ACARA v9 CONTENT DESCRIPTION “examine how proposed scientific responses to contemporary issues may impact on society and explore ethical, environmental, social and economic considerations”
Builds on knowing that materials such as plastics have useful properties but cause problems as waste. Here we move from the science to the decisions: every proposed response to a real issue brings benefits and costs that society has to weigh.
Science offers responses, but each has a price
Plastic is cheap, light and long lasting, which makes it useful but also makes plastic waste a hard problem. Plastic that escapes into rivers and oceans can last for centuries and harm wildlife. Science can suggest several responses, yet none of them is free of downsides. Choosing between them means weighing the effects on the environment, on people, on fairness and on cost. That weighing, not the science alone, is how communities decide what to do.
Responses to plastic waste: what is gained, what is given up
Pick a proposed response to plastic waste and see the benefit it brings and the cost it carries. There is no option with only upsides.
A town is flooded with single-use plastic and wants to cut the waste. Several scientific responses are on the table. Choose one to see its main benefit and its main cost.
Choose a response to see what is gained and what is given up.
Four kinds of effect to weigh
Scientists and decision makers usually look at four kinds of effect together. Environmental effects ask what happens to land, water and wildlife. Social effects ask how daily life and fairness change for different people. Ethical effects ask what is the right thing to do, for example toward future generations. Economic effects ask about cost, jobs and money. A response that looks great on one of these can score badly on another, which is why a town often uses several responses at once rather than betting on a single fix.
Testing a popular claim
People often say that recycling on its own will solve the plastic problem, so there is no need to make or use less. Scientists who study waste reach a more careful conclusion: recycling helps, but cannot do the job by itself. Sort the statements below into those that are real evidence for that conclusion, and those that sound related but do not actually test it.
Is recycling alone enough to fix plastic waste?
The claim is that recycling helps but cannot solve the problem on its own. Decide which statements genuinely support it.
Claim: Recycling reduces plastic waste but cannot solve it alone, so using less plastic still matters.
Worldwide, only a small fraction of all the plastic ever made has actually been recycled.
Most plastics can be melted and remade only a few times before the material becomes too weak to reuse.
Food-stained or mixed plastics are usually rejected at the sorting plant and sent to landfill.
Recycling bins come in bright, cheerful colours that people like.
Plastic floats, so a dropped bottle is easy to see in a river.
Decide whether each statement is evidence for the claim, or not.
What the data from a real scheme shows
Decisions like these are judged by data gathered afterwards. Several Australian states brought in a container-deposit scheme, paying a small refund for each drink container returned. To see whether it worked, scientists counted drink containers among the litter on beaches and roadsides each year. Read the figures below, as containers found per survey, as a table and then as a graph. The drop after the scheme began, in year 3, is the evidence decision makers were looking for.
Drink containers found in litter surveys, before and after a deposit scheme
The scheme started in year 3. Switch between the table, bar chart and line to see the change clearly.
Container litter falls sharply once the refund begins and keeps dropping. Counting before and after is how a community tells whether a scientific response actually delivers, rather than guessing.
Why this matters
From plastic waste to clean water to energy, you will meet many issues where science offers options but cannot, by itself, choose for you. Learning to lay out the benefits and costs, and to weigh environmental, social, ethical and economic effects together, is exactly how informed citizens and governments make decisions. Good choices come from honest trade-offs, not from pretending a perfect answer exists.
Quick self-check
1. Why is there no single perfect response to plastic waste?
2. Banning single-use plastic bags reduces litter, but a possible downside is that...
3. A cost of recycling that is often overlooked is that...
4. When weighing a scientific response, "economic considerations" means looking at...
5. What is the best overall lesson about scientific responses to big issues?