Sectoral policies about gcam-core HOT 2 CLOSED

There are a few ways to make sector- or technology-specific policies; the one I've used before is to assign a separate CO2 object to the technologies of interest, in all years. For example, in shipping, you'd want to make an XML file with the following structure:
`

<world>
    <global-technology-database>
        <location-info sector-name="trn_shipping_intl" subsector-name="International Ship">
            <technology name="Liquids">
                <period year="1975">
                    <CO2 name="CO2_transport"/>

`

Of course copy that through to all years, for all technologies that you want. The CO2 emitted by the technology will be added to the CO2_transport market, which can then be constrained just as with any other market. The unit is Mt C (i.e., Mt CO2 times 12/44). Examples of the policy structure are in the committed input/policy folder.

`

<world>
    <region name="USA">
        <policy-portfolio-standard name="CO2_transport">
            <policyType>tax</policyType>
            <market>USA</market>
            <constraint year="2025">350</constraint>

`

from gcam-core.

Thank you very much, @pkyle. The suggested approach worked perfectly, and I was able to implement a policy specifically for the transport sector. I will go ahead and close the issue now. However, I would like to mention that for anyone attempting this in the future, it's important to note that following this approach would result in double-counting of CO2 emissions from the sector. Nevertheless, the policy still functions as intended.

from gcam-core.