baseline concentration

Other amendments, including Amendments 38 and 39, concerning the reference to baseline concentrations and the special assessment of trends in relation to point sources of pollution, are accepted by the Commission.

A 2005 Government report singled out the Causeway Bay Typhoon Shelter as having "exceptionally high levels" of tributyltin, exceeding 1000 times the baseline concentration measured in the East Lamma Channel.

Both sets of data suggest that a sudden climate threshold or tipping point occurs at about four times the Earth's mean carbon dioxide levels relative to the baseline concentrations of about 280 ppmv that existed circa 1750.