A Few Climate Analogies
- The Earth’s climate system is like a room full of dancers, some leaders, some followers, but instead of being in pairs, they are all connected and all responding to each other. Climate change is a physical, complex, sensitive series of actions and reactions.
- The climate system is not like Vegas. What happens in one place does not stay there.
Climate Activities (Past, Present, and Future)
5. GLOBAL CLIMATE MAPS
Ever wanted to look at a map of global, mean annual temperature? How about Earth’s topography and bathymetry? Then compare how elevation influences temperature? Now you can!! I find most of the maps below by doing a Google Image search for what I want. It is good to look at seasonal variability instead of mean annual climate, and also to look at modern climate data versus 50 years ago. I start by showing a map, asking the student what they think the map is showing, having the students make observations, and seeing how their local climate is different from other areas (observation and exploration leads to excellent questions and understanding of the Earth’s climate). My favorite website for exploring these parameters is The Climate Reanalyzer
4. CLIMATE FEEDBACKS
The five components of Earth’s climate system are the oceans, atmosphere, biosphere, cryosphere, and land surface. They interact with each other in a leader-follower or cause-and-effect manor called feedbacks. For example, when the atmosphere warms, vegetation and forests expand to higher latitudes, this decreases the amount of sunlight reflected from the land surface (albedo) causing more sunlight to be absorbed, which results in more atmospheric warming. Ask the students to search for a ‘climate feedback’, do some research, and create a cartoon or drawing to explain how this feedback works to their peers. Also talk about positive and negative feedbacks (positive AMPLIFIES the initial change in climate, i.e. warm gets Warmer; negative decreases the initial change in climate, i.e. neutralizing the change).
Examples of climate feedbacks:
- Warming -> more moisture in the atmosphere -> more clouds -> more sunlight is reflected back into space -> results in a cooling (NEGATIVE feedback)
- Warming -> more moisture in the atmosphere -> more rainfall in some areas -> increased vegetation cover -> darkens the Earth’s surface -> more sunlight is absorbed -> results in a warming (POSITIVE feedback)
- Warming -> Sea ice lasts for shorter time of the year -> more sunlight is absorbed because the ocean is much darker than the sea ice -> results in a warming (POSITIVE feedback)
3. OCEANS AND CARBON DIOXIDE, USING SODA
Materials: Five bottles of soda, five balloons, salt, perhaps an outside space and lab coats and goggles?
The ocean contains dissolved carbon dioxide. Lots of it. There are several physical changes to ocean water that will influence how much carbon dioxide a parcel of water can ‘hold’. The soda is a carbonated beverage, meaning it has been pumped full of carbon dioxide to give the drink its fizz.
How do you keep soda from going flat (in other words, how do you keep CO2 in the ocean)? (Let students pair up and brainstorm different ways for 5 minutes).
Ask the students to share their ideas, might be something like:
- Keep the soda cold (colder water can hold more CO2)
- Keep the soda under pressure (water at the bottom of the ocean is under VERY HIGH pressure because of the weight of the overlying water
- Don’t shake the soda bottle (ocean water that stays still or calm will not release as much CO2 as water crashing against coasts or in massive surface waves)
If you are willing, and can go outside, you can test these theories but putting a balloon over the top of each soda bottle and opening the cap and seeing how much the gas fills up the balloon (the shaken bottle might be a mess).
There is a fourth physical component that can influence how much CO2 a parcel of ocean can hold
4. Adding salt to the soda causes it to degas (saltier ocean water will release more CO2 into the atmosphere than fresher water)
I’m not sure how to test this one while keeping a balloon over the top, let me know if you have an idea.
Discussion: How is soda like the ocean? The ocean stores a lot of carbon dioxide, not nearly as much as rocks, but more than that stored in the atmosphere. If the ocean becomes WARMER, it can’t hold as much CO2 and releases the gas to the atmosphere, which results in warming of the atmosphere because CO2 is a Greenhouse gas.
This website is an amazing visualization tool. Click on ‘earth’ in the lower left corner to change options. Allow the students time and space to watch this, change some options, and make observations, this is plenty.
Some leading questions:
- Where are the FASTEST winds? (Southern Hemisphere westerlies usually, or if they figure out how to go higher in the atmosphere, they could find the jet streams!)
- Are surface winds faster over the ocean or land? Why do you think that is? (ocean, less friction)
- Find a cyclone (storm), is it in the northern hemisphere or southern hemisphere? Is it spinning clockwise or counterclockwise? (Cyclones/Low pressure systems should turn counterclockwise in the northern hemisphere)
A few fundamentals that you can look for:
- High pressure systems spin clockwise in the northern hemisphere and counter-clockwise in the southern hemisphere
- High and low pressure systems spin in opposite directions in the same hemisphere
- Low pressure systems are generally associated with precipitation because air is rising and air moisture is condensing, while high pressure systems are associated with clear weather because air is descending from high in the atmosphere
- Air masses over the ocean are generally wetter
- Air masses over tropical ocean are wetter than those over colder oceans
- Winds moving air masses from the ocean to land generally bring precipitation
- Mountain ranges act as a barrier to the winds and can cause heavy rainfall on one side of the mountains (where air is rising) and dry conditions on the opposite side (where air is descending)
1. OCEAN STRATIFICATION (4-12 grade)
Warning: This has not been tested and could be complete chaos, but I love the idea, let me know how it goes!
Materials: 1 bowl of hot/warm water, 1 bowl of very cold water, dish containing a few tablespoons of salt, 1 stirrer (spoon, popsicle stick, or knife), 1 empty clear, water-tight bowl or dish to do the experiment in, 2 different colors of food coloring (or you can color the cold and warm water differently beforehand), 2 thermometers if available, ice cubes made with water and blue food coloring, camera, per group, don’t hand these out until you accept their experimental design.
Goals: See how temperature and salinity influence the density of water and thus the vertical movement of water that happens when the a dense water on top flows down to the bottom. Think about how these two properties (temp and salinity) influence ocean circulation and stratification (layering).
Experiment: The students are going to design their own experiment after watching these videos and looking at the maps of sea surface temperature and salinity (saltiness):
Search for maps of Sea Surface Salinity on the web to see where ocean water is fresher or saltier.
Tell the students what materials are available to them, and that they get to design their own experiment. Put these questions on the board: Do you want to study: Cold vs warm? Salty vs fresh? Cold and fresh vs warm and salty? Iceberg melting? Based on the videos you watched, what do they think will happen in your experiment?
Alice’s experiment (high school level): I would mix salt into the cold water, I would pour this into the empty dish first. I would slowly add the warm water keeping the container near the cold water surface so mixing doesn’t happen. If they two waters (cold and salty and warm and fresh) stay separated, I would then add an ice cube or two. The ice cube is cold and fresh, so I would predict that the blue water from the ice cube would sink through the warm fresh water, but not through the cold salty water. I’m curious if very cold fresh water would be more dense than cool salty water.
Now you can hand out the materials. They can add a drop or two (not as much as in the video) of the food coloring into their cold and/or warm water to see the stratification/layering/separation. Make sure they know that the warm and cold waters could mix if they pour in liquid too quickly. If you come up with a good way of pouring the waters without too much mixing, let me know. Now they can run their experiment.
Discussion: Have each group present what they did (methods), their prediction of what would happen based on previous observations/knowledge (hypothesis), what happened – show photos if possible (results), and how this could relate to the world’s oceans (where are icebergs floating? Where do salty and fresh waters meet? Where do cold and warm waters meet?)