Oceans' acidic shift fastest in 300 million years

[jimmy olsen]

We're doomed! 

http://www.msnbc.msn.com/id/46594944/ns/us_news-environment/#.T1P5lYGb4wB

By Deborah Zabarenko
updated 3/1/2012 4:30:44 PM ET

WASHINGTON — The world's oceans are turning acidic at what could be the fastest pace of any time in the past 300 million years, even more rapidly than during a monster emission of planet-warming carbon 56 million years ago, scientists said on Thursday.

Looking back at that bygone warm period in Earth's history could offer help in forecasting the impact of human-spurred climate change, researchers said of a review of hundreds of studies of ancient climate records published in the journal Science.

Quickly acidifying seawater eats away at coral reefs, which provide habitat for other animals and plants, and makes it harder for mussels and oysters to form protective shells. It can also interfere with small organisms that feed commercial fish like salmon.

The phenomenon has been a top concern of Jane Lubchenco, the head of the U.S. National Oceanic and Atmospheric Administration, who has conducted demonstrations about acidification during hearings in the U.S. Congress.

Oceans get more acidic when more carbon gets into the atmosphere. In pre-industrial times, that occurred periodically in natural pulses of carbon that also pushed up global temperatures, the scientists wrote.

Human activities, including the burning of fossil fuels, have increased the level of atmospheric carbon to 392 parts per million from about 280 parts per million at the start of the industrial revolution. Carbon dioxide is one of several heat-trapping gases that contribute to global warming.

To figure out what ocean acidification might have done in the prehistoric past, 21 researchers from the United States, the United Kingdom, the Netherlands, Germany and Spain reviewed studies of the geological record going back 300 million years, looking for signs of climate disruption.
Advertise | AdChoices

Those indications of climate change included mass extinction events, where substantial percentages of living things on Earth died off, such as the giant asteroid strike thought to have killed the dinosaurs some 65 million years ago.

The events that seemed similar to what is happening now included mass extinctions about 252 million and 201 million years ago, as well as the warming period 56 million years in the past.

The researchers reckoned the 5,000-year hot spell 56 million years ago, likely due to factors like massive volcanism, was the closest parallel to current conditions at any time in the 300 million years.

To detect that, they looked at a layer of brown mud buried under the Southern Ocean off Antarctica. Sandwiched between layers of white plankton fossils, the brown mud indicated an ocean so acidic that the plankton fossils from that particular 5,000-year period dissolved into muck.

During that span, the amount of carbon in the atmosphere doubled and average temperatures rose by 10.8 degrees F, the researchers said. The oceans became more acidic by about 0.4 unit on the 14-point pH scale over that 5,000-year period, the researchers said.

That is a fast warm-up and a quick acidification, but it is small compared with what has happened on Earth since the start of the industrial revolution some 150 years ago, study author Baerbel Hoenisch of Columbia University's Lamont-Doherty Earth Observatory said by telephone.

During the warming period 56 million years ago, known as the Paleocene-Eocene Thermal Maximum, or PETM, and occurring about 9 million years after the extinction of the dinosaurs, acidification for each century was about .008 unit on the pH scale, Hoenisch said.

Back then, many corals went extinct, as did many types of single-celled organisms that lived on the sea floor, which suggests other plants and animals higher on the food chain died out too, researchers said.

By contrast, in the 20th century, oceans acidified by .1 unit of pH, and are projected to get more acidic at the rate of .2 or .3 pH by the year 2100, according to the study.

The U.N. Intergovernmental Panel on Climate Change projects world temperatures could rise by 3.2 to 7 degrees F this century.

"Given that the rate of change was an order of magnitude smaller (in the PETM) compared to what we're doing today, and still there were these big ecosystem changes, that gives us concern for what is going to happen in the future," Hoenisch said.

Those skeptical of human-caused climate change often point to past warming periods caused by natural events as evidence that the current warming trend is not a result of human activities. Hoenisch noted that natural causes such as massive volcanism were probably responsible for the PETM.

She said, however, that the rate of warming and acidification was much more gradual then, over the course of five millennia compared with one century.

Richard Feely, an oceanographer at the U.S. National Oceanic and Atmospheric Administration who was not involved in the study, said looking at that distant past was a good way to foresee the future.

"These studies give you a sense of the timing involved in past ocean acidification events - they did not happen quickly," Feely said in a statement. "The decisions we make over the next few decades could have significant implications on a geologic timescale."

Copyright 2012 Thomson Reuters. Click for restrictions.

[Neil]

Good.  Tim's panic is music to my much more clever, experienced and scientifically-aware ears.

[Razgovory]

Maybe we'll finally know what caused the Permian-Triassic extinction.

[Darth Wagtaros]

Maybe we'll finally know what caused the Permian-Triassic extinction.

Jaron.

[jimmy olsen]

Good.  Tim's panic is music to my much more clever, experienced and scientifically-aware ears.

Ok, explain why I shouldn't panic.

[Razgovory]

Good.  Tim's panic is music to my much more clever, experienced and scientifically-aware ears.

Ok, explain why I shouldn't panic.

Well, you aren't made of coral for one thing.  Besides, all this climate stuff is a hoax, remember?  That is the line propagated by your party.

[Eddie Teach]

Good.  Tim's panic is music to my much more clever, experienced and scientifically-aware ears.

Ok, explain why I shouldn't panic.

I thought you were mock-panicking.

[jimmy olsen]

Good.  Tim's panic is music to my much more clever, experienced and scientifically-aware ears.

Ok, explain why I shouldn't panic.

I thought you were mock-panicking.

Well I was given the fact that it probably won't cause serious problems in my lifetime, even if the worse case scenario is correct. However I can definitely see it causing major problems in the 22nd-23rd centuries if the trend continues.

[Neil]

Good.  Tim's panic is music to my much more clever, experienced and scientifically-aware ears.

Ok, explain why I shouldn't panic.

Because the Earth has recovered from worse, and because the changes in climate are going to be fascinating.  It's like a lab experiment on a planetary scale.

Moreover, inferior peoples living close to the equator are going to die, with excellent results for the human race as a whole.

[KRonn]

This has been in the news for some years now. I remember talk of coral reefs eroding, etc. Actually kind of a very scary scenario I'd say, if there is a major change in the oceans. Human food supplies, aquatic food chain, could spell major effects on the oceans for generations.

Global weather change happens, has happened often in the planet's history, including many times in recorded human history. I don't think anyone in earlier times had any idea things were changed, or changing, so there was likely little worry about it. We know it happens, and might do well to find ways to be prepared for change, man made or natural, or a combination of the two.

[Razgovory]

Good.  Tim's panic is music to my much more clever, experienced and scientifically-aware ears.

Ok, explain why I shouldn't panic.

I thought you were mock-panicking.

Well I was given the fact that it probably won't cause serious problems in my lifetime, even if the worse case scenario is correct. However I can definitely see it causing major problems in the 22nd-23rd centuries if the trend continues.

How long are you planning to live?

[Darth Wagtaros]

Good.  Tim's panic is music to my much more clever, experienced and scientifically-aware ears.

Ok, explain why I shouldn't panic.

I thought you were mock-panicking.

Well I was given the fact that it probably won't cause serious problems in my lifetime, even if the worse case scenario is correct.

You have a citation for this?

[Tamas]

This has been in the news for some years now. I remember talk of coral reefs eroding, etc. Actually kind of a very scary scenario I'd say, if there is a major change in the oceans. Human food supplies, aquatic food chain, could spell major effects on the oceans for generations.

Global weather change happens, has happened often in the planet's history, including many times in recorded human history. I don't think anyone in earlier times had any idea things were changed, or changing, so there was likely little worry about it. We know it happens, and might do well to find ways to be prepared for change, man made or natural, or a combination of the two.

What would be nice is to remove the interest-driven shrilling at both ends of the global warming issue. Which is of course impossible. But if could be done, it could switch focus from the two extreme ends namely the ones of:
-global warming is not happening, praise Jesus!
-global warming is entirely man made, let's press for some CO2 limitations on the countries which are not totally opoosed to the idea, and we will stop the global change of climate

Instead of those it should be about:
-determining the reasonable slowdown of it which we can achieve, rationally
-and do that to preserve some industrial strength, helping preparations for the effects we cannot stop

[Josquius]

We do do that, don't we?
The shrill "Lets all go back to living in mud huts!" folk are a tiny and powerless minority. They pale in comparison to hte "global warming is a myth" nuts. The political concensus seems to be rather in the middle, recognising that it is happening but immediate concerns come first- though worrying a bit more about it would be for the best.

[Razgovory]

I'm not sure anything can really be done.