Exercises: Consequences and sustainable habits

Name three consequences of climate change and briefly explain one of them.

Order the three Rs — recycle, reduce, and reuse — according to their environmental priority and give an everyday example of each.

What is carbon footprint? Name two actions from your daily life that would reduce it.

Explain two causes of sea level rise (the melting of ice caps and glaciers, and the thermal expansion of water as it warms) and one consequence for coastal areas and islands.

The "One Health" approach links human health, animal health, and ecosystem health. Explain this using an example, such as the spread of disease-carrying mosquitoes due to rising temperatures.

Your middle school wants to become more sustainable. Propose three specific measures (one regarding energy, one regarding transportation, and one regarding waste) and justify each one.

The graph shows the average daily direct $\text{CO}_2$ emissions per student according to the means of transport used to travel to school.

1. a) A secondary school with 300 students who currently travel alone by private car is considering two emission-reduction measures for a school year of 180 school days:

• Option 1: Create a municipal school bus route that manages to attract 60% of those students.

• Option 2: Build a secure bicycle parking facility that gets 30% to cycle and another 20% to carpool (at a rate of 4 students per vehicle, dividing car emissions by 4).

Quantitatively calculate the total $\text{CO}_2$ savings (in kg) that would be obtained with each option and justify which one is more effective.

1. b) A classmate claims that the graph proves that cycling has zero environmental impact (0 kg of $\text{CO}_2$) under any circumstance. Refute this statement by distinguishing between direct emissions during use and indirect emissions throughout its entire life cycle.

In Mexico, heat waves and droughts are becoming increasingly frequent. Explain two effects of this trend on ecosystems (wildfires, water stress…) and propose two adaptation measures.

In the municipal plenary session of a town of 4 000 inhabitants, the budget to install community composters and pedestrian lanes is being debated. A councilor argues: "Our emissions are 0.001 % of those of the region; if large metropolises do not act, whatever we do here is a waste of money that will not alter the global climate."

1. a) Refute the councilor's stance by applying the motto "Think globally, act locally", using the concepts of ecological co-responsibility and multiplier effect.
2. b) Describe in detail the biological or physical mechanism by which collecting and composting organic waste instead of depositing it in a conventional landfill prevents the emission of a potent greenhouse gas into the atmosphere.