The debate over reducing greenhouse gas emissions — through renewable energy, cap-and-trade programs, more fuel-efficient cars — often comes down to the cost. Is the price tag worth the effort to combat climate change?

When it comes to the world's oceans, the answer should be an unequivocal yes.

The evidence is mounting that the effects of too much carbon dioxide in the atmosphere can cause significant damage to coral reefs and marine life, particularly shellfish.

The oceans already absorb as much as one-third of atmospheric CO2, serving as a critical buffer against climate change. Pumping more CO2 into the atmosphere — which humans have been doing robustly since the Industrial Revolution — causes seawater to become more acidic, stunting the ability of corals, larvae and calcifying marine life to grow.

The long-term consequences are not well understood; ocean acidification is a young field of study. Nonetheless, observations show that ocean acidity has increased by 30 percent since the beginning of the Industrial Revolution. And combined with another greenhouse gas effect — warmer ocean temperatures that can cause coral bleaching — scientists warn of the possibility of major disruptions in the marine food chain.

Coral ecosystems are nurseries and feeding grounds for many marine species, including those with commercial value. If coral erosion outpaces growth, and reefs start dying and disappearing, the result could be catastrophic, and not only for the environment.

Commercial fisheries and societies whose economies depend on the sea — including Hawai'i's tourism industry —could suffer billions of dollars in losses. Protection from shoreline storm surges that reefs provide could also disappear.

Beyond the economic consequences, protecting a vibrant ocean ecosystem should be cause enough to push harder for energy alternatives. After all, protecting our ocean environment for future generations is our fundamental responsibility.