d4.3

These flashcards cover key concepts of anthropogenic climate change, its impacts, and biological responses to changing environmental conditions.

What do greenhouse gases (GHGs) do in Earth’s atmosphere?

They trap heat, maintaining the Earth's temperature essential for life.

Name the major greenhouse gases.

CO₂ (carbon dioxide), CH₄ (methane), N₂O (nitrous oxide), and H₂O (water vapour).

How have human activities impacted levels of greenhouse gases?

They have increased CO₂, CH₄, and N₂O levels, enhancing the greenhouse effect.

What is a positive feedback cycle in the context of global warming?

It is a feedback loop that intensifies global warming by amplifying warming effects.

Give an example of a positive feedback cycle related to CO₂ outgassing.

Warmer temperatures reduce CO₂ solubility in oceans, causing more CO₂ to escape into the atmosphere.

What is a tipping point in climate change?

A critical threshold where small disturbances cause irreversible changes.

How do boreal forests act as a carbon sink?

They absorb CO₂ through photosynthesis and store carbon in trees and soil.

What happens to boreal forests when a tipping point is reached due to climate change?

They shift from being carbon sinks to carbon sources, releasing more CO₂.

What effect does melting ice have on polar ecosystems?

It disrupts polar ecosystems and threatens species, such as Emperor Penguins and Walruses.

What is the significance of ocean currents in climate change?

They are driven by wind and temperature changes, which when altered by climate change can affect nutrient distribution.

What is phenology in the context of climate change?

The study of the timing of biological events and their relationship to seasonal and environmental factors.

How does climate change disrupt the synchrony of phenological events?

It alters environmental cues, causing mismatches in life cycles, such as plant blooming and animal migrations.

What impact do rising temperatures have on insect life cycles?

They accelerate life cycles, leading to more generations and potential overpopulation of insect species.

How can evolution be a consequence of climate change?

Climate change creates selective pressures, leading to genetic adaptations in organisms.

Give an example of how tawny owls are evolving due to climate change.

Rising temperatures reduce snow cover, causing brown owls to become more common as they are better camouflaged in non-snowy areas.