…The work shows that temperature rises measured over recent decades do not fully reflect the global warming already in the pipeline and that the ultimate heating of the planet could be even worse than feared.
….how much global temperatures rise for a certain level of carbon emissions is called climate sensitivity and is seen as the single most important measure of climate change. Computer models have long indicated a high level of sensitivity, up to 4.5C for a doubling of CO2 in the atmosphere.… the new work, using both models and paleoclimate data from warming periods in the Earth’s past, shows that the historical temperature measurements do not reveal the slow heating of the planet’s oceans that takes place for decades or centuries after CO2 has been added to the atmosphere.
…The new research, published in the journal Science Advances, has ended that. “The worrisome part is that all the models show there is an amplification of the amount of warming in the future,” he said. The situation might be even worse, as Proistosescu’s work shows climate sensitivity could be as high as 6C.
….“The models simulate a warming pattern like today’s, but indicate that strong feedbacks kick in when the Southern Ocean and Eastern Equatorial Pacific eventually warm, leading to higher overall temperatures than would simply be extrapolated from the warming seen to date,” said [co-author] Peter Huybers…“But there is no perfect analogue for the changes that are coming.”
….The most important measurement of global warming is in the oceans. In fact, “global warming” is really “ocean warming.” If you are going to measure the changing climate of the oceans, you need to have many sensors spread out across the globe that take measurements from the ocean surface to the very depths of the waters. Importantly, you need to have measurements that span decades so a long-term trend can be established.
These difficulties are tackled by oceanographers, and a significant advancement was presented in a paper just published in the journal Climate Dynamics. ….We found that regardless of whose data was used or where the data was gathered, the oceans are warming.
…In the study, we looked at the different ways that three groups make decisions about mapping, bias, and climatology. We not only asked how much the oceans are warming, but how the warming differs for various areas (ocean basins) and various depths. We found that each ocean basin has warmed significantly. Despite this fact, there are some differences amongst the three groups. For instance, in the 300-700 meter oceans depths in the Pacific and Southern oceans, significant differences are exhibited amongst the tree groups. That said, the central fact is that regardless of how you measure, who does the measurements, when or where the measurements are taken, we are warming….. it will be important that we keep high-quality temperature sensors positioned throughout the oceans so in the future we will be able to predict where our climate is headed. We say in science that a measurement not made is a measurement lost forever. And there are no more important measurements than of heating of the oceans.
Inconsistent global/basin ocean heat content (OHC) changes were found in different ocean subsurface temperature analyses, especially in recent studies related to the slowdown in global surface temperature rise. This finding challenges the reliability of the ocean subsurface temperature analyses and motivates a more comprehensive inter-comparison between the analyses. Here we compare the OHC changes in three ocean analyses (Ishii, EN4 and IAP) to investigate the uncertainty in OHC in four major ocean basins from decadal to multi-decadal scales. First, all products show an increase of OHC since 1970 in each ocean basin revealing a robust warming, although the warming rates are not identical. The geographical patterns, the key modes and the vertical structure of OHC changes are consistent among the three datasets, implying that the main OHC variabilities can be robustly represented. However, large discrepancies are found in the percentage of basinal ocean heating related to the global ocean, with the largest differences in the Pacific and Southern Ocean. Meanwhile, we find a large discrepancy of ocean heat storage in different layers, especially within 300–700 m in the Pacific and Southern Oceans. Furthermore, the near surface analysis of Ishii and IAP are consistent with sea surface temperature (SST) products, but EN4 is found to underestimate the long-term trend. Compared with ocean heat storage derived from the atmospheric budget equation, all products show consistent seasonal cycles of OHC in the upper 1500 m especially during 2008 to 2012. Overall, our analyses further the understanding of the observed OHC variations, and we recommend a careful quantification of errors in the ocean analyses.
Highly protected marine reserves can help mitigate against the impacts of climate change, a study by a team of international scientists has concluded….The study….evaluated existing peer reviewed studies on the impact of marine reserves around the world.Currently, only 3.5 per cent of the ocean has been set aside for protection with just 1.6 per cent fully protected from exploitation. International groups are working to raise the total to 10 per cent by 2020, while delegates to the International Union for the Conservation of Nature’s 2016 World Conservation Congress agreed that at least 30 per cent should be protected by 2030.
Scientists say Marine Reserves and Marine Protected Areas (MPAs):
Protect coasts from sea-level rise, storms and other extreme weather events
Help offset climate-change induced declines in ocean and fisheries productivity
Provide refuges for species as they adjust their ranges to changing conditions
Can help combat acidification…
Callum M. Roberts, Bethan C. O’Leary, Douglas J. McCauley, Philippe Maurice Cury, Carlos M. Duarte, Jane Lubchenco, Daniel Pauly, Andrea Sáenz-Arroyo, Ussif Rashid Sumaila, Rod W. Wilson, Boris Worm, and Juan Carlos Castilla. Marine reserves can mitigate and promote adaptation to climate change. PNAS, June 2017 DOI: 10.1073/pnas.1701262114
…A change in temperature variability leads to more frequent warmer and colder events while a change in the temperature mean increases the occurrence of warmer events but decreases the occurrence of colder events. The researchers found that changes in the variation of ocean temperatures had a threefold effect on the growth rate of the albatross population compared to changes in just mean ocean temperature.Increasing variation of ocean temperatures — temperatures that range well below or above the optimum for the species — leads to population decline, while increasing the mean (average) of ocean temperatures result in population increase.
… In other words, the effect of extreme events can be buffered when species live in cooler than optimal environments, providing a kind of “climate safety margin” for those species.
“In this case, the historical mean (or average) of sea surface temperatures was lower than the optimal temperature for this species,” explains Jenouvrier. “If the mean temperature warms, these albatrosses will experience temperatures that will be more often at or near the optimum range for the species, so these changes in mean will buffer the negative effects of the extreme warming events.” However, even for those species that do experience a buffering effect from the climate safety margin, it’s likely to be only temporary as future temperatures continue to rise beyond their optimal temperature range, she adds….
Martijn van de Pol, Stéphanie Jenouvrier, Johannes H. C. Cornelissen, Marcel E. Visser. Behavioural, ecological and evolutionary responses to extreme climatic events: challenges and directions. Philosophical Transactions of the Royal Society B: Biological Sciences, 2017; 372 (1723): 20160134 DOI: 10.1098/rstb.2016.0134.
Experiments suggest long term changes to the global carbon cycle are underway
Biological impacts of seawater pH have implications for the use of foraminifera as paleoceanographic indicators.
May 25, 2017 University of California – Davis Bodega Marine Lab ScienceDaily
… For the study, published in the journal Scientific Reports, scientists raised foraminifera — single-celled organisms about the size of a grain of sand — at the UC Davis Bodega Marine Laboratory under future, high CO2 conditions. These tiny organisms, commonly called “forams,” are ubiquitous in marine environments and play a key role in food webs and the ocean carbon cycle….UC Davis scientists found that under high CO2, or more acidic, conditions, the foraminifera had trouble building their shells and making spines, an important feature of their shells….[and] showed signs of physiological stress, reducing their metabolism and slowing their respiration to undetectable levels.
This is the first study of its kind to show the combined impact of shell building, spine repair, and physiological stress in foraminifera under high CO2 conditions. The study suggests that stressed and impaired foraminifera could indicate a larger scale disruption of carbon cycling in the ocean….
…As a marine calcifier, foraminifera use calcium carbonate to build their shells, a process that plays an integral part in balancing the carbon cycle. Normally, healthy foraminifera calcify their shells and sink to the ocean floor after they die, taking the calcite with them. This moves alkalinity, which helps neutralize acidity, to the seafloor. When foraminifera calcify less, their ability to neutralize acidity also lessens, making the deep ocean more acidic. …”That acidified water from the deep will rise again. If we do something that acidifies the deep ocean, that affects atmospheric and ocean carbon dioxide concentrations on time scales of thousands of years.” [Catherine] Davis said the geologic record shows that such imbalances have occurred in the world’s oceans before, but only during times of major change. “This points to one of the longer time-scale effects of anthropogenic climate change that we don’t understand yet,” Davis said.
…strong winds periodically push nutrient-rich water from the deep ocean up to the surface– Upwelling supports some of the planet’s most productive fisheries and ecosystems. But additional anthropogenic, or human-caused, CO2 in the system is expected to impact fisheries and coastal ecosystems…. UC Davis’ Bodega Marine Laboratory in Northern California is near one of the world’s most intense coastal upwelling areas. At times, it experiences conditions most of the ocean isn’t expected to experience for decades or hundreds of years.
“Seasonal upwelling means that we have an opportunity to study organisms in high CO2, acidic waters today — a window into how the ocean may look more often in the future,” said co-author Tessa Hill, an associate professor in earth and planetary sciences at UC Davis. “We might have expected that a species of foraminifera well-adapted to Northern California wouldn’t respond negatively to high CO2 conditions, but that expectation was wrong. This study provides insight into how an important marine calcifier may respond to future conditions, and send ripple effects through food webs and carbon cycling.”
Catherine V. Davis, Emily B. Rivest, Tessa M. Hill, Brian Gaylord, Ann D. Russell, Eric Sanford. Ocean acidification compromises a planktic calcifier with implications for global carbon cycling. Scientific Reports, 2017; 7 (1) DOI: 10.1038/s41598-017-01530-9
Abstract: ….We cultured a globally important calcifying marine plankter (the foraminifer, Globigerina bulloides) under an ecologically relevant range of seawater pH (7.5 to 8.3 total scale). Multiple metrics of calcification and physiological performance varied with pH. At pH > 8.0, increased calcification occurred without a concomitant rise in respiration rates. However, as pH declined from 8.0 to 7.5, calcification and oxygen consumption both decreased, suggesting a reduced ability to precipitate shell material accompanied by metabolic depression. Repair of spines, important for both buoyancy and feeding, was also reduced at pH < 7.7. The dependence of calcification, respiration, and spine repair on seawater pH suggests that foraminifera will likely be challenged by future ocean conditions. Furthermore, the nature of these effects has the potential to actuate changes in vertical transport of organic and inorganic carbon, perturbing feedbacks to regional and global marine carbon cycling. The biological impacts of seawater pH have additional, important implications for the use of foraminifera as paleoceanographic indicators.
Ocean currents affect how climate change impacts movements of species to cooler regions. A new study provides novel insight into how species’ distributions change from the interaction between climate change and ocean currents….
They found that species expanded their range faster and kept track of climate better when ocean currents matched the direction of warming. “We were expecting ocean currents to be most influential at the leading ‘cold’ edge of a species’ range, where warming represents an opportunity for the expansion of its range,” comments García Molinos. “In those situations it’s a little bit like a conveyor belt at an airport terminal. If you want to get to your boarding gate and you walk with the belt, you approach the gate faster than if you just stand on it passively. If you take the belt that goes in the opposite direction you will need to walk fast or even run to make progress.”
However, matching ocean currents and warming unexpectedly slowed down range contractions, or the speed of withdrawal at the “warm” edges. “This was somehow a surprise because we were expecting contraction rates to be mainly driven by the rate of warming,” says co-author Prof. Michael T. Burrows. ….”Our study suggests how directional forces such as ocean or air currents can influence the coupling between climate change and biogeographical shifts. Our simple metric can be used to improve predictions of distribution shifts and help explain differences in expansion and contraction rates among species,” concludes García Molinos.
J. García Molinos, M. T. Burrows, E. S. Poloczanska. Ocean currents modify the coupling between climate change and biogeographical shifts. Scientific Reports, 2017; 7 (1) DOI: 10.1038/s41598-017-01309-y
Before 1990, oceans were rising at about 1.1 millimeters per year, or just 0.43 inches per decade. From 1993 through 2012, though, it finds that they rose at 3.1 millimeters per year, or 1.22 inches per decade.
A new scientific analysis finds that the Earth’s oceans are rising nearly three times as rapidly as they were throughout most of the 20th century, one of the strongest indications yet that a much feared trend of not just sea level rise, but its acceleration, is now underway. “We have a much stronger acceleration in sea level rise than formerly thought,” said Sönke Dangendorf, a researcher with the University of Siegen in Germany who led the study along with scientists at institutions in Spain, France, Norway and the Netherlands.
Their paper, just out in the Proceedings of the National Academy of Sciences, isn’t the first to find that the rate of rising seas is itself increasing — but it finds a bigger rate of increase than in past studies. The new paper concludes that before 1990, oceans were rising at about 1.1 millimeters per year, or just 0.43 inches per decade. From 1993 through 2012, though, it finds that they rose at 3.1 millimeters per year, or 1.22 inches per decade.
The cause, said Dangendorf, is that sea level rise throughout much of the 20th century was driven by the melting of land-based glaciers and the expansion of seawater as it warms, but sea level rise in the 21st century has now, on top of that, added in major contributions from the ice sheets of Greenland and Antarctica.
“The sea level rise is now three times as fast as before 1990,” Dangendorf said….Kopp added that in the past five years, there is some indication that sea level rise could already be even higher than the 3.1 millimeter annual rate seen from 1993 through 2012. He cautioned, though, that “those higher rates over a short period of time probably include some level of natural variability as well as continued, human-caused acceleration.”…“Sea levels will continue to rise over the coming century, no matter whether we will adapt or not, but I think we can limit at least a part of the sea level rise. It will further accelerate, but how much is related to how we act as humans,” Dangendorf said
Maryland waters could be home to some of the nation’s first — and by far its largest — offshore wind farms after the state Public Service Commission on Thursday approved ratepayer subsidies to support a pair of projects off the coast of Ocean City….The decision could dot the Ocean City horizon with wind turbines as soon as 2020 — and add $1 to monthly residential electricity bills once the windmills start spinning. …
…“If built, these wind farms will be truly pioneering facilities, leading Maryland and the nation toward a 21st century economy that combats climate change and creates jobs in droves at the same time,” said Mike Tidwell, director of the Chesapeake Climate Action Network….
…The developers are required to build the turbines as far from shore as possible — up to 17 miles for the U.S. Wind farm and 24 miles for the Skipjack turbines. U.S. Wind officials have said that on a clear day, their turbines would appear to a person on the beach as about the size of a thumbnail at arms length…
Researchers are still studying the potential impacts such projects could have on wildlife, tracking migration patterns of birds such as red-throated loons to see how much they intersect with potential wind farm sites. Jennifer Mihills, of the Mid-Atlantic office of the National Wildlife Federation, said she thinks the projects “can be sited, constructed and operated in a manner that is protective of our coastal and marine wildlife.”…
The amount of dissolved oxygen contained in the water — an important measure of ocean health — has been declining for more than 20 years, reveals a new analysis of decades of data on oceans across the globe.
…Falling oxygen levels in water have the potential to impact the habitat of marine organisms worldwide and in recent years led to more frequent “hypoxic events” that killed or displaced populations of fish, crabs and many other organisms.
Researchers have for years anticipated that rising water temperatures would affect the amount of oxygen in the oceans, since warmer water is capable of holding less dissolved gas than colder water. But the data showed that ocean oxygen was falling more rapidly than the corresponding rise in water temperature.
“The trend of oxygen falling is about two to three times faster than what we predicted from the decrease of solubility associated with the ocean warming,” Ito said. “This is most likely due to the changes in ocean circulation and mixing associated with the heating of the near-surface waters and melting of polar ice.”….
….They found that air pollution drifting from East Asia out over the world’s largest ocean contributed to oxygen levels falling in tropical waters thousands of miles away. Once ocean currents carried the iron and nitrogen pollution to the tropics, photosynthesizing phytoplankton went into overdrive consuming the excess nutrients. But rather than increasing oxygen, the net result of the chain reaction was the depletion oxygen in subsurface water. That, too, is likely a contributing factor in waters across the globe, Ito said.
Takamitsu Ito, Shoshiro Minobe, Matthew C. Long, Curtis Deutsch. Upper Ocean O2 trends: 1958-2015. Geophysical Research Letters, 2017; DOI: 10.1002/2017GL073613
Climate change is predicted to cause a series of maladies for world oceans including heating up, acidification, and the loss of oxygen. A newly published study demonstrates that one ocean consequence of climate change that has already occurred is the spread and intensification of toxic algae.
Their study demonstrates that since 1982, broad stretches of these ocean basins have warmed and become significantly more hospitable to these algae and that new ‘blooms’ of these algae have become common in these same regions.Alexandrium and Dinophysis are serious health concerns as they make neurotoxins and gastrointestinal toxins that can cause paralytic and diarrhetic shellfish poisoning in humans.
…”The distribution, frequency and intensity of these events have increased across the globe and this study links this expansion to ocean warming in some regions of the North Atlantic and North Pacific Oceans,” Gobler said.
“A fundamental question has been whether we can directly link expansion of harmful algal blooms to a warming ocean; this paper provides critical, quantitative evidence for just that trend, confirming an expected, but difficult to test, direct link between toxic blooms to climate,” said Dr. Raphael Kudela, Professor of Ocean Sciences, University of California Santa Cruz, a national toxic algae expert who was not part of the study.
…”This study demonstrates that the global warming that has already occurred is now impacting human health and our oceans,” said Gobler. “An important implication of the study is that carbon emission and climate change-related policy decisions made today are likely to have important consequences for the fate of our future oceans, including the spread and intensification of toxic algal blooms.”
Christopher J. Gobler, Owen M. Doherty, Theresa K. Hattenrath-Lehmann, Andrew W. Griffith, Yoonja Kang, and R. Wayne Litaker. Ocean warming since 1982 has expanded the niche of toxic algal blooms in the North Atlantic and North Pacific oceans. PNAS, April 2017 DOI: 10.1073/pnas.1619575114