Environmental Science Fundamentals Flashcards

Which biogeochemical cycle is most directly disrupted by the combustion of fossil fuels?

Answer: Carbon cycle

Fossil fuel combustion releases carbon stored underground back into the atmosphere, directly disrupting the natural carbon cycle.

What term describes the ability of Earth's surface and atmosphere to absorb and re-emit thermal radiation?

Answer: Greenhouse effect

The greenhouse effect is the process by which greenhouse gases trap heat in the lower atmosphere by absorbing and re-emitting infrared radiation.

Which ocean process absorbs approximately 25-30% of anthropogenic CO₂ emissions annually?

Answer: Air-sea gas exchange

Air-sea gas exchange (physical solubility pump) drives CO₂ dissolution from the atmosphere into ocean surface waters, accounting for roughly 25-30% of annual anthropogenic CO₂ uptake.

In the context of climate science, what does 'radiative forcing' measure?

Answer: The change in energy flux caused by a climate driver

Radiative forcing measures the change in energy flux (W/m²) in the atmosphere caused by natural or anthropogenic factors, indicating whether the climate will warm or cool.

Which of the following best describes a carbon 'sink'?

Answer: A reservoir that absorbs more carbon than it releases

A carbon sink is any reservoir — such as forests, soils, or oceans — that absorbs and stores more carbon from the atmosphere than it releases.

What is the primary driver of ocean acidification?

Answer: Absorption of atmospheric CO₂ forming carbonic acid

When seawater absorbs CO₂, it reacts with water to form carbonic acid (H₂CO₃), which dissociates and lowers ocean pH, causing acidification.

Which layer of the atmosphere contains the ozone layer that protects Earth from UV radiation?

Answer: Stratosphere

The ozone layer is located in the stratosphere, approximately 15–35 km above Earth's surface, where it absorbs harmful ultraviolet radiation.