Archivi tag: Reuters

World’s oceans turn acidic fastest in 300 mln years

CLIMATE-OCEANS/ACID
Oceans’ acidic shift may be fastest in 300 mln years
* Study finds prehistoric clues about climate change impact
* Acid waters could endanger oysters, mussels, salmon
* Few parallels seen in 300-million-year record

WASHINGTON, March 1 (Reuters) – 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.
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 (6
degrees C), 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.

EXTINCTIONS ON THE SEAFLOOR
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 (1.8 to 4
degrees C) 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.”

(Editing by Peter Cooney)
REUTERS


Google takes on Facebook with latest social tweak

The Virtual World War

Google takes on Facebook with latest social tweak
* New feature lets users endorse search results
* Feature does not currently affect search result ranking
* Highlights Google’s battle with Facebook
(Adds details on feature, link to FTC settlement, byline)
Google Inc will begin allowing users to personally endorse search results and Web pages, its latest attempt to stave off rival Facebook Inc while trying to jump onboard a social networking boom.
The so-called “+1” button will start to appear alongside Google search results for select users from Wednesday, letting people recommend specific search results to friends and contacts by clicking on that button.
Eventually, the feature may begin to influence the ranking of search results, though that is only under consideration.
Results are now ranked via a closely guarded algorithm.
The world’s leader in Internet search is battling to maintain its share of Web surfers’ time and attention, which is increasingly getting taken up by Facebook, Twitter and other social networks. But it has struggled to find its footing in the nascent market.
Its last attempt to create a social network — Buzz — has not fared well. A flood of complaints about how Buzz handled user privacy cast a pall over the product. On Wednesday, Google announced it had reached a settlement with regulators under which it agreed to independent privacy audits every two years.
With the new +1 buttons, Google aims to counter one of Facebook’s most popular features. The new feature comes nearly a year after Facebook began offering special “Like” buttons to websites, creating a personalized recommendation system that some analysts believe could challenge the traditional ranking algorithms that search engines use to find online information.
A LOSING BATTLE?
Maintaining its role as the main gateway to information on the Internet is key for Google, which generated roughly $29 billion in revenue last year — primarily from search ads.
While Google remains the Internet search and advertising leader, Facebook is taking a larger and larger portion of advertising dollars.
Google said that +1 recommendations will also appear in the paid ads that Google displays alongside its search results. In its internal tests, Google found that including the recommendations boosted the rates at which people click on the ads, executives told Reuters in an interview on Tuesday.
Eventually, Google plans to let third-party websites feature +1 buttons directly on their own pages, the company said.
Google’s Matt Cutts, a principal engineer for search, said the +1 buttons were part of the evolution of Google’s own social search efforts, rather than a direct response to Facebook’s Like buttons.
“We always keep an eye out on what other people are doing, but for me the compelling value is just that it’s right there
in the search results,” said Cutts.
Google introduced social search in 2009, and in February the company began displaying special snippets underneath any search results that have been shared by a person’s contacts on Twitter, the popular Internet microblogging service.
Currently Google is not using +1 recommendations as a factor in how it ranks search results — a user only sees that a friend recommended a search result if the result would have turned up in a search based on Google’s existing ranking criteria.
Google’s Cutts said the company is evaluating whether to use +1 recommendations as a ranking factor in the future.
To use the new recommendation system, users must create a Google Profile page. Any +1 clicks that a person makes will be publicly visible to their network of contacts, which is based on existing contacts in Google products such as the company’s Gmail email and its instant messaging service.
Google faced privacy criticisms last year when it launched Buzz, a social networking messaging product that automatically revealed people’s personal contact lists to the public.
Cutts said that Google hoped to address any potential privacy concerns with the +1 service by making it clear that any +1 tags are public.
“As long as people have that mental model, they know what to expect, they’re not surprised if they +1 something and it shows up in a different context,” he said.
The feature will initially be available to a small portion of Google users in the United States on Wednesday, and the company plans to allow other U.S. users to sign up to try the +1 feature later in the day.


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