Energy
This renewable energy source powers nearly 20% of the world's electricity and has been criticized for displacing communities and disrupting river ecosystems.
What is hydropower (hydroelectric energy)?
This gas, which makes up about 78% of Earth's atmosphere, is not considered a greenhouse gas.
What is Atmospheric Nitrogen (N₂)?
In older cities like New York, rainwater and sewage share the same underground pipes — and during heavy storms, this is what happens when the system becomes overwhelmed.
What is a combined sewer overflow (CSO)?
This borough has about 25% of its land protected as green space.
The Bronx
Farmers add fertilizer primarily because this element, despite being abundant in the atmosphere, is not readily available for plants to absorb directly.
Nitrogen
Though solar and wind power produce no emissions during operation, these two factors represent their biggest shared drawback.
What are intermittency and energy storage challenges? (can accept variants)
If you removed this natural atmospheric phenomenon, Earth would become significantly cooler.
What is the greenhouse effect?
This upstate New York system, completed in 1842, was NYC's first major water supply — a 41-mile stone aqueduct bringing water from this river valley.
What is the Croton watershed / Old Croton Aqueduct?
This animal kept Dr. Rae Wynn Grant from leaving her tent.
A lion
This is caused by an excess of nitrogen and phosphorous, which trigger explosive algae growth in lakes and coastal waters.
Eutrophication
Solar panels require significant amounts of these materials during manufacturing, meaning renewable energy still has an environmental footprint before a single watt is generated.
What are rare earth metals?
These microscopic ocean organisms play a key role in reducing atmospheric carbon levels.
What are phytoplankton?
NYC adds this compound to water to prevent it from corroding lead pipes and releasing lead into tap water.
What is orthophosphoric acid (or phosphate)?
NYC's harbor is home to these large marine mammals that return each winter to feed on fish.
Humpback whales / dolphins
When an algal bloom dies and decomposes, bacteria consume so much dissolved oxygen that fish and other organisms suffocate — this condition is called what?
What is hypoxia (or a dead zone)?
Wind farms have faced opposition from local communities due to this concern, particularly when proposed near coastlines or scenic landscapes
What are visual impact (or: viewshed disruption) and/or hazards to birds and aircraft?
This natural and human-caused event releases stored carbon directly into the atmosphere.
What are forest fires?
This body of water once served as a drinking water source for Lower Manhattan's inhabitants before it became so polluted that it was filled in.
The Collect Pond
Species, genetic, and ecosystem diversity are all components of this broad ecological concept.
What is biological diversity (biodiversity)?
This nutrient is often the 'limiting nutrient' in freshwater systems — meaning adding it produces the greatest algae growth response.
What is phosphorus?
Renewable energy development in rural areas has provided this economic benefit to landowners.
What are land lease payments? (can also accept tax deductions)
Wetlands and permafrost are important carbon stores, but warming can cause permafrost to thaw and release large amounts of this potent greenhouse gas.
What is methane (CH₄)?
This approach saved the city millions of dollars by avoiding having to build a filtration plant for its Catskill/Delaware supply.
Protected the watershed through payments for ecosystem services (e.g. payments to farmers)
Though gray wolves have long been absent from New York City, this adaptable canid has stepped into the role of apex predator in NYC's parks and green spaces.
What is the eastern coyote?
This process, invented in the early 20th century, artificially fixes atmospheric nitrogen to produce ammonia, a key ingredient in synthetic fertilizers.
The Haber-Bosch process