Outline two factors that affect the frequency and severity of photochemical smog in an area.

Evaluate strategies to manage regional acid deposition using the pollution management model.

To what extent have international agreements been successful in solving atmospheric air pollution and climate change?

societies with intensive fossil fuel use/industrialization;
...produce more of the primary pollutants;

high population density is characterized by car traffic/more dense use of heating;
...which increases the concentration of the primary pollutant;

local climate can have thermal inversions/lack of wind;
...that traps the smog/decreases its dispersion;

local climate with intense sunlight;
...increases photochemical reactions/increases rate of production of secondary pollutant;

topographic factors such as hills and mountains;
...can result in trapping the pollutants/reducing wind dispersion;

Notes: Award [1] max for clearly identifying each factor, and [1] max for outlining its effect on severity/ of smog:
Award [1] max if factors are simply identified by their title with no explanation eg “population density” and “topography”
Any of the points above can be equally credited if presented in the form of a case study eg Los Angeles / Mexico City, etc).

Altering human activity:
changing transportation use to reduce private transportation / increase public transportation / walking/biking;
this can be expensive due to infrastructure improvements required;
requires public buy-in / change in behaviour;
successful if a reduction in use of fossil fuels for transportation needs;
successful if good network of charging stations / footpaths/bike lanes to encourage change;
addresses root cause of pollution/prevents any damage in first place;

education of public regarding value of renewable energies/impacts of pollution;
this can influence more environmentally friendly choices;
influences attitudes/values in future generations;
but maybe the local governments/authorities that need influencing more than general public;

Controlling release of pollutant:
reduce sulphur content of fossil fuels using trading system or pollution budgets;
has proved very successful in USA where government put legislation in place to support this;
increases costs as low sulphur fuels are more expensive / requires technological investment;

use catalytic converters on car exhausts/scrubbers/CATS;
very effective at reducing nitrous oxides;
...but expensive;
use heavy metals which need to be mined;
catalysts need replacing frequently;
effective but requires investment in the technology and expensive;

switch to renewable energy sources/nuclear;
very effective as no direct emissions of NO_x or SO_x;
requires diversification of energy supply, which requires political will;
requires investment to support the change in energy policy;
successful when implemented with supportive legislation;

increase efficiency of power production and demand;
advantage that it reduces all pollutants associated with power production;

taxation systems and trading mechanisms;
very effective when implemented with political support;
requires improvement in public transportation infrastructure;
could be argued that not ethical as encourages trading of pollutants;

international legislation to control emissions (eg Sulphur Emissions Reduction Protocol and the Convention on Long Range Transboundary Air Pollution);
have been successful in reducing sulphur dioxide emissions;
...but led to increase in nitrous oxide production;
can be difficult to implement and monitor;

Clean-up and restoration of damaged systems:
adding limestone powder to acidified lakes;
effective and cheap solution;
but does not remove the cause of the problem;
environmental impact of mining the limestone;

restocking lakes after remediation;
needs careful management and unlikely to return the lake to the prior system;

reafforestation/replanting of damaged forests;
expensive;
takes long time for restoration;
new growth acts as effect carbon sink;

Note: Award [5] max if only one or two out of three levels of the pollution management model addressed.
Award [3] max if no evaluation points given.

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 of international agreements (Montreal Protocol, Kyoto Protocol/Paris Agreement/UNCED/UNFCCC, Convention on LRTRAP, UNEP, UNECE, Agenda 21) in different environmental issues; climate change; air pollution; acid deposition; ozone depletion; solid domestic waste; resource depletion; population growth; energy choices;
• breadth in addressing and linking a wide range of international agreements with various solutions(laws/regulations/strategies/actions/projects) to issues of different forms of atmospheric pollution and climate change
• examples of international agreements; solutions to the problems requiring international agreements;
• balanced analysis discussing successful and less successful international agreements showing understanding of the factors involved in the amount of success;
• a conclusion that is consistent with, and supported by, analysis and examples given eg currently the Montreal Protocol is thought to be the most successful international piece of legislation tackling an environmental problem. The problem of ozone depletion was not challenged in the political sphere and there were solutions that industry could implement. It did not require any change to the way that people lived their lives. Climate change legislation, on the other hand has been politically controversial and despite all countries initially signing up to the Paris Accord in 2015, it is still struggling to be implemented as it requires system-wide changes to the way countries organise themselves;

Many candidates responded well to this question having clear and specific details relating to photochemical smog.

Most candidates had a sound grasp of the issue of acid deposition and even some strategies for addressing it. However, a large proportion of candidates simply described the strategies rather than "evaluating" them.

Responses were generally good to very good, often addressing at least three different examples of international agreements and evaluating their effectiveness with some insight.