Creating MAGICC Scenario Files

How to create your own emission scenario file for MAGICC6?

This is a quick recipe of how you can put your data into a ASCII fileformat that will work with MAGICC. Example files of the RCP scenarios can be downloaded from the RCP concentration calculations site [only links labled "MAGICC"], e.g. RCP3-PD (sometimes as well called RCP2.6), RCP45, RCP6, or RCP85. Suitable scenario files have always the extension *.SCEN.

What ingredients do you need?

1. In order to create an emission scenario file, you need the emission scenario data. Specifically, you need:

• Fossil / Industrial carbon dioxide CO2 emissions in units GtC/yr (to convert from GtCO2/yr to GtC/yr, multiply by '12/44')
• Landuse carbon dioxide CO2 emissions in units GtC/yr
• Methane CH4 emissions in units MtCH4/yr
• Nitrous oxide N2O emissions in units MtN/yr (note that to convert from MtN2O/yr to MtN/yr, multiply by '28/(28+16)')
• Sulphate dioxide SO2 emissions in units MtS/yr
• Carbon monoxide CO emissions in units MtCO/yr
• Non-Methane Volatile Organic compounds NMVOC in units Mt/yr
• Nitrogen Oxides NOx in units MtN/yr
• Black Carbon BC in units Mt/yr
• Organic Carbon OC in units Mt/yr
• Ammonium NH3 in MtN/yr
• Perfluorocarbons PFCs in the units kt/yr, namely CF4, C2F6, C6F14
• Hydrofluorocarbons HFCs in the units kt/yr, namely HFC23, HFC32, HFC43-10, HFC125, HFC134a, HFC143a, HFC227ea, HFC245fa
• Sulfur hexafluoride SF6 in units kt/yr

2. You need all these emission trajectories on the same points in time. MAGICC assumes linear interpolation between any years that are not provided. Thus, your time axis could either be 2000, 2005, 2050 and 2100, or, annual values or any other sequence of years as long as they monotonically increase. Note that historical emissions files are overwritten from the startpoint onwards, i.e. with the startpoint being your first year of your emission scenario, i.e. 2000 or 1990 or 2005.

3. Optionally, you can prescribe all this data regionally. This has the advantage that MAGICC does not have to make guesses on what the regional distribution of your emissions are over time. The regional split up follows the five RCP regions, i.e. OECD, REF, ASIA, MAF and LAM, (where MAF and LAM are together the former ALM region of the SRES scenarios), as defined here. In addition, you should specify emissions from international transport (i.e. the sum of aviation and shipping emissions) separately as the sixth region. Note that if you provide regional data, MAGICC expects the order of these data blocks to be GLOBAL, OECD, REF, ASIA, MAF, LAM, BUNKERS. And yes, globally aggregate emissions should be provided as well (although they will be ignored, if MAGICC is told to use the regional data..).

How do I format my scenario data?

Now that you have all your data, you have to take into account some formatting requirements of your ASCII .SCEN file.

• Your file ending should be ".SCEN" and it should be an ASCII file under DOS standard.
• The first line in your ASCII file consists of only one integer, ("20" in the example below), which specifies the number of prescribed years of your emission trajectory. For example, if your emission scenario is specified for the years, 2000, 2005, 2050 and 2100, then "4" is the number you should put into the top left corner of your ASCII file.
• The second line consists of only one integer. Simplified speaking, this integer stands for whether you provide global data or regional data. The options are:
  • 11 - Global/World data only.
  • 21 - Global/World data plus the four SRES regions OECD90, REF, ASIA and ALM. See regional definition here.
  • 31 - Global/World data plus the five RCP regions OECD, REF, ASIA, MAF and LAM.
  • 41 - Global/World data plus the five RCP regions OECD, REF, ASIA, MAF and LAM and international transport "BUNKERS".
• The third line specifies the scenario name. Usually identical to the filename.
• The fourth and fifth line are there for describing your scenario.
• The sixth line is empty.
• The seventh line contains WORLD as the regional definition for the first datablock.
• The eights line contains first the YEARS column header and then the headers with the list of gases (note, column order is not variable, but fixed as shown in the example below).
• The ninth line contains the units (only for the viewer as MAGICC expects the data to be in units as specified above).
• The tenth line is the first data line. Note that the field width has to be 11 for every data column - with the years being integers and the other emissions being floating point numbers with four digits after the dot, as MAGICC uses the Fortran command READ(FILE_ID , '(I11 , 24F11.4)') to read in these datablock lines.
• There are X data lines in total (including line 10), with X being the integer read in in the first line.
• Afterwards, there are TWO empty lines as separator
• Then, if regional flag is not set to 11, the header for the next regional block comes, i.e. "OECD".
• Then there is one line with column headers (i.e. years and gas names)
• Then there is one line with Units
• Then comes the next data block and so on..
• After the last data block, two empty lines are again provided as separator.
• Below these two empty lines, additional comments can be inserted, which will be ignored by MAGICC.

Please note: If you create unexpected curves with your scenario

Please make sure that your data start in line 10 and end in line 10 + the value from line 1. For example, adding an extra empty line between YEARS and UNITS or discard a comment line (line 3 or 4) will corrupt the SCEN file.

Example file

This is how the header and first dataline of an emission scenario .SCEN file should look like. In this example, an array of 20 annual datapoints has been provided (hence first integer in line 1 being "20"), and the data is provided with regional detail of the RCP regions (plus bunkers) (hence "41" in second line, see description above). For full examples, see these files RCP3-PD (sometimes as well called RCP2.6), RCP45, RCP6, or RCP85.

 20
 41
 RCP3PD
 HARMONISED, EXTENDED FINAL RCP3-PD (Peak&Decline) Emission scenario for MAGICC6
 DATE: 26/11/2009 11:29:06; MAGICC-VERSION: 6.3.09, 25 November 2009

 WORLD
      YEARS  FossilCO2   OtherCO2        CH4        N2O        SOx         CO      NMVOC        NOx         BC         OC        NH3        CF4       C2F6      C6F14      HFC23      HFC32   HFC43-10     HFC125    HFC134a    HFC143a   HFC227ea   HFC245fa        SF6
        Yrs        GtC        GtC      MtCH4    MtN2O-N        MtS       MtCO         Mt        MtN         Mt         Mt        MtN         kt         kt         kt         kt         kt         kt         kt         kt         kt         kt         kt         kt
       2000     6.7350     1.1488   300.2070     7.4567    53.8413  1068.0009   210.6230    38.1623     7.8048    35.5434    40.0185    12.0000     2.3750     0.4624    10.3949     4.0000     0.0000     8.5381    75.0394     6.2341     1.9510    17.9257     5.5382 
       2001     6.8960     1.1320   303.4093     7.5029    54.4192  1066.7447   211.5938    38.2888     7.8946    35.7143    40.3916    11.9250     2.4344     0.4651    10.4328     5.3987     0.6470     9.0301    84.0409     7.4947     1.6450    19.7183     5.6990 
       2002     6.9490     1.2317   306.5787     7.5487    54.9960  1065.4692   212.5632    38.4153     7.9841    35.8846    40.7647    11.8480     2.4915     0.4058    10.4708     6.7974     1.2941     9.8853    94.7162     8.7389     2.5080    21.5109     5.8596 
       2003     7.2860     1.2256   309.7165     7.5942    55.5716  1064.1742   213.5311    38.5418     8.0734    36.0543    41.1377    11.7692     2.5464     0.3939    10.5083     8.1961     1.9411    12.0788   101.4157     9.9776     3.3410    23.3034     6.0202 
       2004     7.6720     1.2428   312.8241     7.6394    56.1461  1062.8596   214.4977    38.6683     8.1624    36.2233    41.5107    11.6885     2.5990     0.4062    10.5455     9.5948     2.5881    12.5074   113.9297    11.2136     4.2690    25.0960     6.1806

...

Then, simply upload your scenario file on live.magicc.org and calculate climate effects following your own emission scenario.