No. There is no physical traceability of the renewable energy from point of generation to end-use consumption in a pooled grid. Transactions of RECs or GOs do not alter this physical reality. Nor are these certificates a credible proxy for tracking or allocating generator-specific indirect emission factors for purchased electricity.
To put this question more precisely: Am I purchasing and/or consuming electricity from renewable energy generation when I purchase and retire a REC or GO?
Physically, the answer is clearly no. RECs, GOs, or any other contractual arrangements intended to claim “green power” procurement are, at best, an invented proxy for using renewable energy. The question, then, is do these certificates or other contractual instruments provide a technically credible proxy for GHG and other environmental accounting applications, such as conveying an exclusive claim to a generator-specific indirect emission factor (hint, the answer is no).
First, even if you are buying RECs or GOs, for every MWh of your electricity consumption, you are most likely dependent on the availability of other non-renewable generation resources (e.g., fossil and nuclear) to provide your reliable and continuous electricity supply.
Second, these certificates record each MWh of electricity generated (i.e., injected to the shared transmission and distribution grid) from participating renewable generators. But, there is a difference between the quantity of electricity generated and the quantity consumed on a grid. The difference is losses, due mainly to transmission and distribution (e.g., typically 5 to 10% in the USA and Europe, although it can be much larger in some countries). For example, the generation associated with a record of 100 RECs in a certificate registry would correctly only correspond to 90 MWh of electrical load (i.e., with a 10% loss factor).