Like Nature
Science in focus

The carbon policy (carbon price) in GCAM is an important link in the study of low-carbon path. The carbon price can be exogenous or endogenous based on climate objectives. The example given by GCAM is carbon_tax_0.xml file. An example of endogenous formation is policy_target_1p9_spa1.xml, etc.

In addition to CO2, there are many other greenhouse gases in GCAM, such as CO and HFC. China's carbon neutralization policy is CO2 neutralization, while some European countries are greenhouse gas neutralization, which involves different definitions in GCAM. Let me analyze how to set different gas coverage s to simulate the policies of different countries if the carbon market is defined in GCAM.

In carbon_tax_0.xml file

<?xml version="1.0" encoding="UTF-8"?><scenario name="CCSP450">
    <world>
        <region name="USA">
            <ghgpolicy name="CO2_LTG">
                <market>global</market>
				<fixedTax year="2025">10</fixedTax>
				<fixedTax year="2030">12.762815625</fixedTax>
				<fixedTax year="2035">16.2889462677744</fixedTax>
				<fixedTax year="2040">20.7892817941137</fixedTax>
				<fixedTax year="2045">26.5329770514442</fixedTax>
				<fixedTax year="2050">33.8635494089939</fixedTax>
				<fixedTax year="2055">43.2194237515066</fixedTax>
				<fixedTax year="2060">55.1601536759225</fixedTax>
				<fixedTax year="2065">70.3998871212465</fixedTax>
				<fixedTax year="2070">89.8500779349281</fixedTax>
				<fixedTax year="2075">114.673997857537</fixedTax>
				<fixedTax year="2080">146.356309163739</fixedTax>
				<fixedTax year="2085">186.79185894123</fixedTax>
				<fixedTax year="2090">238.399005591792</fixedTax>
				<fixedTax year="2095">304.264255355139</fixedTax>
				<fixedTax year="2100">388.326859237556</fixedTax>
            </ghgpolicy>
        </region>

< region > this tag should be easy to understand, that is, the regions that accept the ghg policy. There are 32 regions in GCAM, so we have 32 choices.
< market > is also easy to understand. It is either global or each country itself, which limits the spatial scope of the carbon market in the region.
It should be understood that < ghgpolicy name = "CO2_LTG" > GCAM sets a carbon market through the ghgpolicy tag and gives it a name CO2_ LTG, in fact, is a virtual name because in gcam5 2, no CO2_ LTG gas, GCAM only forms a virtual market through this name. You can change it to CO2e, GHG or any name you like. So far, we have not introduced any emissions. To introduce real emissions, we need to pay attention to global_uct.xml

        <region name="USA">
            <linked-ghg-policy name="CO2_LUC">
                <market>USA</market>
                <linked-policy>CO2</linked-policy>
                <price-adjust year="1975" fillout="1">1.0</price-adjust>
                <demand-adjust year="1975" fillout="1">0.0</demand-adjust>
                <price-unit>1990$/tC</price-unit>
                <output-unit>MTC</output-unit>
            </linked-ghg-policy>
        </region>

global_ uct. The linked GHG policytag in XML puts the gas you want into the "CO2_LTG" market we set in the previous file. You can give any gas allowed by GCAM here, such as CO2, CO and CO2_ Luc, wait,

Price adjust and demand adjust respectively determine the equivalent way to put this gas into the emission market. For example, CH4 can be equivalent to 25 times CO2

----
I'm a doctoral student at Renho University( My google scholar, My Github ), pay attention to environmental and economic issues in the process of energy transformation.

Focus on sharing the skills of using python scientific research. Welcome to communicate, learn and cooperate with us.

For my blog content and other related research questions, please click below 👇 Comments, or private letters to me~