MAGICC6 User FAQ

This page provides answers to common questions, encountered when using MAGICC6 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". Thus, MAGICC6 aims to complement, rather than 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, the same version which was used to generate the RCP greenhouse gas concentrations.

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

There are many possible global emission pathways for different purposes and assumptions. 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 on 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 (you don't have to wait for the results) and choose another desired climate or carbon cycle setting. You can repeat these steps as often as desired. Identical model configurations will not be executed twice, so you don't need to take care of this.

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 the desired parameters. Once you switch to Tab 3 - Climate the forms of Tab 1 and Tab 2 will be evaluated and 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?

You are able to download the results when you are registered and logged in. In your run list on Tab 3 - Climate you find a download link in the tooltips of the runs.

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). Also it allows to upload own emission scenarios and to download the results of the MAGICC runs.

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. You will need to enable JavaScript. There are no requirements for your processor or any of your hardware as MAGICC runs on our server.

How can I extend the output inteval to e.g. 2500

That feature is not offered or planned in the online version. Please use the desktop version of MAGICC6 and change the paramtere ENDYEAR in /MAGICC_MAIN/MAGCFG_NMLYEARS.CFG to do so.

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?