Ocean News

Scientists have discovered a sea of fresh water under the ocean

Thousands of years ago, glaciers covered much of the planet. Oceans receded as water froze in massive sheets of ice blanketing the North American continent. As the ice age ended, glaciers melted. Massive river deltas flowed out across the continental shelf. The oceans rose, and fresh water was trapped in sediments below the waves. Discovered while drilling for oil offshore in the 1970s, scientists thought these “isolated” pockets of fresh water were a curiosity. They may instead prove to be a parched world’s newest source of fresh water....

It turns out the subterranean pools stretch for at least 50 miles off the US Atlantic coast, containing vast stores of low-salinity groundwater, about twice the volume of Lake Ontario. The deposits begin about 600 ft (183 m) below the seafloor and stretch for hundreds of miles. That rivals the size of even the largest terrestrial aquifers....

 

Part of the Pacific Ocean Is Not Warming as Expected. Why?

...Climate models of global warming — computerized simulations of what various parts of the earth are expected to do in reaction to rising greenhouse gases — say that the equatorial cold tongue, along with other regions, should have started warming decades ago, and should still be warming now. But the cold tongue has remained stubbornly cold....

In a new paper in the journal Nature Climate Change, [Richard Seager] and colleagues use simplified models that isolate the fundamental dynamics of the tropical Pacific atmosphere-ocean system. These, they say, comport with the cold tongue’s actual behavior — and show that it is consistent with rising greenhouse gases....



...If, instead, we are right and the cold tongue will not warm as much, then drying in southwest North America, subtropical South America and east Africa could be more severe than the complex models project. At the same time, equatorial South America and the Sahel might see wetter conditions....

 

Do airplane contrails add to climate change? Yes, and the problem is about to get worse.

 

Breaching a “carbon threshold” could lead to mass extinction

Daniel Rothman, professor of geophysics and co-director of the Lorenz Center in MIT’s Department of Earth, Atmospheric and Planetary Sciences, has found that when the rate at which carbon dioxide enters the oceans pushes past a certain threshold — whether as the result of a sudden burst or a slow, steady influx — the Earth may respond with a runaway cascade of chemical feedbacks, leading to extreme ocean acidification that dramatically amplifies the effects of the original trigger....

But Rothman says [the smaller the trigger, the smaller the environmental fallout] is not the case. It didn’t matter what initially caused the events; for roughly half the disruptions in his database, once they were set in motion, the rate at which carbon increased was essentially the same. Their characteristic rate is likely a property of the carbon cycle itself — not the triggers, because different triggers would operate at different rates.....

According to Rothman, today we are “at the precipice of excitation,” and if it occurs, the resulting spike — as evidenced through ocean acidification, species die-offs, and more — is likely to be similar to past global catastrophes.....

 

Climate change could cost the U.S. up to 10.5 percent of its GDP by 2100, study finds

Long-Term Macroeconomic Effects of Climate Change: A Cross-Country Analysis https://www.nber.org/papers/w26167

 

The World’s Oceans Are in Danger, Major Climate Change Report Warns | NY Times

for full report see:
Special Report on the Ocean and Cryosphere in a Changing Climate | IPCC

 

Ocean acidification can cause mass extinctions, fossils reveal

The research was published in the journal Proceedings of the National Academy of Sciences.

 

The missing economic risks in assessments of climate change impacts | London School of Economics and Political Science

Download full report

In order to make well-informed decisions on climate change action, leaders need to understand clearly the nature and magnitude of the risks to lives and livelihoods that are being created by climate change. Unfortunately, much of the technical advice and recommendations about these risks incorporate assessments of the economic implications that omit or underplay the largest potential impacts of climate change.

This policy insight seeks to identify and draw attention to these missing and under-represented risks. The authors also discuss how populations might fare in light of their potential to adapt in the face of these risks. When the risks are taken into account, the case for strong, deliberate and urgent action to reduce greenhouse gas emissions becomes even more compelling.

Summary points

• Economic assessments of the potential future risks of climate change have been omitting or grossly underestimating many of the most serious consequences for lives and livelihoods because these risks are difficult to quantify precisely and lie outside of human experience.
• Political and business leaders need to understand the scale of these ‘missing risks’ because they could have drastic and potentially catastrophic impacts on citizens, communities and companies.
• Scientists are growing in confidence about the evidence for the largest potential impacts of climate change and the rising probability that major thresholds in the Earth’s climate system will be breached as global mean surface temperature rises, particularly if warming exceeds 2°C above the pre-industrial level. These impacts include:
  • Destabilisation of ice sheets and glaciers and consequent sea level rise
  • Stronger tropical cyclones
  • Extreme heat impacts
  • More frequent and intense floods and droughts
  • Disruptions to oceanic and atmospheric circulation
  • Destruction of biodiversity and collapse of ecosystems
• Many of these impacts will grow and occur concurrently across the world as global temperature climbs.
• Some of these impacts involve thresholds in the climate system beyond which major impacts accelerate, or become irreversible and unstoppable.
• When a threshold is breached, it might cause one or more other thresholds to be exceeded as well, leading to a cascade of impacts.
• Many of these impacts could exceed the capacity of human populations to adapt, and would significantly affect and disrupt the lives and livelihoods of hundreds of millions, if not billions, of people worldwide.
• These impacts would also undermine economic growth and development, exacerbate poverty and destabilise communities.
• Economic assessments fail to take account of the potential for large concurrent impacts across the world that would cause mass migration, displacement and conflict, with huge loss of life.
• Economic assessments that are expressed solely in terms of effects on output (e.g. gross domestic product), or that only extrapolate from past experience, or that use inappropriate discounting, do not provide a clear indication of the potential risks to lives and livelihoods.
• It is likely that there are additional risks that we are not yet anticipating simply because scientists have not yet detected their possibility, as we have entered a period of climate change that is unprecedented in human history.
• Some advances are being made in improving economic assessments of climate change impacts but much more progress is required if assessments are to offer reliable guidance for political and business leaders on the biggest risks.
• The lack of firm quantifications is not a reason to ignore these risks, and when the missing risks are taken into account, the case for strong and urgent action to reduce greenhouse gas emissions becomes even more compelling.

 

Rising Seas Will Erase More Cities by 2050, New Research Shows

The authors of a paper published in Nature Communications developed a more accurate way of calculating land elevation based on satellite readings, a standard way of estimating the effects of sea level rise over large areas, and found that the previous numbers were far too optimistic. The new research shows that some 150 million people are now living on land that will be below the high-tide line by midcentury.

 

Ocean Warming Is Accelerating Faster Than Thought, New Research Finds

 

UN: The world has backed itself into a treacherous corner on climate change.

The world is further off course than ever from meeting the goals of the Paris climate agreement and averting climate catastrophe as the divide between countries’ pledges and actions continues to grow.

This grim assessment comes from the latest United Nations Emissions Gap Report published Tuesday. “Gap” refers to the difference between what countries have committed to do to limit climate change and what they actually need to do to meet greenhouse gas targets.

The findings aren’t surprising, given that global greenhouse gas emissions have reached all-time highs in recent years. But they are still alarming. Since the first gap report was published in 2010, carbon dioxide emissions have risen 11 percent.

The IPCC has also warned that the changes in the climate already underway are leading to unprecedented and irreversible shifts in lands, oceans, and the frozen parts of the planet, making them hostile to life.

 

Florida Keys Deliver a Hard Message: As Seas Rise, Some Places Can’t Be Saved

 

Climate models have accurately predicted global heating, study finds

Climate models have accurately predicted global heating for the past 50 years, a study has found.

The findings confirm that since as early as 1970, climate scientists have had a solid fundamental understanding of the Earth’s climate system and the ability to project how it will respond to continued increases in the greenhouse effect. Since climate models have accurately anticipated global temperature changes so far, we can expect projections of future warming to be reliable as well.

 

Climate contrarian uncovers scientific error, upends major ocean warming study

Researchers with UC San Diego’s Scripps Institution of Oceanography and Princeton University recently walked back scientific findings published last month that showed oceans have been heating up dramatically faster than previously thought as a result of climate change.

Co-author Ralph Keeling, climate scientist at the Scripps Institution of Oceanography, took full blame and thanked Lewis for alerting him to the mistake.

“When we were confronted with his insight it became immediately clear there was an issue there,” he said. “We’re grateful to have it be pointed out quickly so that we could correct it quickly.”

Keeling said they have since redone the calculations, finding the ocean is still likely warmer than the estimate used by the IPCC. However, that increase in heat has a larger range of probability than initially thought — between 10 percent and 70 percent, as other studies have already found.

 

World’s Oceans Are Losing Oxygen Rapidly, Study Finds

A report issued at the annual global climate talks in Madrid has concluded that oxygen levels in the world’s oceans declined by roughly 2 percent between 1960 and 2010. The decline, called deoxygenation, is largely attributed to climate change, although other human activities are contributing to the problem. One example is so-called nutrient runoff, when too many nutrients from fertilizers used on farms and lawns wash into waterways.

“The ocean is not uniformly populated with oxygen,” he added. One study in the journal Science, for example, found that water in some parts of the tropics had experienced a 40 to 50 percent reduction in oxygen.