Oceans and Global Warming

 

                       The Ocean Water Garden Overheats

Here in the Midwest our closest tie to the ocean is probably the Friday Night Fish Fry.

130 columns ago I wrote about coral reefs, warning of their demise due to global warming and carbonic acidification. This is caused primarily by the excess CO2 we push into the air.

There are more reasons we should pay attention to oceans. First off, much of the world depends on healthy oceans for food, especially protein. Second, many people make a living fishing and taking people out to fish or dive. Third, oceanside cities and seaports are built to operate where the sea level is now.  Fourth, oceans, via evaporation, create much of our rain and mega-rain events. Fifth, North America’s stable weather depends on an ice-covered Arctic Ocean. And, last but not least, the organisms in the ocean free up oxygen, a whopping 70% of what we need.

The oceans are massive and make up 70.9% of the earth’s surface compared with North America’s 4.8%. The oceans suck up 93% of the excess heat trapped by our fossil fuel pollution. As we might expect, they are warming rapidly. They shield us from excess heat, but their effectiveness diminishes as they warm. Here is what is happening now.

The coral reefs continue to be attacked by CO2. Coral is sensitive to temperature changes and carbonic acidification. As a result, they are dying. Their brilliant colors “bleached” dead, ghosts of their once brilliant selves.

Coral makes up less than 1% of the ocean floor yet it is vital to 25% of the species in the ocean. About one billion people depend on the coral habitat for food and a living. In an already hungry world, the loss of coral would be devastating.

Like rich forests on land the oceans have forests of kelp. These too are rich habitat for sea life. These too are suffering. It appears the giant kelp forests are our next victims. The giant kelp forests south of Australia’s Tasmania are all but gone and California’s are disappearing.

Oceans do not heat evenly. The massive 1000 square mile expanse of hot water in the Pacific was named by the ocean biologists “The Blob” after the sci-fi horror movie by the same name. The heat Blob drives fish away from their normal habitat. The most visible sign of this is the massive die-offs of marine mammals and seabirds. They are simply unable to fly or swim far enough to find food for their young.

Fish, or I should be more specific, adult fish are being documented far from their normal ranges escaping the heat. This ability to migrate to healthier waters should not be taken as particularly good news. A new study of 700 fish species found while adult fish can move and even tolerate temperature changes, their eggs and young fish cannot. Of the 700 fish species studied, 60% will not survive in their current home ranges by 2100. To add one more uncomfortable fact, the reason the heat is so lethal is it makes it impossible for fish in their early stages of life to breathe. Cold water holds more oxygen.  Our freshwater fish, those that flourish in our local waters, like trout and walleye, face similar challenges.              

A forest we do not have here are the mangrove forests. Mangroves are specially adapted trees that live in the brackish water fringing of our oceans. Like coral and kelp, they are breeding grounds for marine species. Like out terrestrial forests they, when healthy, sequester vast amounts of carbon.

Mangrove forest today are toughing it out. They can only survive if sea-level rise remains below 7mm per year. Today sea level rise is 3.4mm per year. If we stick to our status quo pollution emissions we could easily be at 5 to 10 mm rise per year by 2100.

The arctic, as you know, is warming faster than any other place on earth. There are a lot of troubling side effects that come with this warming.  The one we usually hear about is loss of sea-ice. This makes it tough for the polar bear, seal, and Eskimo to make a living.

While I worry about their plight, theirs is not my main concern. Plentiful Arctic Ocean ice is essential for a stable climate right here. The volume of Arctic Sea Ice is already down 75% from the 1980s average. Unfortunately, there lurks at the bottom of the Arctic Sea, another heat blob formed from growing warm salty Atlantic waters. This blob usually sits 450 feet below the surface safely separated from the ice on top. Now, it is rising and is within 240 feet. It holds enough heat to melt all the Arctic ice 3 times over.

We know so little about the oceans. We have mapped 20% of it. There are at least 230,000 documented fellow earthling species living in the watery realm. Most species are not even documented and scientists estimate there could be 2 million.

If we do nothing, we can count on watching sea creatures die first. Fossil records document ocean life is more sensitive to rises in CO2 and temperature than terrestrial life.

I had the privilege of exploring a tiny sliver of the ocean via snorkel, kayak, and ship. There is something humbling and awe inspiring seeing a whale three times longer than your kayak elegantly cruise by.

Or, to sail through, for fifteen minutes, a pod of spinner dolphin so numerous you can see nothing but dancing dolphin from horizon to horizon.

Or, to snorkel down next to a cuttlefish feeding on a coral reef. The two of us spending time hanging out eye to eye; each wondering what the other’s role was in this close encounter.

I still try to come to grips with my role in our beautiful world of grand wonder. We are God’s Creatures in God’s land and water garden. Of all the creatures on the garden planet only one is tasked with tending and caring for the garden, His Garden. That is us.

        Abbreviated reference list:                                                                            “Marine Heat Waves linked to Human Caused Warming”                                     Inside Science News, the American Physical Society   25SEP 2020.                                                                                                                                                             “Sea level rise could drown mangroves”  Science News   4July.                         “When do fish succumb to heat?”  Science   3July.                                      “New feedbacks speed the demise of Arctic Sea Ice”  Science   4AUG.                “Animals go far to flee ocean heat waves”   Science News  12Sep.                       “Marine food web destabilized”  Science   14AUG.                                            “Blue Carbon from the past forecasts the future”  Science   5JUN.                   Bible, Genesis 2:15                                                                                                      Documentary: “Chasing Coral”  Netflix