Rate
It is not the magnitude of the current warming that is dangerous for life, it is the _____.
rate
Although extinction 'triggers' have changed throughout Earth history (volcanos, impacts, humans, etc.), the direct causes for extinctions is always the same; that is: _______ ________ ________
Rapid Climate Change
(would also accept: rapid perturbation to the C cycle)
When extinctions occur within ecosystems, this often disrupts the entire food chain, causing cascading extinctions.
We, humans, sometimes think of ourselves as separate from this process. This is one example of a mindset called _________ ______________.
Human Exceptionalism
Name two ways individuals can combat climate change in their daily lives?
Many answers: less plastic use, drive less or more public transit, recycling, donating/contributing to or volunteering for carbon sequestration projects, volunteering for climate policy-related projects/groups, science communiction, & VOTING.
Climate change is not the only cause.
Other human activities are contributing which are changing Earth in ways it has never experienced before.
_____ % of terrestrial & marine species surveyed globally have shifted to higher latitudes &/or elevations.
~50%
The 3 most harmful effects of rapidly increasing greenhouse gases in the atmosphere include (1) ________ _________, (2) ________ _____________, and (3) _________ _________
global warming, ocean acidificaiton, & ocean anoxia
What are two ways we can combat the Urban Heat Island (UHI) effect?
White roofs, more vegetation, better infrastructure (more air circulation allowed).
The current rate of extinctions is about ______ times the background rate.
The only other times extinction rates have been this high were during the _____ _____ mass extinctions.
2. 'Big 5'
In order, name the Big 5 mass extinctions that came before this one.
Ordovician, Devonian, Permian, Triassic, & KPg.
Data suggests that without conservation efforts, mammal, bird, & amphibian extinction rates would be ____% higher.
So yay! Conservation does something! But we need more conservation efforts focused on _____________.
1. ~20%
2. invertebrates (things like algea, corals- ecosystem sustaining species)
Averaged globally, ocean circulation has slowed by about _____ %.
~30%
One concept we have continued to highlight in climate solutions (which combats desertification, wildfires, & cascading extinctions, and increases ecosystem health & resiliency) is _________.
DIVERSITY
It's estimated that a 5°C warming at a rate of 10°C per million yrs would cause an extinction event on par w/the 'Big 5'.
What rate (per million yrs) are we currently warming Earth?
17,000 deg C / million years
(1) What triggered the Ordovician and Devonian mass extinction events & (2) how can we apply this to combating modern climate change & the 6th mass extinction?
1. Spread of land plants caused rapid increase in continental weathering & soil formation which rapidly pulled carbon out of the atmosphere, causing global coolng.
2. We can induce weathering & soil formation to combat modern global warming!
Although climate change has been the focus of this class ________ _________ is currently the biggest threat to species on Earth.
Habitat destruction
Ocean acidification has such significant effects on life because it causes extinctions of key species in ecosystems (like reef-builders & base of the food chain organisms like primary producers). Thus, when these go extinct, other species will go extinct; this is called: __________ __________
Cascading extinctions.
What are three ways we can lower atmospheric carbon concentrations?
Induced continental weathering projects
Planting trees
Regenerative agriculture
Ocean fertilization
Which past extinction event (of the Big 5) was the most rapid? About how long did it last?
How long will ours last if we continue warming Earth at our current rate?
The KPg (asteroid impact trigger) - lasted about 1 million years.
At current rate of warming, it would only take about 300 years to cause an event on par with the Big 5.
Given that we are experiencing both rapid global warming and desertification, which past mass extinction event is the best analogue for ours? Why?
End-Permian event (great dying).
Because it was caused by both rapid global warming (due to volcanism) and desertification (due to Pangea), causing similar changes to those we see today.
Name 5 ways (other than burning fossil fuels) that humans are impacting the planet.
Pastics (and other pollution)
Desertification
Deforestation
Habitat destruction / Habitat fragmentation
Overuse of resources
Invasive species
Poor forest management (more intense wildfires)
We have actually seen evidence of this spreading in Earth's past, during the _________ _________, when oceans became so anoxic that this chemical even spread to the shallow parts of the ocean, killing many reef ecosystems!
1. H2S (hydrogen sulfide)
2. Permian Extinction (or Great Dying)
Why are carbon sequestration projects better in the long-run for combating modern global warming than albedo-increasing projects?
In other words, why should we focus more on removing carbon from the atmosphere than reflecting sunlight to cool Earth?
Because this event has been caused by our removal of carbon from the geosphere, we need to put it back there to balance things out. Carbon sequestration will do this, but increasing albedo will not.