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Climate Change Reducing Ocean’s Carbon Dioxide Uptake

The ocean is taking up less carbon because of the warming caused by the carbon in the atmosphere,” says [Galen] McKinley, an assistant professor of atmospheric and oceanic sciences and a member of the Center for Climatic Research….

Photo: Ocean water

McKinley is the lead author of a new analysis in the journal Nature Geoscience (subs. req’d) that appears to resolve a major issue in climate science:  “How deep is the ocean’s capacity to buffer against climate change?”

We now know that as the ocean warms up, its ability to act as a carbon “sink” is diminishing.  We are seeing a dangerous, amplifying carbon-cycle feedback.

The study’s news release explains:

As one of the planet’s largest single carbon absorbers, the ocean takes up roughly one-third of all human carbon emissions, reducing atmospheric carbon dioxide and its associated global changes.

But “whether the ocean can continue mopping up human-produced carbon at the same rate” wasn’t entirely clear. “Previous studies on the topic have yielded conflicting results.”

Back in 2007, I reported that the long-feared saturation of one the world’s primary carbon sinks had apparently started.  Again in 2009, I discussed a study in Geophysical Research Letters (subs. req’d), “Sudden, considerable reduction in recent uptake of anthropogenic CO2 by the East/Japan Sea.”  Most, but not all, studies have suggested the ocean was either losing its ability to absorb CO2 or soon would (see list here).

This new study, however, is different and more comprehensive than previous ones:

The analysis differs from previous studies in its scope across both time and space. One of the biggest challenges in asking how climate is affecting the ocean is simply a lack of data, McKinley says, with available information clustered along shipping lanes and other areas where scientists can take advantage of existing boat traffic. With a dearth of other sampling sites, many studies have simply extrapolated trends from limited areas to broader swaths of the ocean.

This study combines “existing data from a range of years (1981-2009), methodologies, and locations spanning most of the North Atlantic into a single time series for each of three large regions called gyres, defined by distinct physical and biological characteristics.”

[The authors] found a high degree of natural variability that often masked longer-term patterns of change and could explain why previous conclusions have disagreed. They discovered that apparent trends in ocean carbon uptake are highly dependent on exactly when and where you look – on the 10- to 15-year time scale, even overlapping time intervals sometimes suggested opposite effects.

“Because the ocean is so variable, we need at least 25 years’ worth of data to really see the effect of carbon accumulation in the atmosphere,” she says. “This is a big issue in many branches of climate science – what is natural variability, and what is climate change?”

Working with nearly three decades of data, the researchers were able to cut through the variability and identify underlying trends in the surface CO2 throughout the North Atlantic.

During the past three decades, increases in atmospheric carbon dioxide have largely been matched by corresponding increases in dissolved carbon dioxide in the seawater. The gases equilibrate across the air-water interface, influenced by how much carbon is in the atmosphere and the ocean and how much carbon dioxide the water is able to hold as determined by its water chemistry.

But the researchers found that rising temperatures are slowing the carbon absorption across a large portion of the subtropical North Atlantic. Warmer water cannot hold as much carbon dioxide, so the ocean’s carbon capacity is decreasing as it warms.

McKinley says, “this is some of the first evidence for climate damping the ocean’s ability to take up carbon from the atmosphere.”

Unfortunately, this is not some of the first evidence that amplifying feedbacks dominate the carbon cycle:

Time is running out if we are to avoid levels of CO2 emissions and global warming that will rapidly take us to very high levels.

Below are earlier comments from the Facebook commenting system:

Prokaryotes

Feedbacks: Climate Change Reducing Ocean’s Carbon Dioxide Uptake and accelerates Hypoxia States.

http://tiny.cc/rq45n

July 12 at 7:46pm

Prokaryotes

Oceanographer: Nitrous Oxide Emitting Aquatic ‘Dead Zones’ Contributing To Climate Change “When suboxic waters (oxygen essentially absent) occur at depths of less than 300 feet, the combination of high respiration rates, and the peculiarities of a process called denitrification can cause N2O production rates to be 10,000 times higher than the average for the open ocean.”.
http://tiny.cc/rq45n

July 12 at 7:47pm

Prokaryotes

NO2 contains an unpaired electron and is an important component of smog. N2O is a greenhouse gas with tremendous global warming potential (GWP). When compared to carbon dioxide (CO2), N2O has 310 times the ability to trap heat in the atmosphere.[73] N2O is produced naturally in the soil during the microbial processes of nitrification and denitrification.
http://tiny.cc/rq45n

July 12 at 7:48pm

Prokaryotes

Ocean’s Harmful Low-Oxygen Zones Growing, Are Sensitive to Small Changes in Climate.

Oxygen-deprived areas in the world’s oceans usually found in deeper water are moving up to offshore areas and threatening coastal marine ecosystems by spurring the die-off of some species and overpopulation of others http://tiny.cc/rq45n.

July 12 at 7:49pm

Joan Savage

The major carbon absorbers (or sinks) all seem to be shifting. It would be excellent to see a meta-analysis of the whole batch, oceans, rain forests, temperate zone soils, Northern peats, phytoplankton, coral reefs.

July 12 at 9:58pm

Joan Savage

Manning and Keeling (2006) attributed a lot more than “a third” of the carbon absorption to oceans. They had estimates of 2.2 ± 0.6 Pg C yr−1 oceanic biotic sinks and 0.5 ± 0.7 Pg C yr−1 land biotic sinks.
http://onlinelibrary.wiley​.com/doi/10.1111/j.1600-08​89.2006.00175.x/abstract

July 12 at 10:22pm

Prokaryotes

In response to your input i added now a top-notice.

July 13 at 4:26am

 

Prokaryotes

Climate Change Drives Disease in Crucial Seaweed Species, Study Finds.

New research links the spread of disease in a type of seaweed that is critical for marine life to global warming.
http://www.reuters.com/art​icle/2011/07/12/idUS113986​751820110712

Google the headline if the link does not work…

July 13 at 4:10am

Prokaryotes

Rising ocean temperatures due to global warming have already been linked to coral reef deaths, destructive storms, shifting species distributions and harmful algal blooms. Now, a team of Australian researchers is adding a new and similarly daunting concern to that list: the spread of disease in “habitat-forming” seaweeds that are critical to marine health.

Scientists fear that the widespread loss of these seaweeds could have disastrous effects on creatures that rely on them for food and protection, such as sea hares, sea urchins and dozens of fish and invertebrate species.

“Seaweeds are the ‘trees’ of coastal temperate systems,” said Peter Steinberg, a marine biologist at the University of New South Wales and director of the Sydney Institute of Marine Science, who helped lead the research that was published in the journal Global Change Biology last month.

“They provide the food and habitat for many of the other organisms that live there. Without them, these systems are radically different,” he said.

Earlier studies documented rapid decline and disease in seaweeds during the past two decades, but this analysis was the first to examine whether climate change is driving illness in habitat-forming stands that provide life to vast numbers of marine organisms.

In a 2008 study, for instance, biologists failed to locate the seaweed Phyllospora comosa along a 45-mile stretch of New South Wales, Australia — despite evidence to suggest that the species covered the coastline 50 years ago and would still be there.

A previous paper published in 1995 in the journal Science found that off Australia’s coast the amount of coralline algal pathogen, a bacteria that infects coral and other habitat-forming plants, jumped from zero to 100 percent in just one year.

The new study by Steinberg and colleagues from the University of New South Wales in Sydney focused on Delisea pulchra, a type of red algae, or seaweed, found in an area around Australia, New Zealand and Antarctica considered to be a global warming hot spot. Ocean temperatures in that region have already increased at rates well above the global average — roughly 3.6 degrees Fahrenheit in the last century, due to the strengthening of the East Australian Current system that flows south toward the South Pole.

In normal conditions, D. pulchra produces molecules known as halogenated furanones that bind to bacterial receptor sites, acting as a kind of chemical defense against infection.

Through field and lab observations, however, researchers discovered that in warmer waters — in this case, in temperatures ranging from 57 to 79 degrees Fahrenheit — the seaweeds showed higher levels of disease, or “bleaching.”

They also found that seaweeds injected with antibiotics in the hot waters experienced less disease than those in similar temperatures that were left untreated, indicating that increased bacterial activity was driving disease.

July 13 at 4:19am

Prokaryotes

Notice the Rise of the Bacteria in every system!

July 13 at 4:19am

Prokaryotes

Trenberth on Tracking Earth’s energy.

Over the past 50 years, the oceans have absorbed about 90% of the total heat added to the climate system while the rest goes to melting sea and land ice, and warming the land surface and atmosphere. Because carbon dioxide concentrations have further increased since 2003 the amount of heat subsequently being accumulated should be even greater. #
http://www.skepticalscienc​e.com/Tracking_Earths_Ener​gy.html

Google the headline if the link does not work…

July 13 at 4:14am

mcdonald.ronald42

Uh, actually, after some sort of time lag, the oceans are likely to start emitting carbon. The time lag could be hundreds of years. But how lucky do we feel, at this point?

http://www.skepticalscienc​e.com/co2-lags-temperature​.htm

“In the case of warming, the lag between temperature and CO2 is explained as follows: as ocean temperatures rise, oceans release CO2 into the atmosphere.”

July 13 at 10:39am

Joan Savage

http://earthobservatory.na​sa.gov/Features/OceanCarbo​n/
has a handy graph showing the general physical relationship between CO2 concentration in water and water temperature, and compares pre-industrial atmospheric CO2 concentration, 2008 atmospheric CO2 concentration, and double that.

July 13 at 1:49pm

Joan Savage

SST in the area of the North Atlantic (the southernmost of the three gyres that Mckinley et al. noted is slowing down on carbon uptake) can be near-real-time observed at http://marine.rutgers.edu/​mrs/sat_data/?nothumbs=0&p​roduct=sst&region=bigbight.
The SST can be compared to the Earth Observatory NASA graph for CO2 concentration in water at a given temperature. Today the Florida coast SST is circa 30C, still allowing absorption from atmosphere today, but not surprisingly in an area where absorption is slowing down in the long term trend.

July 13 at 2:03pm

Joan Savage

Before someone else says it, not all of the FL coast is circa 30C today.

July 13 at 2:15pm

blogbob forsooth

All of these links are excellent sources of information. But you’re wasting your time. First, the Teabaggers don’t know how to read. Second, more than half of them will swear that last winter was the worst they’ve ever seen, so in their feeble minds it is impossible that average ambient temperature is increasing.

July 15 at 7:30am

Comments are closed.

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