that solar radiation is reflected away from a surface/reducing temperature / low albedo means that solar radiation is absorbed by a surface/increasing temperature;
3. oceans/ice/clouds contribute significantly to Earth’s albedo;
4. the balance between the albedo of the Earth’s surfaces involves feedback loops;
5. negative feedback loops reduce change (retain the balance in ratio of albedo) and maintain the global temperature;
6. e.g. rise of global temperature $\to$ increased evaporation $\to$ increased cloud cover $\to$ increased albedo and reflection of solar radiation $\to$ decrease in global temperature;
7. a change in the balance can result in a positive feedback loop which amplifies changes and results in a rise in the Earth’s global temperature;
8. e.g. rise in global temperature $\to$ increase melting in ice caps $\to$ decrease in albedo $\to$ increase in solar radiation absorption $\to$ rise in global temperature;

Note: Accept alternative feedback loops.

The following adaptation strategies can be credited provided it is clear whether they are common to both societies (compare) or are a point of difference (contrast).

weather readiness…

1. flood defences;
2. increase resilience of ecosystems, e.g. flood retention in mangroves/marshes;
3. support water saving/reduction schemes (for droughts);
4. planting of crops in previously unsuitable climates;
5. tree plantings, shady areas, reflective construction materials, green roofs, and the ecological management of rainwater;
6. produce plans for heatwaves;
7. develop rapid response teams;
   
   health…
8. vaccination programmes;
9. reduce water and air borne diseases;
   
   education…
10. include climate change in educational curriculum;
11. provide information to citizens about risks;
12. capture indigenous knowledge for benefit of all;
13. invest/support scientific research into climate change monitoring and adaptation;
    
    infrastructure and economy…
14. desalinization plants;
15. diversification away from climate sensitive industries;
16. increase resilience of communities through economic development;
17. increased resilience of buildings and infrastructure (to heat waves, flooding);
18. legislation and planning to consider climate impacts;
19. monitoring, forecasting and early alert systems;

Notes: Award [5 max] if only compare or only contrast used.
Award [3 max] if strategies are simply described but not clearly compared or contrasted between two named societies.

Refer to paper 2 markbands, available under “your tests”  tab > supplemental materials

The following guide for using the markbands suggests certain features that may be offered in responses. The five headings coincide with the criteria given in each of the markbands (although “ESS terminology” has been conflated with “Understanding concepts”). This guide simply provides some possible inclusions and should not be seen as requisite or comprehensive. It outlines the kind of elements to look for when deciding on the appropriate markband and the specific mark within that band.

Answers may include:

• understanding concepts and terminology biodiversity (habitat, species, genetic); climate change; threats to ecosystems from biodiversity loss; threats to ecosystems from climate change; impact of these on human societies; threats to food production from both; extinction; hotspots; sustainable development goals;
• breadth in addressing and linking tipping points; positive and negative feedback loops; regime shifts/alternative stable states; possible use of solutions to address challenges of each threat (mitigation, adaptation, conservation strategies); benefits of biodiversity; ecosystem resilience; ecosystem stability; biome shift; loss of keystone species; conservation, EVSs; uncertainty of GCC impacts/modelling;
• examples of scale of biodiversity loss; impacts to food webs/productivity/ecosystems; examples of climate change impacts on ecosystems/society/economics/energy production (at both global and local scale); examples of causes of biodiversity loss and of climate change;
• balanced analysis two-way (bidirectional) interaction of climate change and biodiversity loss; contrast efficiency/difficulty of conservation/management strategies to mitigation/adaptation strategies (in the context of different EVSs); political implications (national & international agreements, role of NGOs); compare present rate and scale to past events; contrast local to global scale;
• a conclusion that is consistent with, and supported by, analysis and examples given e.g. I believe climate change is a bigger threat to human societies as it will result in biodiversity loss in more systems than areas which could gain in biodiversity and result in multiple impacts on human health, human populations from severe weather, however without building ecosystem resilience through preserving biodiversity, climate change will be even more of a threat to human societies;

Most candidates had some valid idea of albedo and its role in temperature regulation.

A large proportion of candidates mistook mitigation strategies for adaptation and so failed to gain significant credit.

Generally well answered, although weaker candidates failed to explore the full scope of the question.