Lady Darwin
‘Unprecedented Rapidity of CO2’ Causing Worst Ocean Acidification in 300 Million Years
“We are entering an unknown territory of marine ecosystem change;” ocean acidification called “evil twin” of climate change.
The Earth’s oceans are becoming more acidic at a faster rate than at any time in the past 300 million years due to increased levels of CO2 in the atmosphere, a new study shows.
The study, published in the journal Science, details the work of 21 scientists from the U.S. and Europe.
“The geological record suggests that the current acidification is potentially unparalleled in at least the last 300 million years of Earth history, and raises the possibility that we are entering an unknown territory of marine ecosystem change,” said co-author Andy Ridgwell of Bristol University.
The Albany Times Union explains:
Ocean acidification works like this: Burning of fossil fuels like oil, coal and natural gas releases the greenhouse gas carbon dioxide (CO2) into the atmosphere, There, the gas keeps more of the heat from the sun from radiating back into space, a process that an international scientific consensus says is gradually raising the planet’s temperature.
At the same time, about a quarter of the increasing CO2 is being absorbed by the oceans, where it is converted into carbonic acid. This is steadily making the ocean more acidic, which among other things can harm the ability of sea creatures to thrive, or make hard shells or skeletons. Rising acidification can also affect marine organisms by causing slower growth, fewer offspring, muscle wastage and dwarfism.
Some scientists have called this gradual process the “evil twin” of climate change.
The study “raises the possibility that we are entering an unknown territory of marine ecosystem change,” said Andy Ridgwell, a professor of planetary modeling at the University of Bristol who took part in the study.
Agence France-Presse reports on the study:
The acidification may be worse than during four major mass extinctions in history when natural pulses of carbon from asteroid impacts and volcanic eruptions caused global temperatures to soar, said the study in the journal Science. […]
They found only one time in history that came close to what scientists are seeing today in terms of ocean life die-off — a mysterious period known as the Paleocene-Eocene Thermal Maximum about 56 million years ago.
Though the reason for the carbon upsurge back then remains a source of debate, scientists believe that the doubling of harmful emissions drove up global temperatures by about six degrees Celsius and caused big losses of ocean life. […]
“We know that life during past ocean acidification events was not wiped out — new species evolved to replace those that died off,” said lead author Barbel Honisch, a paleoceanographer at Columbia University’s Lamont-Doherty Earth Observatory.
“But if industrial carbon emissions continue at the current pace, we may lose organisms we care about — coral reefs, oysters, salmon.”
Honish and colleagues said the current rate of ocean acidification is at least 10 times faster than it was 56 million years ago.
Ars Technica adds:
While the authors frequently point out the difficulty in teasing apart the effects of ocean acidification and climate change, they argue that this is really an academic exercise. It’s more useful to consider the witches’ brew with all the ingredients—acidification, temperature change, and changes in dissolved oxygen—since, historically, those have come together. That combination produces unequivocally bad news.
The authors conclude, “[T]he current rate of (mainly fossil fuel) CO2 release stands out as capable of driving a combination and magnitude of ocean geochemical changes potentially unparalleled in at least the last ~300 [million years] of Earth history, raising the possibility that we are entering an unknown territory of marine ecosystem change.”
Ocean acidification is something I’ve talked about quite a bit on this blog and it’s an extremely important issue. You can read my posts on the topic here, here, here, here, and here.
March 2012
73 posts
By Jason Koebler / U.S. News and World Report
If you happen to see a frog hopping around in your back yard, take a good look— it might not be around for much longer. Ecologists are increasingly warning that due to habitat destruction, widespread infectious disease and climate change, amphibians are facing “extinction in real time.”
As many as 40 percent of amphibious species, which include frogs, salamanders and newts, could be facing “imminent extinction,” according to David Wake, a researcher at the University of California Berkeley.
“It’s happening around the world … we’re seeing it on our watch,” he says. “People talk more about birds or mammals because they are charismatic, they’re in the public eye. I’m concerned about rhinos and tigers, too, but in the meantime, we’re losing the things that are in our backyard.”
Scientists first began noticing the decline in the late 1980s, but despite increased awareness, amphibious populations haven’t grown.
“If anything, the problem has gotten worse,” Wake says. “The attention we’ve given to it has led to some surprising discoveries,” such as Chytridiomycosis, an infectious disease caused by a fungus that lives around the world and has a near 100 percent mortality rate in amphibious animals. So far, biologists haven’t been able to stop the disease.
Researchers disagree, however, on why we might soon have to say farewell to frogs forever. A controversial paper published in November by Christian Hof, a researcher at the University of Copenhagen, asserted that climate change is one of the biggest reasons the amphibian population is in worldwide decline. In an analysis released Friday in Science Magazine, Wake admits amphibians might be susceptible to changing climates, but their survival over millions of years points towards adaptability.
“With their moist and seemingly delicate skins, amphibians might be highly susceptible to climate change, but they are long-term survivors, having gotten through the end-Cretaceous extinctions and Pleistocene climate changes,” he writes. Habitat destruction and Chytridiomycosis are more imminent problems, he says.
Bill Nye
Mama, Don’t Let Your Babies Grow Up to Deny Evolution
(via Big Think)
