Finding Solutions to Human-made Acid Rain (6-8th Grade NGSS)

Acid Rain is created when large industrial facilities (e.g. Midwestern utilities) burns coal or oil which gives off sulfur, nitrogen, and carbon into the air. Their smokestacks carry these waste gas emissions into the clouds where they mix with water vapor to form weak acids – sulfuric, nitric, and carbonic acids. The wind patterns of North America carry pollutants from busy cities, factories and industrial centers in the Midwest for hundreds of miles east to the Northeastern U.S. and Canada. When the moisture in the clouds grows heavy enough, it falls as rain - acid rain (or snow). When acid rain falls into lakes and streams, it can make the water so acidic that fish and frog eggs won’t hatch. It corrodes limestone buildings, walkways, and statues. Acid rain can slow the growth of trees. It leaches calcium out of conifer needles which makes them more susceptible to winter damage. It also leaches the calcium and magnesium from the soil. Calcium and magnesium are important for the health of the forest because these components are “base cations.” They act as natural buffers in the soil, keeping it from being too acidic. Once they are depleted, the aluminum in the soil dissolves and can be absorbed by trees and plants and acts as a toxin that damages them. In sugar maples, the damage starts to show up as a die off in the top of the crown of the tree. The first sign of acid rain damage to a hardwood forest is when maple crowns start to change color in the fall earlier than the rest of the tree. The forests and communities of the northeastern U.S. and Canada have been the victim of acid rain that started as air pollution from Midwestern utilities for the last 100 years.

Though changes in ecosystems are normal and natural over time, humans can cause significant changes that can be devastating and long lasting. Coming up with possible solutions to counter these negative effects is an important exercise. In this performance task, students will come up with solutions to the problem of acid rain pollution on Northeastern North America.
Goals: Students will do research, come up with potential solutions, build models, and evaluate them for their effectiveness.
Procedures:
1. Discuss the problem. What causes acid rain? How is it human made?
2. Also discuss what makes a solution practical. For instance, we can suggest that Midwestern companies just stop burning coal, so the pollution stops, but this is not a practical solution.
3. Their solutions should try to meet the criteria (what they want), but also address the constraints (the needs of the solution) of the problem.
4. They should start by researching the problem.
5. Then brainstorm as many potential solutions as they can.
6. Then do some model building - this can be drawings of possible solution designs.
7. The next step is testing, which will not be easy to do in the scope of this activity, but should be discussed. They can also research how certain solutions have worked in real life and discuss how to improve them.

Problem: Acid Rain is created when large industrial facilities in the Midwest burns coal or oil which gives off sulfur, nitrogen, and carbon into the air. Their smokestacks carry these waste gas emissions into the clouds where they mix with water vapor to form weak acids – sulfuric, nitric, and carbonic acids. Then wind patterns carry the pollutants to the Northeastern U.S. and Canada where it falls as acid rain damaging the ecosystems of forests and waterways.

MS-LS2-4. Construct an argument supported by empirical evidence that changes to physical or biological components of an ecosystem affect populations. [Clarification Statement: emphasis is on recognizing patterns in data and making warranted inferences about changes in populations, and on evaluating empirical evidence supporting arguments about changes to ecosystems.]

ETS1.B: Developing Possible Solutions - There are systematic processes for evaluating solutions with respect to how well they meet the criteria and constraints of a problem. (secondary to MS-LS2-5)