As A-P mentioned before, measuring methodology is important to find solutions. To solve the Greenhouse gas effects, measuring the amount of gas and analyzing their affect is important. One of the way to measure the greenhouse gas is Greenhouse gas inventory.
A greenhouse gas inventory is an accounting of greenhouse gases(GHGs) which is emitted to or removed from the atmosphere over a period time. This inventory includes not only emissions from source categories, but also removals by carbon sinks which are typically referred to as carbon sequestration.
Planners use these inventories to establish a baseline for tracking emission trends, developing mitigation strategies and assessing progress.
Then how can planners use this inventory to measure and analyze?
Diagram-1 shows 6 steps of “Low Carbon City Planning Cycle”. This inventory can be used at the first and last step. By using this inventory, urban planner can quantify the amount of greenhouse gas emissions to understand city’s emission patterns and identify the major sources of emissions as well as reduction opportunities from both direct and indirect sources. And according to this data, planner can analyze future scenario, set a target, make action plan, implements it to policy. After that planer can compare the adjust it to last step, planner can compare last year emission quantity and this year quantity by using Greenhouse gas inventory.
Estimating GHG emissions enables local governments to create an emissions baseline, monitor progress, assess the relative contributions of emission sources, communicate with stakeholders, and create an informed mitigation strategy based on this information.
There are two different inventories that are used in King County; The Geographic-plus inventory and The Consumption-based Inventory. The Geographic-plus inventory estimates the annual Greenhouse gas emissions released within King County. And the Consumption-based Inventory used to quantify the emissions associated with consumption of all goods and services by King County residents and governments. By using these two inventories King county develops ongoing measurement framework to support King County in its efforts to assess key sources of GHG emissions.
Greenhouse gas inventory is necessary to quantify total emissions. By using these data, planners can set a future plans and makes feedback by comparing different year data. To make reasonable plans to reduce GHG emissions, action plans should be based on accurate data. Also after measure data planers should need to set clear analysis like what is the main drivers for greenhouse gas emission and need direct action to solve it.
 Inventory of U.S. Greenhouse Gas Emissions and Sinks, accessed March 4, 2014,
 City and Community GHG Accoiunting