Week 8 - Future Climates Flashcards
What are the Milankovich Cycles?
Changes in Earth’s orbit around the sun.
What are the three basic types of Milankovich Cycles?
Eccentricity, tilt of the rotation axis, and procession of the equinoxes.
What is eccentricity?
Changes in the elliptical nature of Earth’s orbit around the Sun. High eccentricity means more elliptical, low eccentricity means more circular.
What do the Milankovich Cycles explain?
Glacial and inter-glacial periods.
What does tilt of the rotation axis mean?
It varies 1.5 degrees in either direction; essentially, we are moving the polar circles and tropics.
What is the procession of the equinoxes?
The wobble of a top; essentially, it changes which hemisphere points toward the sun when the Earth is closest to the sun.
How are the effects of the Milankovich cycles amplified?
The can be amplified by coinciding with each other, volcanic activity, El Nino, and greenhouse gas warming.
What effect does volcanic activity have on climate?
It can produce short term cooling by ejecting ash into the atmosphere, increasing albedo and essentially blocking out the sun.
Explain the carbon cycle.
Terrestrial vegetation absorb carbon until their deaths when they will release carbon under dry conditions and methane under wet conditions. We have not been able to quantify the oceans’ contribution to the carbon cycle yet.
Describe and explain the post-industrial increase in carbon dioxide levels in the atmosphere.
There was a sudden spike in carbon dioxide levels in the atmosphere around the 1700’s because of the Industrial Revolution. All of a sudden, we were burning coal.
What is the role of natural and anthropogenic factors in climate change?
They both contribute and both can have “forcing” effects.
Why is there stratospheric cooling?
There is less ozone to absorb ultraviolet radiation.
Explain how climate change models work.
We are interested in energy in and out, and how this is distributed over the Earth; we wrap our model Earth in a series of little boxes, run some fancy math, and then study what happens in these little cubes and the interrelation among all the cubes.
What are scenarios?
We don’t have climate forecasts because human activity and choice will affect what happens, so we model possible scenarios. There is no predestined amount of carbon that will be in the atmosphere.
What are three likely impacts of climate change on human health?
It will alter the distribution of some infectious disease vectors (e.g. mosquito distribution), it will alter the seasonal distribution of some allergenic pollen species, and it will increase heat-wave related deaths (e.g. 15 000 in France that one year!).
What are the likely impacts of climate change on water resources?
We will see changes in runoff and the recurrence of droughts. In Canada, resources are likely to increase due to melting ice and increasing precipitation, whereas in the States we’re likely to see decreases in resources.
What are the likely impacts of climate change on agriculture?
Yields are projected to decrease in tropics and sub-tropics but increase in the higher latitudes.
What are the likely impacts of climate change on coasts and oceans?
Rising sea levels will affect sensitive coral, coastal erosion, populations in low-lying areas of S.Asia and S.Pacific, and the health of habitats like mangrove forests or everglades.
Why do sea levels rise with warming?
Water expands and ice melts.
What is peer-reviewed research?
If an article gets past the first glance of an editor, it is then sent to other scientists in the field to be reviewed.
What is wrong with ad hominem attacks in the climate change debate?
Everything. They are often red herrings.
How can selective data use obscure the climate record?
Climate records are meant to be long-term, not taken out of context in short-term chunks.
Draw the carbon cycle.
Draw it!
What are some peer reviewed journals in geography?
Canadian Geographer, Annals of the Association of American Geographers, Journal of Climate
What do the Milankovich cycles explain?
Ice ages
What are scenarios?
“what if” predictions
What are emission scenarios based on?
dynamics and values?
Global/regional dynamics and economic/environmental values
What are climate change models based on?
3-D models of the atmosphere and its interaction with Earth
Why do some volcanic eruptions have an impact on climate and others don’t?
You need a powerful enough eruption to get the ask high enough into the atmosphere. Some, like Hawaii, don’t even have ash.
Why is sea level falling on the west coast of Canada?
Plate tectonics
