MAGICC6 User FAQ

This page provides you with some of the common questions that you might come across, when using MAGICC6, either via our webinterface or when using the downloadable Windows executable.

General Questions

Is MAGICC6 the best climate model ever?

Certainly not. MAGICC6 is a reduced-complexity climate model that attempts to synthesize current scientific understanding about many different gas-cycles, including the carbon cycle, climate feedbacks and radiative forcing. The strength of MAGICC is that it is sufficiently flexible to be able to closely emulate the large and complex climate models, sufficiently physically based to allow credible interpolations and indicative extrapolation near the calibration range. Furthermore, MAGICC6 is fast. That is an advantage, particularly for producing probabilistic projections for new emission scenarios, a process that is computationally unfeasible with the complex climate models. Thus, with due respect, if the question is whether MAGICC6 is the best method around to synthesize a whole range of climate and carbon cycle knowledge for probabilistic projections over the 21st century and beyond, we are inclined to say "yes". MAGICC6 thereby only complements, rather than aiming to replace, any complex climate models (simply because MAGICC6 is closely calibrated towards these "big brothers").

I am teaching a class on climate. How can I use MAGICC?

Probably the best method is to use our online web-interface live.magicc.org

Questions related to live.magicc.org

Which version does liveMAGICC use?

liveMAGICC currently uses MAGICC6.

How do I use liveMAGICC?

Well, that's easy.

When you're entering liveMAGICC you will see Tab 1 - Emissions where you can select one or more emission scenarios. Click NEXT to get to Tab 2 - Model Settings where you are able to tune the climate and carbon cycle settings for MAGICC (optional). Switch to Tab 3 - Climate to actually run MAGICC and view the results of the desired settings made on Tab 1 and Tab 2.

Find a step-by-step online Help for the use of liveMAGICC under Online Help.

How can I navigate through the tabs of liveMagicc?

You can navigate through the tabs by clicking the NEXT and BACK buttons or by clicking the Nutshells acting as tab titles. There is no difference between those two ways.

Tab 3 - Climate acts slightly different to the first two tabs. While you are switching between the forms on Tab 1 - Emissions and Tab 2 - Model Settings, clicking Tab 3 - Climate will result in a server request and will run Magicc on our server. Be sure that you made the desired settings on Tab 1 and 2 once you switch to Tab 3 - Climate since this will force the website to queue the task in the task list.

What is in Tab 1 - Emissions?

On the left is a list of scenarios available to run Magicc with. You can customize this list (not yet implemented) or it may be customized for you by your supervisor, teacher or class leader. You are also allowed to upload your own scenario files (SCEN-files) (not yet implemented).

Once you select one or more scenarios in the select box on the left the chart on the right will be refreshed and show the scenario pathway(s). You can navigate through the different emission variables by selecting an emission variable on top of the emission chart.

What is in Tab 2 - Model Settings?

In this tab one can change the run mode on the left and all model settings. There are two run modes, Standard and Probabilistic. In Standard mode one can specify climate parameters and carbon cycle settings on the right. In probabilistic mode one can choose from the probabilistic modes Multi-model-ensemble emulations (171) and Probabilistic / historical constrained (600). See ?? for detailed information.

What is in Tab 3 - Climate?

Tab 3 - Climate shows the results of the individually created Magicc runs. Note that the Magicc runs will be processed once you switch to that tab. On the left you can see your personal run list. The items are attached either to a checkbox or a spinning wheel, depending on their status. A currently processing run has a blue spinning wheel. A queued run (not yet processed run) has a grey spinning wheel. All runs in the queue will be processed in sequence. Depending on the runmode it takes seconds (single run mode) to minutes (bulk run mode) to process a run. For probabilistic runs a feedback of the process is displayed (e.g "Magicc run 34 of 171"). The checkbox marks runs as completely processed. A horizontal line in the run list divides standard runs (single runs) from probabilistic runs (bulk runs). The checkboxes allow for plotting. Checking and unchecking will refresh the climate chart on the right. You can compare as many runs as you desire. To change the plotted climate variable choose from the list on top of the chart.

How do I know what the different emission scenarios actually mean?

Well, there are many different ones. For example, the RCP scenarios are the new standard, used by the Coupled Model Intercomparison excercise Phase 5. The highest scenario is RCP8.5 with a steady increase of emissions throughout the century. RCP.6 is the next lower one, approximately a middle range non-climate-policy scenarios, when compared to the previous SRES scenarios. RCP4.5 is the next lower emission scenario, often considered as a lax mitigation scenarios. The lowest scenario is RCP2.6, or as well called RCP3-PD, which represents a stringent mitigation scenario. Out of the four RCPs, only the latter scenario RCP2.6/RCP3-PD has a likely chance to stay below 2-degree warming. In general, it is probably best, if you go to the first tab on live.magicc.org. If you select your emissions scenarios and select the emissions you want to see, you can see their emission trajectories graphically. Thus, you can compare any other emission scenario to the RCPs, for example.

If I select an emissions variable like "Fossil CO2" on Tab 1 - Emissions will I get different climate results ?

The selection of a emission path variable in the emission chart has no effect to the Magicc run. The emission chart is just for your information.

Can I run multiple emission scenarios at the same time?

You can do multiple selection of emission scenarios in the scenario select box on Tab 1 - Emissions. The procedure is dependent to your OS / browser. For Windows users: hold CTRL while selecting scenarios with the mouse or hold SHIFT to select a range of scenarios.

The multiple scenario selection will result in several tasks in Tab 3 - Climate that are queued to the users task list. Magicc will process them in sequence.

Note that multiple selection of scenarios is also available in Bulk Run Mode. This may result in a long term processing queue.

How can I select multiple climate or carbon cycle settings?

Choose a desired climate or carbon cycle setting and switch to Tab 3 - Climate. The run will be queued. Now return to Tab 2 - Model Settings and choose another desired climate or carbon cycle setting. You can repeat these steps as often as desired. If you choose an already-processed setting accidentally Magicc will not process that setting again. You get a message in the console (What is the console?) that the configuration has been skipped.

How can I compare the same emission scenario for two different climate settings?

Choose a desired climate or carbon cycle setting and switch to Tab 3 - Climate. The run will be queued. Now return to Tab 2 - Model Settings and choose another desired climate or carbon cycle setting. You can repeat these steps as often as desired.

How can I change only the climate sensitivity or other parameters?

Return to Tab 2 - Model Settings and change only desired parameters. Once you switch to Tab 3 - Climate the forms of Tab 1 and Tab 2 will be evaluated and only if changes were made Magicc will be executed.

Why is the carbon cycle setting important when I want to know about the climate ?

The carbon cycle is important as it determines the CO2 concentrations that result from CO2 emission pathways. There is some uncertainty on that link. The coupled carbon-cycle climate model MAGICC includes a simple terrestrial carbon cycle and oceanic component. You can select various C4MIP model calibrations to get a feeling for the uncertainty and importance of the carbon cycle response.

Where can I see my outputs?

You can see your outputs on Tab 3 - Climate. On the left you will see your individual run list. Checkboxes indicate the already processed runs. By checking / unchecking the checkboxes you select the runs that will be plotted in the chart on the right.

Can I plot different variables in the same plot?

No, that is not possible because different climate variables require different y-axes and units. The variable list is therefore a single select box.

Can I download the data that live.magicc.org created?

This feature is scheduled on high priority. Please, stay tuned to live.magicc.org.

How can I run create GHG concentrations according to the RCP default settings ?

If you choose the DEFAULT settings for both the climate and carbon cycle settings "SINGLERUN", your setting is the same as we used for creating the official RCP GHG concentrations. The reason, why you will get tiny differences in the concentration results (if you were to use the RCP emission pathways) compared to the official recommendations are things like ozone-depleting substance emissions. We had adapted those emissions for each RCP, but use a default emission profile in the background for this web-interface.

How can I share my results with another user?

This feature is scheduled on high priority. Please, stay tuned to live.magicc.org.

Why would I want to sign up with a User Account on live.magicc.org?

This allows you to resume a session as well as share your results with other users (This feature is scheduled on high priority. Please, stay tuned to our live.magicc.org).

What are the system requirements for participating in live.magicc.org?

You need a browser that is able to display our website. We tested our website for IE6, FF4, Opera7. To report a bug for your browser, please see the bug report section(??). You will need JavaScript. There are no requirements for your processor or any of your hardware since liveMagicc runs on our server.

How much does it cost?

The service is free to use. If you make any use of this work, please cite:

Meinshausen, M., S. C. B. Raper and T. M. L. Wigley (2011). "Emulating coupled atmosphere-ocean and carbon cycle models with a simpler model, MAGICC6: Part I – Model Description and Calibration." Atmospheric Chemistry and Physics 11: 1417-1456. doi:10.5194/acp-11-1417-2011

How can I save the graphs that I create?

This feature is scheduled on high priority. Please, stay tuned to live.magicc.org.