SPUR has written to the Bay Area Air Quality Management District (BAAQMD) asking that it clarify, as it did in 2010, that the proposed updated CEQA thresholds of significance for greenhouse gas (GHG) emissions, if adopted, will apply prospectively only. A clear effective date for the updated guidelines will particularly provide certainty and support local governments’ efforts to address the state’s housing shortage. First adopted by BAAQMD in 2010, these thresholds are designed to establish the level at which the Air District finds that air pollution and GHG emissions would cause significant environmental impacts under CEQA.