Is the database of GHG emission factor in LEAP system the latest one? or we need to update it by ourselves?
The basic Tier 1 emission factors in LEAP correspond pretty well to the IPCC Tier 1 methodology. However, the other emission factors in TED are now rather out-of-date, so you may need to add some of your own. You may also wish to draw upon a good set of emission factors we have provided here (in Excel format): https://leap.sei.org/default.asp?action=IBC#EFs.