FGCU Carbon Dioxide Concentrations Between Pre Industrial Earth & Current Earth Paper

This week, we will be using an online climate model called “Build your own earth” to explore past, present and future climate.

What is Build Your Own Earth? Background information from the Build Your Own Earth Creators

Build Your Own Earth (BYOE; http://www.buildyourownearth.com) was a vision that we had to engage students in understanding the controls on Earth’s climate. The vision was for you to select the features you wanted in order to build the planet of your choice: distance from the Sun, tilt of the axis, location of continents, oceans and mountains, rotation rate, atmospheric composition, etc. You would enter these characteristics on a web page, and push the “Go” button. A climate model would run in the background and produce the climate on that world for you. Sounds fun, huh?

Unfortunately, such a vision is not currently possible with the speed of today’s computers. Even using a simplified climate model that is built for speed (FOAM: the Fast Ocean–Atmosphere Model), our supercomputer will only run about 480 years of model climate in one day. Even at coarse grid spacing, you’d need about 50–300 years of simulations to obtain a stable climate! Plus, with a number of students submitting simulations in real time, our supercomputer would be inundated with requests. Instead, we preselected about 50 Earths, did the computer simulations already, and prepared plots of the simulation results for you to examine. Our preselected Earths are in three categories: Recent, Ancient, Alien.

Recent Earths include a Current Day (2015) simulation with 400 ppm of carbon dioxide in the atmosphere (find today’s carbon dioxide concentration here: https://www.co2.earth/ (Links to an external site.)). We also have a preindustrial control simulation and a simulation from 1975. And, to show you the importance of the greenhouse gases to Earth, we have one where the atmosphere has no greenhouse gases. We also have simulations where we’ve changed the carbon dioxide concentrations (including some from our possible future!), the amount of solar radiation received by the Earth, and orbital parameters of the Earth (axial tilt and eccentricity).

Ancient Earths include snapshots from past geologic eras such as the Last Glacial Maximum (21,000 years ago), through the Miocene, Jurassic, Triassic, Carboniferous, Cambrian, and Ediacaran. We have taken paleogeography reconstructions from Colorado Plateau Geosystems along with atmospheric composition reconstructions.

Alien Earths are simple climate model experiments to abstract the climate down to its essence. What is the effect of no continents on Earth (Aquaplanet)? What would the circulation look like in a Snowball Earth episode (Iceplanet, which would be very much like Hoth from The Empire Strikes Back)? What would happen if a single continent existed on the equator? Or on the pole? What if the whole Earth was land except for a single ocean in the middle?

– Prof. David Schultz and Dr. Jonathan Fairman, Centre for Atmospheric Sciences Stuart Anderson and Sharon Gardner, eLearning Team

Your Assignment: Ok, Let’s Try it out! Go to the Build Your Own Earth website.

Website: http://www.buildyourownearth.com/index.html (Links to an external site.)

Now you can learn how to use the website in two ways:

1. Go to “Take a Tour” on the front page instead of clicking on “Get Started”
2. Watch the Tutorials if you are still confused: http://www.buildyourownearth.com/tutorials.html (Links to an external site.)

Part 1: Some Basics. 

1. Exploring the Last Ice Age

Set Earth 1: Ancient. 21 Ka: Last Glacial Maximum. This was the most recent ice age. 

Set Earth 2: Recent. Current Day 2015

Climate property should be set on Atmosphere: Mean Temperature, Surface for both Earths. 

Pressing play will show you temperature changes within 1 year. 

The sliding bar at the top will allow you to see the differences between your earth 1 and earth 2. You should see a change between the two. 

1. Stop your simulation on a nice summer day in July. What is the average July temperature in Seattle during the last glacial maximum?
2. Now slide to Current day. What is the average July temperature in Seattle today (note that the scale is in Celsius. 20 degrees C is about 68 degrees F).
3. No Greenhouse Gases.

Set Earth 1: Recent. No Greenhouse Gases. 

Set Earth 2: Recent. Current Day 2015. 

Climate property stays on Atmosphere: Mean Temperature, Surface

1. What happens to the Earth if there were NO greenhouse gases? Why?
2. What part of the earth would not be frozen the no greenhouse gas scenario?
3. What are the non anthropogenic sources of greenhouse gases (not caused by humans)?

Part 2: Climate Change

1. Look at the bar graphs showing the atmospheric gases (“view properties” not the climate model). Set your Earth 1 to be on Preindustrial Control (around 1700) and your Earth 2 to be on Recent, Current Day 2015.
2. What are the CO2 concentrations between Preindustrial earth and current earth? Why is there a difference?
3. N2O mostly comes from agriculture. How does N2O change from preindustrial earth to today?
4. How are the methane concentrations different between preindustrial earth and today? Why is there a change?
5. You probably remember CFCs as the major chemical destroying the ozone layer. Turns out they are also greenhouse gases. Why are there no CFCs in preindustrial earth?   

Let’s look into the future. Set Earth 1 to be on Recent, Current Day 2015. Set Earth 2 to Recent/CO2/ Set level=IPCC A1F1 CO2 Scenario. This is a hypothesized future with continued fossil fuel use, some advances in energy technology but with no major shift to alternative fuels until we are forced to. “Forced to” happens in about 2050, when global economies crash along with emissions. Keep looking at just the gas properties.

1. What is the CO2 concentration differences between the 2 models? The scenario says the global economy crashed, so why do you think CO2 concentrations still high in 2100? 
2. What are the methane concentration differences between the 2 models? 
3. Can you hypothesize why methane concentrations decreased but CO2 went up?

This is the end of the Homework assignment portion. Upload your answers to Parts 1 and 2 in the Assignment dropbox.

Part 3: Design your Own Experiment: This part of the assignment goes in the DISCUSSION FORUM for this week so you can share with your classmates. 

You will be coming up with your own “experiment” using the Build your Own Earth model. What does that mean? You will be asking a question, coming up with a hypothesis, running the simulation model to test your hypothesis, and supporting or rejecting your hypothesis.

The Build your Own Earth model is set up so that your independent variables are in the top box on the left side under “Earth”. These variables include, but are not limited to: time (ancient scenarios up to future), CO2 concentrations, solar energy (e.g. flares), Axial tilt, Eccentricity of orbit (how round the orbit around the sun is), and land mass locations. You should pick just ONE independent variable.

The dependent or response variables are in the lower box on the left side under “Climate Property”. The variable we’ve been looking at has been mean surface temperatures, but you could change it to be precipitation, clouds, winds, radiation, sea ice and snow, albedo, temperatures at higher altitude. Note that there are a few things that aren’t modeled, like vegetation. You should pick ONE dependent variable.

So all you have to do is pick one indepdendent variable to change between Earth 1 and 2 and see how it affects the dependent variable.

Hints: Be sure to change both earths to the same dependent variable. The more specific you are in your hypothesis, the easier it will be to test it!

In your DISCUSSION POST, answer the following:

1. What is your Research Question?

Example: What is the effect of changing _____ on ___________? 

1. What is your hypothesis?

Example: When _________________ is compared to _________________, then we will see an increase/decrease in ______________.  I think this will happen because ___________________

1. What are your results?
2. Do your results support your hypothesis? Do you find this surprising and why/why not?