Lecture 11 Flashcards
The Anthropocene
hothouse-icehouse cycles
the alternation between hot and cold periods (i.e. ice ages) of Earth
neolithic revolution
the emergence of agriculture, domestication of plants/animals, and shift in human settlement patterns
the impact of early humans on Megafauna
hunting pressure led to the decrease of Megafauna
what the UNFCCC stands for
the United Nations Framework Convention on Climate Change
the biggest reason for modern extinctions
habitat damage (i.e. fragmentation, destruction, and degradation)
Over the past ________ years, atmospheric CO2 have fluctuated alongside global average ________.
200,000 years, temperatures
pros and cons of nuclear fission vs. nuclear fusion technology
- nuclear fission is well-tested, but produces more radioactive waste
- nuclear fusion is currently being developed, but produces much less radioactive waste
ecological release
a huge increase in population due to a lack of limiting factors (density-dependent growth to exponential growth)
ocean acidification
as CO2 concentrations increase, the pH of the ocean decreases (CO2 is stored as an acid in water)
the first species to be endangered due to global warning
polar bears
When a species experiences ecological release, it becomes an…
invasive species
the greenhouse effect
- Solar radiation passes through the atmosphere; some is absorbed, but some is reemitted as heat.
- Some heat (longwave radiation) emitted from Earth escapes to space, but some is absorbed by CO2 molecules and remitted in all directions, capturing heat and increasing Earth’s temperature.
- Human activities that release other greenhouse gases (e.g. N2O and methane) increase the retention of heat within the atmosphere.
an example of a species that is benefitting from human activity
coyotes: humans are creating more acceptable habitat and removing competitors (wolves)
why the Earth is currently hottest than it’s ever been
it’s not, we are currently in an ice age
four possible solutions to mitigate climate change
- solar energy
- wind energy
- biofuel and hybrid cars
- nuclear power
direct and indirect causes of climate change
direct causes
- changes in CO2 levels
- changes in sea level (melting/formation of ice sheets)
indirect causes
- asteroid impacts
- volcanic eruptions
anthropocene
the interval of time where human activities dominate key processes on Earth, and impact biodiversity on a global scale
the four industrial revolutions
- The Industrial Revolution (18th century): textile manufacturing, gas lighting, steam engines
- The Technological (2nd Industrial) Revolution (early 19th century): electricity, factories, cars, telephones
- The 3rd Industrial Revolution (late 20th century): computers and the Internet
- The 4th Industrial Revolution (early 21st century): Big Data, AI, hyperconnectivity
Those who contribute the ________ greenhouse gases will be most impacted by climate change.
least (e.g. tropical regions)
seven major threats to biodiversity
- habitat fragmentation (segragating parts of the habitat)
- habitat destruction (e.g. building a mall in a forest’s place)
- habitat degradation (including pollution)
- invasive species
- pathogens
- climate change
- overexploitation of resources
how humans travelled from Africa
during ice ages, sea levels were lower; allowing for travel where is now normally not possible
two key treaties of the UNFCCC
- the Kyoto Protocol (1997)
- the Paris Agreement (2015)
What is troubling about the increase in Earth’s temperature?
it’s not necessarily the increase in Earth’s temperature, but the speed at which Earth’s temperature is increasing
the UNFCCC’s goals
- ultimate goal: to stabilize greenhouse gas concentration in the atmosphere at a level that avoids anthropogenic interference with the climate system
- other goals: nature conservation, food security, poverty reduction
the “ice feedback loop”
- as ice builds, sunlight is reflected, leading to more ice
- as ice melts, sunlight is absorbed, leading to less ice
how tree lines have shifted
northward and upslope
We are at the start of a ________ event.
mass extinction
four major greenhouse gases
- water vapour (H2O)
- carbon dioxide (CO2)
- nitrous oxide (N2O)
- methane (CH4)
