Wow this course is hard. My 42 year old brain is not only trying to read and understand the information but then to explain the information (even if it is just to my blog). This is something I haven't had to do a in over 15 years (when I finished my last degree). I can usually correctly answer the multiple choice questions but the following more open ended questions, are challenging. Which probably means I have a ways to go to be able to explain it to someone else in a way that makes sense to them.
What are the key scientific principles that explain climate change including the greenhouse (blanket) effect?
- the earth's atmosphere has important "Greenhouse gases" that act like a blanket around the earth allowing sunlight (short wave radiation) in. This radiation can pass through the gasses and then be absorbed by the the earth's surface and the living things on it but it can also be reflected back towards space. The Green house gases can now absorb/trap this reflected back long wave radiation and then re-emit it back to the earth keeping the earth's surface warm (and liveable).
- the Greenhouse gases that act like this blanket are water vapour, carbon dioxide, methane, nitrous oxide and ozone
- Human activity has caused changes (increases) in the concentrations of these gases which means more radiation is being reasborbed and re-emitted back to the earth surface and warming the temperature.
What are the key feedback mechanisms that help to explain why our climate is able to “self-regulate"?
This is definitely a question I am not sure I understand so not sure how to provide the "correct" response.
The key feedback mechanisms seem to refer mostly feedback loops as they relate to warming. So activities that are ampliflying or increasing the warming process would be called positive feedback mechanisms (for example the Albedo feedback where warming of the oceans means the melting of more sea ice which means less ability of the sea ice to reflect back solar radiation which leads to more warming of the earth's surface and the oceans). The course also referred to water vapour feedback as a positive feedback where increased warming leads to increased evaporation which leads to more water vapour in the atmosphere that traps reflected radiation and sends it back to the earth's surface.
However, The NASA Earth System science site also refers to increased evaporation as a negative feedback system where increased evaporation increases cloud cover which can reflect back sunlight before it enters into the atmosphere and therefore preventing it from coming to the earth's surface.
I believe the self regulation component (and important negative feedback mechanism) described in both the course and the NASA site is radiation feedback were the Stefan Boltmann's law states that as the earth's temperature warms, it will increase its emission of infrared radiation back into space allowing the Earth to experience a slight cooling effect.
How can our climate be conceptualized as a system containing a series of components that interact with one another?
The earth is a system of interacting parts. These parts include the atmosphere (the gases encompassing the earth), the hydrosphere (the oceans, rivers and lakes), the cryosphere (glaciers, sea ice and ice fields), the biosphere (plants, animals, insects, soils) and the lithosphere (the earth's crust). An example of the interaction of the systems is sunlight radiation along with carbon dioxide and water vapour already present in the atmosphere being used by plants in the biosphere to photosynthesize and release oxygen back into the atmosphere. Because parts are so interconnected, the feedback mechanisms are really complex.
What are the key scientific principles that explain climate change including the greenhouse (blanket) effect?
- the earth's atmosphere has important "Greenhouse gases" that act like a blanket around the earth allowing sunlight (short wave radiation) in. This radiation can pass through the gasses and then be absorbed by the the earth's surface and the living things on it but it can also be reflected back towards space. The Green house gases can now absorb/trap this reflected back long wave radiation and then re-emit it back to the earth keeping the earth's surface warm (and liveable).
- the Greenhouse gases that act like this blanket are water vapour, carbon dioxide, methane, nitrous oxide and ozone
- Human activity has caused changes (increases) in the concentrations of these gases which means more radiation is being reasborbed and re-emitted back to the earth surface and warming the temperature.
What are the key feedback mechanisms that help to explain why our climate is able to “self-regulate"?
This is definitely a question I am not sure I understand so not sure how to provide the "correct" response.
The key feedback mechanisms seem to refer mostly feedback loops as they relate to warming. So activities that are ampliflying or increasing the warming process would be called positive feedback mechanisms (for example the Albedo feedback where warming of the oceans means the melting of more sea ice which means less ability of the sea ice to reflect back solar radiation which leads to more warming of the earth's surface and the oceans). The course also referred to water vapour feedback as a positive feedback where increased warming leads to increased evaporation which leads to more water vapour in the atmosphere that traps reflected radiation and sends it back to the earth's surface.
However, The NASA Earth System science site also refers to increased evaporation as a negative feedback system where increased evaporation increases cloud cover which can reflect back sunlight before it enters into the atmosphere and therefore preventing it from coming to the earth's surface.
I believe the self regulation component (and important negative feedback mechanism) described in both the course and the NASA site is radiation feedback were the Stefan Boltmann's law states that as the earth's temperature warms, it will increase its emission of infrared radiation back into space allowing the Earth to experience a slight cooling effect.
How can our climate be conceptualized as a system containing a series of components that interact with one another?
The earth is a system of interacting parts. These parts include the atmosphere (the gases encompassing the earth), the hydrosphere (the oceans, rivers and lakes), the cryosphere (glaciers, sea ice and ice fields), the biosphere (plants, animals, insects, soils) and the lithosphere (the earth's crust). An example of the interaction of the systems is sunlight radiation along with carbon dioxide and water vapour already present in the atmosphere being used by plants in the biosphere to photosynthesize and release oxygen back into the atmosphere. Because parts are so interconnected, the feedback mechanisms are really complex.
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