Lesson 3: Climate change Flashcards
What does anthropogenic climate change mean?
Climate change caused by human activities
What two gases have the biggest impact on the greenhouse effect?
Carbon dioxide (CO₂) and water vapor.
Why is too much methane problematic?
Methane oxidizes in the atmosphere, producing CO₂ and water, both of which contribute to the greenhouse effect.
How do greenhouse gases cause global warming?
Shortwave radiation from the sun passes through the atmosphere and is absorbed by the Earth. The Earth emits longwave (infrared) radiation, which is trapped by greenhouse gases, re-emitting heat back to the surface and causing global warming.
What other factors could cause an increase in global temperature?
Sunspots, variations in Earth’s orbit, and volcanic activity.
What are some consequences of global warming?
Extreme weather events, rising sea levels, invasive species
How are rising CO₂ levels affecting coral reefs?
CO₂ dissolves in water, forming carbonic acid, which lowers ocean pH (acidification). This reduces calcium carbonate availability, weakening coral skeletons and making reefs less resilient.
What impacts does melting ice have on polar bears?
Longer swimming distances, loss of hunting grounds, habitat fragmentation, and reduced genetic diversity due to isolated populations.
What is the positive feedback cycle of global warming in terms of sea ice?
Rising temperatures melt ice, reducing albedo (reflectivity). Darker surfaces absorb more heat, accelerating warming and further ice melt.
What is peat?
Partially decayed organic matter that accumulates in waterlogged, acidic conditions.
Why is peat important?
It sequesters carbon, reduces flood risk, and naturally filters water.
What is the positive feedback cycle of global warming in terms of peat?
Rising temperatures increase microbial activity, accelerating peat decomposition and releasing CO₂ and methane, which further increase temperatures.
What are three approaches to increasing carbon sequestration?
Afforestation, restoration of peat-forming wetlands, and forest regeneration.
Q: What is afforestation?
A: Planting trees in areas where there were no forests.
Q: What is forest regeneration?
A: Allowing forests to regrow naturally without human intervention.
Q: What are some pros of afforestation?
A: Fast carbon sequestration, biodiversity benefits, and economic opportunities like timber production.
Q: What are some cons of afforestation?
A: Conflicts with agriculture and urban development, high costs, and potential competition with local species.
Q: What are some pros of forest regeneration?
A: Cost-effective, promotes local species, and requires minimal human intervention.
Q: What are some cons of forest regeneration?
A: It takes time, and rules must be implemented to prevent disturbance during regrowth.
Q: What are some pros of restoring peat-forming wetlands?
A: Reduces flooding, restores biodiversity, and enhances carbon sequestration.
Q: What are some cons of restoring peat-forming wetlands?
A: Slow sequestration rates, high costs, and requires significant resources.
Q: What impacts does climate change have on ocean currents and upwelling?
A: Rising temperatures and melting ice alter water density and salinity, disrupting ocean circulation and reducing nutrient-rich upwelling.
Q: What is upwelling?
A: The process by which deep, cold, nutrient-rich water rises to the ocean surface.
Q: What is phenology?
A: The study of the timing of biological events, such as migration, flowering, and egg-laying.
