The workbook contains a number of separate, named, linked spreadsheets.
On opening the file, an information and copyright sheet is displayed. Please read this, then switch to the 'Control' sheet should be displayed, which contains all the user-adjustable parameters as well as the key numerical results and charts thereof.
We have tried to adhere to a convention that cells the user is encouraged to modify are shown in beige. Ones shown in red are particularly important not to modify.
For initial use, it is recommended that one of a number of standard scenarios is selected. These can be found in the scenarios sheet - the recommended ones are in columns B-K. To use one of these, just type its name eg r450 into cell B7 of the control sheet.
For normal use other than using a preset scenario, all that a user needs to do is to type a chosen set of values into the block of user-adjustable parameters, which in v8.6 is B7:B24 on the Control sheet. Do not type into other cells on the control sheet. Note that values in B8:B24 are ignored if a scenario name is typed into B7.
The values used are displayed in bold immediately to the right, in column C. When a scenario is used this gives visual display of the parameters used.
Changing anything else in the workbook, apart from the set of regions - see below - is not recommended unless you are confident you understand its workings in detail. But it should be safe to add extra computations or data if wanted.
On a fast PC, simply retyping a desired different set of parameter values results in the rapid recomputation of the results and chart(s). On a slower PC, it is better to use the Excel option to switch calculation to manual to avoid lengthy computation of unwanted intermediate results when changing several parameters.
The following parameters can be entered.
A set of plausible values, corresponding to a 450ppmv stabilisation scenario,
which the workbook is shipped with, are shown in the second column.
0.015
2075
0.01
0.28
442
450
0.02
|
Parameter |
Preset value |
| Optional named preset scenario of parameter values. CCOptions is shipped with it blank. If included, the other typed-in options are ignored. | (left blank) |
| Convergence year (can be up to 2100) | 2040 |
| Population cutoff year (can be up to 2050). | 2040 |
| Optional name of secondary scenario of contraction profile. If included, the other typed in options in the contraction section are ignored. | (left blank) |
| Initial year global industrial CO2 emissions growth rate (should not normally be changed) | 1.5% |
| Contraction year (can be up to 2100) | 2075 |
| Rate of decline of emissions in contraction year | 1% |
| Contraction level of industrial CO2 emissions (as % of 1995). ). This is the percentage that emission are planned to be reduced to. | 28% |
| Planned total 110-year industrial CO2 emissions (GTC). If the contraction year is earlier than 2100, CC Options will usually produce an outcome with a slightly smaller number than that input. | 442GTC |
| Target concentration in 2200 (for highish concentrations this value is approached but not reached) | 450ppmv |
| Emissions smoothing parameter ( between 0 and 1, the larger it is the faster the emissions profile nears its 2200 target) | 0.02 |
| Phase 2 start year. Normally set this to 2100, meaning there is no phase 2. Phase two gives an option of assessing the impact of a change of contraction policy in a given future year, the "phase 2 start year". | 2100 |
| The final six rows are a second set matching rows 12-17, i.e. all the contraction parameters can be changed for the Phase 2. | (left blank) |
Copious use has been made of the Excel Note facility—cells with explanatory notes have a small red dot in the upper right corner. In Excel v7 and later the note is displayed when the mouse hovers over that cell; in v5 you have to select "Insert/Note" or double-click on the cell to see it.
CCOptions is available in large and small versions. The small version is much faster and it is recommended that new users familiarise themselves by using this version initially. It performs the detailed calculations only on the selected regions (see below), not on the 200-odd individual countries.
There are two separate sets of ‘scenarios’ in CCOptions. There is nothing very special about them, they are just stored sets of parameters to the model. You can try out the different preset scenarios to get a feel for the range of possibile futures that CCOptions can encompass.
These consist of a stored set of values for the parameter list described above. The scenarios are stored in the ‘Scenarios’ worksheet in CCOptions, in columns A onward. Each is named in row 3, labelled "Reference". The one described above is "t1.5" and can be found in Column G.
To use an overall scenario, just type or copy-and-paste its name into cell B8 on the control sheet, at the top of the parameter block. The values in the parameter block below, from B9 to B25 are then ignored and it would be better for them not to be displayed, as they may confuse. We recommend deleting them manually before or after entering the scenario name. The values used by CCOptions are always those diplayed in column C.
To edit an overall scenario, a little care is required. Editing the scenario data in the scenario worksheet is not recommended, instead use the following procedure:
To create a new scenario, which you have created either by editing an old one or by any other method, proceed as follows:
To delete a scenario, just delete the column from the scenarios sheet.
These were added to enable CCOptions to explore CO2 emissions profiles generated by other models or suggested independently by anyone. Overall scenarios may use a contraction scenario. When you use a contraction scenario, either via an overall scenario or otherwise, the contraction profile part of CCOptions is replaced by directly using the values from the scenario. These values need to give global industrial CO2 emissions for every year from 2000 to 2100. If you have estimates from another model for fewer years, say 2025, 2050, 2075 and 2100 only, you will have to set up interpolation formulae; this is straightforward in Excel – we did it to create the preset contraction scenarios. The formulae we used were straightforward linear interpolations, and have been removed to speed up spreadsheet computations.
To add a new scenario, you need to insert a block of data to the left of the column, currently AY, headed "Insert extra contraction scenarios to the left of this column", and add a name into the reference row, currently row 3. Deletion is the reverse.
To use a contraction scenario, just type its name into cell B13 of the control sheet. The rest of the "Contraction" block, B14:B18 is then ignored and might as well be deleted. You will see that this has been done in those preset overall scenarios that use contraction scenarios.
Advanced users can select their own way of dividing up the world into regions.
As shipped it's basically divided by continent, with Europe split into East
and West parts and Asia split into East, West and South.
To change the set of regions:
1/ go to the regions sheet.
2/ type in the names of your selected regions into cells C5-Q5 (highlighted
in beige). Do not move cells in that row around directly as this will upset
Excel's formulae. If you want to make a small change, copy the existing set
to a blank work area, edit it there, and copy the lot back.
3/ replace the region names in row 3 where necessary with the relevant ones
of the new set of names corresponding to the countries in row 2 above. If the
number of regions is increase beyond the 10 as shipped, the regional totals
graph will need editing or re-creating to display all of them. A maximum of
15 regions can be specified.
Note that it's possible while doing this to reorder the regions (and/or the
countries as well). This only affects the order in which they are displayed
in an Excel chart. There is also no reason why a country may not be made a region
all by itself and there is no problem with a region name being the same as a
country name.
The majority of key results are displayed on the control sheet. The detailed allocations on which the chart displayed is based can be read in the allocatedCO2 sheet. There are also percapita CO2 emissions tables in a separate sheet, computed straightforwardly.