Oceans at risk from global warming

Stopping global heating will stop additional ocean warming which, in turn, will slow or stop ice sheet and glacial melt. It will ensure that coastal communities remain habitable.

Oceans provide 50% of our oxygen, produce important medications, act as a major carbon sink, and coastal communities rely on marine life as one of their main sources of food. We are interconnected with the ocean, and need to consider the health and survival of the ocean as an extension of our own health and survival.

Read a roundup of the headlines:

“Global warming and extensive overfishing have damaged ocean ecosystems well beyond recognition from only a few decades ago. Still, on its own accord, the ocean stood tall for over 3 billion years. But, alas, in less than one human lifetime it is teetering like never before, and credible studies claim the world’s oceans could be devoid of life within only three decades. This is one of the most troubling transformations of all time, nothing compares to it, absolutely nothing!

The ocean heat bomb is all about the impact of global warming and overfishing, neither of which is high enough on to-do lists of countries to help sustain ecosystems. It should be noted that Wall Street’s embrace of going green for a profit won’t come close (not enough scale soon enough) to solving the global warming problem, but there’s plenty of green to be made.”

Pressenza, The Ocean Heat Bomb Ignites

“The ocean has long taken the brunt of the impacts of human-made global warming, says UN Climate Change. As the planet’s greatest carbon sink, the ocean absorbs excess heat and energy released from rising greenhouse gas emissions trapped in the Earth’s system. Today, the ocean has absorbed about 90 percent of the heat generated by rising emissions. 

As the excessive heat and energy warms the ocean, the change in temperature leads to unparalleled cascading effects, including ice-melting, sea-level rise, marine heatwaves, and ocean acidification. 

These changes ultimately cause a lasting impact on marine biodiversity, and the lives and livelihoods of coastal communities and beyond - including around 680 million people living in low-lying coastal areas, almost 2 billion who live in half of the world’s megacities that are coastal, nearly half of the world’s population (3.3 billion) that depends on fish for protein, and almost 60 million people who work in fisheries and the aquaculture sector worldwide.”

United Nations, How is climate change impacting the world’s ocean

“But a warmer, more acidic ocean does us no favors when it comes to maintaining its role as one of the biggest carbon sinks on our planet. The ocean stores 50 times more carbon than the atmosphere, and 20 times more than land plants and soil combined, Buesseler said. If these climate trends persist, it’s not clear whether its title as carbon champion will be sustainable.”

PBS, When it comes to sucking up carbon emissions, ‘the ocean has been forgiving.’ That might not last

“Scientists are finding hidden climate time bombs—vast reservoirs of carbon dioxide and methane—scattered under the seafloor across the planet.

And the fuses are burning.

Caps of frozen CO2 or methane, called hydrates, contain the potent greenhouse gases, keeping them from escaping into the ocean and atmosphere. But the ocean is warming as carbon emissions continue to rise, and scientists say the temperature of the seawater surrounding some hydrate caps is within a few degrees of dissolving them.

That could be very, very bad. Carbon dioxide is the most common greenhouse gas, responsible for about three-quarters of emissions. It can remain in the atmosphere for thousands of years. Methane, the main component of natural gas, doesn't stay in the atmosphere as long as CO2—about 12 years—but it is at least 84 times more potent over two decades.”

National Geographic, Huge amounts of greenhouse gases lurk in the oceans, and could make warming far worse

“The ocean generates 50 percent of the oxygen we need, absorbs 25 percent of all carbon dioxide emissions and captures 90 percent of the excess heat generated by these emissions. It is not just ‘the lungs of the planet’ but also its largest ‘carbon sink’ – a vital buffer against the impacts of climate change.

The ocean is central to reducing global greenhouse gas emissions and stabilizing the Earth’s climate.

However, increasing greenhouse gas emissions have affected the health of the ocean – warming and acidifying seawater – causing detrimental changes to life under water and on land, and reducing the ocean’s ability to absorb carbon dioxide and safeguard life on the planet.”

United Nations, The ocean – the world’s greatest ally against climate change

“In the past decade ocean oxygen levels have taken a dive—an alarming trend that is linked to climate change, says Andreas Oschlies, an oceanographer at the Helmholtz Center for Ocean Research Kiel in Germany, whose team tracks ocean oxygen levelsworldwide. “We were surprised by the intensity of the changes we saw, how rapidly oxygen is going down in the ocean and how large the effects on marine ecosystems are,” he says.

It is no surprise to scientists that warming oceans are losing oxygen, but the scale of the dip calls for urgent attention, Oschlies says. Oxygen levels in some tropical regions have dropped by a startling 40 percent in the last 50 years, some recent studies reveal. Levels have dropped more subtly elsewhere, with an average loss of 2 percent globally...

As oxygen-rich regions become scarcer, current fish habitats will also shrink and force economically important species—such as tuna, which globally generate an estimated $42 billion annually—into new ranges. In the northeastern tropical Atlantic researchers have found habitat for tuna as well as billfish fisheries shrank by 15 percent from 1960 to 2010 (pdf) due to oxygen loss.

Coastline fisheries can also face the added pressure of agricultural runoff fertilizing algal blooms that consume copious oxygen as they decay—as has long been the case in the Gulf of Mexico near the mouth of the Mississippi River.“

Scientific American, The Ocean Is Running Out of Breath, Scientists Warn