Page 4.F-2       OSEC-190 [See page 5-331 for the original comment] REVISE the last paragraph as follows.

Global warming impacts in California may include, but are not limited to, loss in snow pack, sea level rise, more extreme heat days per year, more high ozone days, more large forest fires, and more drought years. Secondary effects are likely to include the displacement of thousands of coastal businesses and residences, impacts on agriculture, changes in disease vectors, and changes in habitat and biodiversity. As the California Air Resources Board (CARB) Climate Change Scoping Plan noted, the legislature in enacting Assembly Bill (AB) 32 found that global warming would cause detrimental effects to some of the state’s largest industries, including agriculture, winemaking, tourism, skiing, commercial and recreational fishing, forestry, and the adequacy of electrical power generation. The Climate Change Scoping Plan states as follows (CARB, 2011): “The impacts of global warming are already being felt in California. The Sierra snowpack, an important source of water supply for the state, has shrunk 10 percent in the last 100 years. It is expected to continue to decrease by as much as 25 percent by 2050. World-wide changes are causing sea levels to rise – about eight inches of increase has been recorded at the Golden Gate Bridge over the past 100 years – threatening low coastal areas with inundation and serious damage from storms.”

Page 4.F-3       OSEC-191 [See page 5-331 for the original comment] ADD the following text after the first full paragraph:

Uptake of anthropogenic CO2 results in gradual acidification of the ocean. The pH of surface seawater has decreased by 0.1 since the beginning of the industrial era, corresponding to a 26% increase in hydrogen ion concentration. The observed pH trends range between a –0.0014 and –0.0024 reduction per year in surface waters. In the ocean interior, natural physical and biological processes, as well as uptake of anthropogenic CO2, can cause changes in pH over decadal and longer time scales (Rhein et al, 2013).

While more than half of the CO2 emitted is currently removed from the atmosphere within a century, some fraction (about 20%) of emitted CO2 remains in the atmosphere for many millennia. Because of slow removal processes, atmospheric CO2 will continue to increase in the long term even if its emission is substantially reduced from present levels. Methane (CH4) is removed by chemical processes in the atmosphere, while nitrous oxide (N2O) and some halocarbons are destroyed in the upper atmosphere by solar radiation. These processes each operate at different time scales ranging from years to millennia. A measure for this is the lifetime of a gas in the atmosphere, defined as the time it takes for a perturbation to be reduced to 37% of its initial amount. While for CH4, N2O, and other trace