Human Impacts Flashcards
(27 cards)
Which planetary boundaries are currently exceeded?
Climate change, biodiversity loss, fertilizer pollution, freshwater change, novel entities in the environment, land use change
Defined by the Stockholm Resilience Center.
Since when has it been known that the release of CO2 from fossil fuel burning can cause the climate to warm?
Since the 1800s (Fourier & Arrhenius, 1824, 1896)
Early scientific understanding of climate change.
How does CO2 and other greenhouse gases contribute to the greenhouse effect?
CO2 traps heat in Earth’s atmosphere by absorbing and re-emitting radiation, warming the surface.
Since when has the world community held conferences to discuss how catastrophic climate change can be averted?
1970 (Earth Day and onwards).
What was the first legally binding international agreement to reduce greenhouse gas emissions?
Kyoto Protocol, 1997.
What was the stated goal of the Kyoto Protocol?
Reduce GHG emissions by 5% below 1990 levels (2008-2012).
Did the Kyoto Protocol achieve its emissions goal?
No, it had limitations like excluding countries and lacking enforcement.
What is the stated goal of the most recent international climate change agreement?
Limit global temperature rise to 1.5°C above pre-industrial levels; called the Paris Agreement.
Is the USA a signatory to the Paris Agreement?
Yes (signed under Obama, rejoined under Biden).
What is the best-case prediction for global warming by 2100?
+1.5°C.
What is the worst-case prediction for global warming by 2100?
+6°C.
What is the best-case prediction for global sea level rise by 2100?
0.3–2.5 meters.
What is the worst-case prediction for global sea level rise by 2100?
0.3–2.5 meters.
How do positive feedbacks in the Earth System affect global climate?
Positive feedbacks amplify warming.
How do negative feedbacks in the Earth System affect global climate?
Negative feedbacks moderate warming.
Give an example of a negative feedback.
Increased carbon sequestration by oceans and land.
Give three examples of positive feedback.
- Melting permafrost releases greenhouse gases
- Increased forest fires
- Enhanced water vapor due to warming.
What human populations are most at risk from sea level rise?
Near coastal areas.
What is the anticipated effect of global warming on vegetation distribution?
Biomes will shift; greening at northern edges, browning at southern edges.
Why have scientists called the present the ‘Sixth Mass Extinction Event’?
Current extinction rates are 1000–10,000 times higher than the natural rate.
What are the main known causes of species extinctions?
- Climate change
- Habitat destruction
- Pollution.
How are dead zones in the Gulf of Mexico linked to corn and soybean production?
Runoff from corn and soybean fields carries nitrogen, leading to algal blooms and hypoxia.
What perils do migratory birds face due to global warming?
Disruption of breeding/migration timing.
What causes habitat loss for migratory birds?
Land use change.
