HS-ESS3-4: Improving a Design That Reduces Human Impact
Also called NGSS HS-ESS3-4 · Topic: Human Sustainability · Earth and Space Science
The Official Wording
Evaluate or refine a technological solution that reduces impacts of human activities on natural systems.
Clarification statement: Examples of data on the impacts of human activities could include the quantities and types of pollutants released, changes to biomass and species diversity, or areal changes in land surface use (such as for urban development, agriculture and livestock, or surface mining). Examples for limiting future impacts could range from local efforts (such as reducing, reusing, and recycling resources) to large-scale geoengineering design solutions (such as altering global temperatures by making large changes to the atmosphere or ocean).
NGSS Lead States, 2013 · Read it on nextgenscience.org · checked October 15, 2026
What HS-ESS3-4 Means in Plain English
Students take a technology meant to lessen people's harm to nature, such as a green roof, a stormwater filter or a recycling program, and judge how well it works using data. Then they suggest and test changes that make it work better.
Evidence can include amounts of pollution released, changes in the number of species, or how much land is paved or farmed. Solutions range from local projects to proposals that would alter the whole planet. It builds on HS-ESS3-2 and uses HS-ETS1-3.
HS-ESS3-4 I Can Statements
- I can measure how well a design reduces an environmental impact.
- I can suggest one change to improve a design and test it.
- I can weigh an improvement against its new costs or limits.
HS-ESS3-4 Worked Example
A green roof test a class can run with planting trays, a watering can and a measuring jug.
How much storm runoff does a model green roof hold back, and can the design be improved?
Set It Up: Three plastic planting trays with drain holes, one bare, one with 3 cm of potting soil and sedum cuttings, one with 6 cm, plus a watering can, a tub and a measuring jug.
- Tilt each tray slightly over the tub and pour 1 liter of water evenly over it, like a heavy storm.Same storm for every roof
- Measure the water that drains off in 10 minutes.Bare 950 mL, 3 cm 600 mL, 6 cm 400 mL
- Work out the share of the storm each roof held back.5%, 40% and 60% retained
- Weigh each tray when soaked, since a real roof must carry the load.6 cm tray much heavier
- Refine: swap in a lighter mix with perlite at the same 6 cm depth and retest.Similar retention, lighter tray
Deeper soil held back more of the storm, and a lighter mix at the same depth kept that gain with less weight on the roof.
Why it works: Soil pores and plant roots store water and release it slowly, which cuts the surge of runoff that carries pollutants from roofs into streams.
Common Mistakes with HS-ESS3-4
Judging by looks
“The plants look healthy, so the roof works.”
Try this: Pick a measurable target, like the share of storm water held back, and compare it to an untreated control roof.
Ignoring new costs
Recommending 30 cm of soil on every roof
Try this: Check each improvement against its constraints, such as weight, cost and upkeep, because a better result can create a new problem.
Changing everything at once
A deeper, lighter, newly planted tray tested once
Try this: Change one feature per trial and repeat each test, so you know which change caused the improvement.
Where HS-ESS3-4 Fits
Practice HS-ESS3-4
Quick Check
- A bare tray shed 950 mL of a 1,000 mL storm and a green roof tray shed 600 mL. What share did the green roof hold back?
- Why do cities care about slowing runoff, not just the total amount?
- Deeper soil worked better. Why not make it as deep as possible?