In anticipation of the final season of “Game of Thrones,” social media were abuzz with speculation that the dreaded white walkers were a parable of coming climate disruption. “Winter is here!” was the ominous warning. Fortunately, humanity was saved instantly by a single, well-placed stab by Arya Stark.

Reality is much more challenging. Summer is here, and as evidenced by the record-breaking June temperatures Hawaii suffered, the scientific community is predicting severe coral bleaching caused by unusually warm sea temperatures, happening by the beginning of fall, when the ocean is typically at its warmest.

Coral bleaching occurs when corals lose symbiotic microbes from their tissues due to high ocean temperatures and other stressors. The microbes feed the corals and produce their colors. With their loss, the coral starves and turns white as snow, hence the somewhat misleading term “bleaching.”

Severely bleached corals die and become overgrown by seaweeds. The Southern Hemisphere kindred analog of the Hawaiian archipelago, French Polynesia, has already suffered tremendous coral bleaching and death this year. As the sun now dominates the Northern Hemisphere, it is Hawaii’s turn. Summer is here and the white walkers of coral bleaching are coming!

The recent mass coral bleaching of 2014-2015 killed about half of the affected corals in the main Hawaiian Islands. If the coral dies, the reef dies. No reef, no coastal protection from sea level rise and worsening storms, no undersea beauty to lift the spirit (or to attract tourists), no fish to eat, no new medicines from the cornucopia of reef species.

What can Hawaii do?

Courtesy Luiz Rocha

Most importantly, we can stop dragging our feet and truly become a national showcase for addressing climate disruption. So far, there has been far more talk than action, politicians kicking the can down the road so they don’t have to make any difficult decisions that would anger local business interests.

The scientific community has made it abundantly clear that time is of the essence to reverse out-of-control global warming. The time is now to switch fully to solar and wind power, to reforest our islands, and to grow more food locally! These actions will reduce the carbon footprint of Hawaii, as well as improve our collective lives.

Regarding our reefs, dead corals can recover only where there are plenty of seaweed-eating fishes and sea urchins present to keep reef surfaces clean so new corals can settle and grow. New corals start life on the seafloor as a single coral polyp, the same polyp that begins the Kumulipo, the Hawaiian creation chant. Uhu (parrotfishes) are especially important herbivores, yet are critically overfished.

“Save the uhu!” is a fitting mantra and action for helping our reefs recover after coral bleaching.

Here is another: “Malama i ke kai, a malama ke kai ia oe.” (“Care for the ocean, and the ocean will care for you.)

Arya Stark cannot save us from the coming ocean white walkers. It’s up to us.