Environmental Science Cheat Sheet 2026

The 30 highest-yield Environmental Science facts, distilled from real exam questions. Print it, save it as a PDF, or study it here — free, no sign-up.

1. What is carbon capture and storage (CCS)? → Capturing CO₂ at emission sources and injecting it underground
2. What is soil erosion's most significant agricultural impact? → Loss of nutrient-rich topsoil reducing crop productivity
3. Which term describes a species native and restricted to a particular geographic area? → Endemic
4. Geothermal energy is most economically viable in regions: → Located close to tectonic plate boundaries or volcanic hot spots
5. Which class of air pollutants is regulated under the U.S. Clean Air Act as the six common air pollutants? → Criteria air pollutants
6. What is water stress, as defined in environmental science? → When freshwater demand exceeds available supply
7. Tar sands (oil sands) require more energy to process than conventional oil primarily because: → The bitumen must be separated from sand and upgraded, requiring large energy inputs
8. The U.S. Clean Water Act regulates water pollution primarily through: → A permit system (NPDES) controlling discharges from point sources to navigable waters
9. What is the main environmental problem associated with CFCs (chlorofluorocarbons)? → Stratospheric ozone depletion
10. Which U.S. law provides the primary legal framework for protecting threatened and endangered species and their habitats? → Endangered Species Act (ESA)
11. Which type of symbiosis benefits one organism while the other is neither harmed nor helped? → Commensalism
12. Terracing as an agricultural technique on steep slopes primarily serves to: → Create level planting areas that reduce runoff velocity and soil erosion
13. Which water treatment process uses chlorine or UV light to kill pathogenic organisms? → Disinfection
14. Which region of the United States is most frequently referred to as 'Tornado Alley' due to the high frequency of tornado formation? → The Great Plains states from Texas to South Dakota
15. What is a carbon sink? → A natural or artificial reservoir that absorbs more carbon than it releases
16. During a hurricane, which component is responsible for the greatest loss of life along coastlines? → Storm surge flooding
17. What is an invasive species? → A non-native species that spreads rapidly and harms native ecosystems
18. What does NEPA (National Environmental Policy Act) require for major federal actions? → Preparation of an Environmental Impact Statement (EIS)
19. Which heavy metal is most commonly associated with contamination from old lead paint and pipes in U.S. homes? → Lead
20. What is the primary mechanism by which volcanic eruptions can cause short-term global cooling? → Sulfur dioxide emissions form sulfate aerosols in the stratosphere that reflect sunlight
21. Which contaminant, naturally occurring in some well water, has been linked to cancer and is regulated by the Safe Drinking Water Act? → Arsenic
22. Which concept describes the minimum viable population (MVP) in conservation? → The smallest population size with a high probability of persisting long-term
23. Which greenhouse gas has the highest global warming potential (GWP) over a 100-year timeframe among those listed? → Sulfur hexafluoride (SF6)
24. What is the global warming potential (GWP) of methane compared to CO₂ over a 100-year timeframe? → About 28–36 times greater
25. In terms of water use efficiency, which of the following irrigation methods uses water most efficiently? → Drip (micro) irrigation
26. Which type of solid waste site is designed with liners and leachate collection systems to prevent groundwater contamination? → Sanitary landfill
27. Nuclear fission reactors generate electricity by: → Splitting heavy atomic nuclei to release heat
28. Which soil texture has the highest water-holding capacity? → Clay soil
29. Which type of drought is defined by a deficiency of precipitation over an extended period? → Meteorological drought
30. What does the Dust Bowl of the 1930s illustrate about land management? → The effects of poor soil conservation practices on agriculture