NASA via Reuters, file

The Sheldon Glacier with Mount Barre in the background, is seen from Ryder Bay near Rothera Research Station, Adelaide Island, Antarctica, in this NASA handout photo.

OSLO, Norway - Global warming is expanding the extent of sea ice around Antarctica in winter in a paradoxical shift caused by cold plumes of summer melt water that re-freeze fast when temperatures drop, according to a study unveiled Sunday.

An increasing summer thaw of ice on the edges of Antarctica, twinned with less than expected snowfall on the frozen continent, is also adding slightly to sea level rise in a threat to low-lying areas around the world, it said.

Climate scientists have been struggling to explain why sea ice around Antarctica has been growing, reaching a record extent in the winter of 2010, when ice on the Arctic Ocean at the other end of the planet shrank to a record low in 2012.

Sinead Farrell / NASA

Ice floes are shown at the foot of an iceberg in Antarctica's Amundsen Sea in October 2010.

"Sea ice around Antarctica is increasing despite the warming global climate," said Richard Bintanja, lead author of the study at the Royal Netherlands Meteorological Institute.

"This is caused by melting of the ice sheets from below," he told Reuters of the findings in the journal Nature Geoscience.

Ice is made of fresh water and, when ice shelves on the fringes of Antarctica thaw in summer because of upwellings of warming sea water, the meltwater forms a cool layer that floats on the denser, warmer salty sea water below, the study said.

In winter, the melt water readily turns to ice because it freezes at zero degrees Celsius, above sea water at -2C (28.4F).

At a winter maximum in September, ice on the sea around Antarctica covers about 19 million sq kms (7.3 million sq miles), bigger than Antarctica's land area. It then melts away into the ocean as summer approaches.

Among other scientists, Paul Holland of the British Antarctic Survey stuck to his findings last year that a shift in winds linked to climate change was blowing a layer of melt water further out to sea and adding to winter ice.

"The possibility remains that the real increase is the sum of wind-driven and melt water-driven effects, of course. That would be my best guess, with the melt water effect being the smaller of the two," he said.

Bintanja's study also said the cool melt water layer may limit the amount of water sucked from the oceans that falls as snow on Antarctica. Cold air can hold less moisture than warm.

"Cool sea surface temperatures around Antarctica could offset projected snowfall increases in Antarctica, with implications for estimates of future sea-level rise," it said.

The U.N. panel of climate scientists has estimated that sea levels will rise by between 18 and 59 cm (7-24 inches) this century, more if thaws of Antarctica and Greenland accelerate.

The panel's main scenarios assume that Antarctica alone will make sea levels fall by between 2 and 14 cms this century because more snowfall will extract water from the sea.

But Sunday's study said that Antarctica was losing about 250 billion tonnes of ice a year - equivalent to 0.07 millimetre(0.003 inch) of sea level rise a year, Bintanja said. "Antarctic mass loss seems to be accelerating," it said.

Another study in Nature Geoscience said Antarctica's snowfall had been over-estimated by between 11 and 36.5 billion tonnes a year because of fierce winds blasting many regions.

Strong winds created conditions to "sublimate" snow, or make it pass from a frozen state to a gas without first becoming liquid, a U.S.-led team wrote. 

Alister Doyle / Reuters file

Climate change is turning Antarctica's ice into one of the biggest risks for coming centuries, scientists say.

West Antarctica is warming almost twice as fast as previously believed, adding to worries of a thaw that would add to sea level rise from San Francisco to Shanghai, a study showed on Sunday. 

Annual average temperatures at the Byrd research station in West Antarctica had risen 2.4 degrees Celsius (4.3 Farenheit) since the 1950s, one of the fastest gains on the planet and three times the global average in a changing climate, it said. 

The unexpectedly big increase adds to fears the ice sheet is vulnerable to thawing. West Antarctica holds enough ice to raise world sea levels by at least 3.3 meters (11 feet) if it ever all melted, a process that would take centuries. 

"The western part of the ice sheet is experiencing nearly twice as much warming as previously thought," Ohio State University said in a statement of the study led by its geography professor David Bromwich. 

The warming "raises further concerns about the future contribution of Antarctica to sea level rise," it said. Higher summer temperatures raised risks of a surface melt of ice and snow even though most of Antarctica is in a year-round deep freeze. 

Low-lying nations from Bangladesh to Tuvalu are especially vulnerable to sea level rise, as are coastal cities from London to Buenos Aires. Sea levels have risen by about 20 centimeters (8 inches) in the past century. 

The United Nations panel of climate experts projects that sea levels will rise by between 18 and 59 cms (7-24 inches) this century, and by more if a thaw of Greenland and Antarctica accelerates, due to global warming caused by human activities.

The rise in temperatures in the remote region was comparable to that on the Antarctic Peninsula to the north, which snakes up towards South America, according to the U.S.-based experts writing in the journal Nature Geoscience. 

Parts of the northern hemisphere have also warmed at similarly fast rates. 

Annual bird counts give scientists climate clues

Several ice shelves - thick ice floating on the ocean and linked to land - have collapsed around the Antarctic Peninsula in recent years. Once ice shelves break up, glaciers pent up behind them can slide faster into the sea, raising water levels.

"The stakes would be much higher if a similar event occurred to an ice shelf restraining one of the enormous West Antarctic ice sheet glaciers," said Andrew Monaghan, a co-author at the U.S. National Center for Atmospheric Research. 

The Pine Island glacier off West Antarctica, for instance, brings as much water to the ocean as the Rhine river in Europe. 

The scientists said there had been one instance of a widespread surface melt of West Antarctica, in 2005. "A continued rise in summer temperatures could lead to more frequent and extensive episodes of surface melting," they wrote. 

Watch World News videos on NBCNews.com

West Antarctica now contributes about 0.3 mm a year to sea level rise, less than Greenland's 0.7 mm, Ohio State University said. The bigger East Antarctic ice sheet is less vulnerable to a thaw. 

Helped by computer simulations, the scientists reconstructed a record of temperatures stretching back to 1958 at Byrd, where about a third of the measurements were missing, sometimes because of power failures in the long Antarctic winters. 

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Osama Faisal / AP

Activists criticizing what they called a slow pace to climate talks protest Saturday at the convention center in Qatar. Norway's environment minister, Bard Vegar, speaks to some of them.

DOHA, Qatar -- Almost 200 nations on Saturday extended until 2020 a weak international plan for fighting global warming, averting a new setback to two decades of U.N. efforts that have failed to halt rising greenhouse gas emissions. 

The eight-year extension of the Kyoto Protocol keeps it alive as the sole legally binding plan for combating global warming. But it was sapped by the withdrawal of Russia, Japan and Canada, so its signatories now account for only 15 percent of global greenhouse emissions.

A package of decisions, known as the Doha Climate Gateway, would also postpone until 2013 a dispute over demands from developing nations for more cash to help them cope with global warming.

All sides say the Doha decisions fell far short of recommendations by scientists for tougher action.

Though expectations were low for the two-week conference, many developing countries rejected the deal as insufficient to put the world on track to fight the rising temperatures that are raising sea levels. Some Pacific island nations see this as a threat to their existence.

"This is not where we wanted to be at the end of the meeting, I assure you," said Nauru Foreign Minister Kieren Keke, who leads an alliance of small island states. "It certainly isn't where we need to be in order to prevent islands from going under and other unimaginable impacts."

"It was not an easy ride. It was not a beautiful ride. It was not a fast ride, but we managed to cross the bridge and hopefully we can increase our speed," added European Climate Commissioner Connie Hedegaard.

She said the deal would pave the way to talks on a new, global U.N. pact meant be agreed in 2015 and enter into force in 2020, when Kyoto now expires. It will have emissions goals for all, including emerging nations led by China and India.

The 1997 Kyoto Protocol, which controls the greenhouse gas emissions of rich countries, expires this year. However, the second phase only covers about 15 percent of global emissions after Canada, Japan, New Zealand and Russia opted out.

Originally, Kyoto obliged about 35 industrialized nations to cut greenhouse gas emissions by an average of at least 5.2 percent below 1990 levels during the period from 2008 to 2012.

The U.S. never joined Kyoto, partly because it didn't include China and other fast-growing developing countries.

Poor countries came into the talks in Doha demanding a timetable on how rich countries would scale up climate change aid for them to $100 billion annually by 2020 — a general pledge that was made three years ago.

But rich nations -- including the United States, members of the European Union and Japan -- are still grappling with the effects of a financial crisis and were not interested in detailed talks on aid in Doha.

The agreement on financing made no reference to any mid-term financing targets, just a general pledge to "identify pathways for mobilizing the scaling up of climate finance."

The two-week U.N. meeting had been due to end on Friday but the talks went on into Saturday evening.

World carbon dioxide emissions are set to rise by 2.6 percent this year, and are more than 50 percent higher than in 1990. Recent growth has come mostly from emerging nations, led by China and India.

The Associated Press and Reuters contributed to this report.

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What had been a blurry picture about polar ice — especially how it impacts sea levels — just got a whole lot clearer as experts on Thursday published a peer-reviewed study they say puts to rest the debate over whether the poles added to, or subtracted from, sea level rise over the last two decades.

"This improved certainty allows us to say definitively that both Antarctica and Greenland have been losing ice," lead author Andrew Shepherd of the University of Leeds in Britain, told reporters. Not only that, but the pace has tripled from the 1990s, the data indicate.

Combining satellite data from dozens of earlier studies, the study "shows that the Antarctic and Greenland ice sheets have contributed just over 11 millimeters (0.4 inches) to global sea levels since 1992," he added. Two-thirds was from Greenland, a third from Antarctica.

NASA Earth Observatory

This 20-mile-long rift on Antarctica's Pine Island Glacier, seen from a satellite on Oct. 26, will eventually calve off, possibly in the next few months, creating an iceberg the size of New York City. While that won't raise sea levels since the glacial tongue sits on water, the loss could speed up the flow of ice from Antarctica's mainland into the sea.

That's 20 percent of all sea level rise over the last two decades, with the rest mostly from thermal expansion of waters due to warming sea temperatures, the authors noted. In recent years, however, the percentage "has gone up significantly" to nearly 40 percent, added co-author Michiel van den Broeke from Utrecht University in the Netherlands.

Published in the journal Science, the study was based on input from 47 experts at the 26 institutes that produced earlier studies with wild variations. Some of those studies estimated melt was raising sea levels by up to 2 millimeters a year, Shepherd noted, while a few said that overall polar ice was growing, and thus countering sea level rise.

Much of the discrepancy was due to data showing that Antarctica's vast eastern ice sheet was adding, not losing ice.

Eastern Antarctica has indeed added ice, but continent-wide the last decade shows a "50 percent increase in ice loss rate," said study co-author Erik Ivins, a satellite data expert with NASA's Jet Propulsion Lab. 

Most of that loss is in western Antarctica — at places like Pine Island Glacier, where an iceberg the size of New York City is set to calve off. The iceberg itself won't raise sea levels since that ice is already atop water, but thinning glaciers mean that ice on the mainland can make its way downhill to the sea faster.

ESA/NASA/Planetary Visions

Based on the new study in Science, this chart shows changes in global sea level due to ice sheet melting since 1992. The background image shows thickening (blue) and thinning (red) of Antarctica's ice sheets over the same period.

Even more dramatic, Ivins said, is that Greenland "is losing mass at about five times the rate today as it was in the early 1990s."

Greenland's melt rate has gone from 55 billion tons a year in the 1990s to nearly 290 billion tons a year recently, according to the study. 

A top ice expert who was not a study co-author told NBC News that the new data mark "an important step forward" in better estimating future sea level rise.

"While we had a basic picture of what was going on, it was an incomplete and blurry one," said Mark Serreze, director of the National Snow and Ice Data Center at the University of Colorado-Boulder. "We needed to step back and take a fresh look, making the best use of all of the different data sources that we have.

"With this study," he added, "we now have a lot confidence in how the ice sheets are behaving."

The findings come as nations negotiate in Qatar over a new climate treaty to replace the 1997 Kyoto Protocol, which aimed to reduce carbon dioxide and other greenhouse gases tied to a warming Earth. 

And while a 0.4 inch rise in sea levels over 20 years doesn't sound like much, many experts fear further warming will accelerate the polar melt. The ice sheets would raise sea levels by more than 200 feet if they completely melted over centuries — not likely, but even a tenth of that would have catastrophic impacts on coastal areas.

The authors warned that while the new data should become the benchmark for future forecasts, any new studies could be compromised if aging satellites are not replaced. In the U.S., the Obama administration is overhauling its satellite program after an outside review team found it "dysfunctional."

Related: Sea levels rose 60 percent faster than forecast, study finds

"It’s really critical that these measurements are sustained and several satellites are beginning to fail," noted Ian Joughin, a University of Washington researcher.

"If we really want to have meaningful information that you know planners can use to build seawalls," he added, "there’s going to have to be a big push to improve our projections of sea level rise using models."

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Projections for sea level rise in coming decades could be too conservative, experts warned Wednesday, saying they found that the rise over the last two decades is much more than predicted by the U.N. scientific body tracking climate signals.

In a peer-reviewed study, the experts said satellite data show sea levels rose by 3.2 millimeters (0.1 inch) a year from 1993 to 2011 — 60 percent faster than the 2 mm annual rise projected by the U.N.'s Intergovernmental Panel on Climate Change for that period. 

"This suggests that IPCC sea-level projections for the future may also be biased low," the team wrote in the journal Environmental Research Letters. 

The experts also said the IPCC was just about spot on with its predictions for warming temperatures.

"Global warming has not slowed down or is lagging behind the projections," lead author Stefan Rahmstorf, a researcher at Germany's Potsdam Institute for Climate Impact Research, said in a statement. "The IPCC is far from being alarmist and in fact in some cases rather underestimates possible risks." 

The experts added that the faster sea level rise is unlikely to be caused by a temporary ice discharge from Greenland or Antarctica ice sheets because it correlates very well with the increase in global temperature.

The IPCC earlier estimated that seas rose by about 7 inches over the last century, and its most recent report, published in 2007, estimated a range of between 7 and 23 inches this century — enough to worsen coastal flooding and erosion during storm surges.

But the IPCC report did not factor in a possible acceleration of the melt of the Greenland and Antarctic ice sheets.

The IPCC "assumed that Antarctica will gain enough (ice) mass" to compensate for Greenland ice loss, the new study's authors noted, but more recent studies have shown that "the ice sheets in Greenland and Antarctica are increasingly losing mass."

Related: Ice melt found across 97 percent of Greenland

Rahmstorf told Reuters his best estimate for sea level rise was between 20 inches and three feet this century, possibly more if greenhouse gas emissions of carbon dioxide surged.

The IPCC chair, addressing delegates to international climate talks being held in Doha, Qatar, on Wednesday made note of the recent findings on ice loss and sea level rise.

The next IPCC report, Rajendra Pachauri promised, will have "a better appreciation of mass loss of the large ice sheets of Greenland and Antarctica."

When the next IPCC report comes out in March 2014, he added, expect "a more quantitative understanding of ongoing sea level rise" — and an entire chapter on the topic.

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DOHA, Qatar -- Despite cooling from La Nina early in the year, 2012 is on track to become one of the top 10 warmest years on record, with the U.S. experiencing extreme warmth and Arctic Sea ice shrinking to its lowest extent, the U.N. weather agency said Wednesday.

In a statement released at international climate talks in Qatar, the World Meteorological Organization said the "alarming rate" of the Arctic melt highlights the far-reaching changes caused by global warming.

"Climate change is taking place before our eyes and will continue to do so as a result of the concentrations of greenhouse gases in the atmosphere, which have risen constantly and again reached new records," WMO Secretary-General Michel Jarraud said.

Delegates from nearly 200 countries are meeting in Doha, Qatar, to discuss ways of slowing climate change, including by cutting emissions of greenhouse gases that scientists say are warming the planet, melting ice caps, raising sea levels, and changing rainfall patterns with impacts on floods and droughts.

Discord between rich and poor countries on who should do what has kept the two-decade-old U.N. talks from delivering on that goal, and global emissions are still going up.

The WMO said global temperatures rose after initial cooling caused by the La Nina weather oscillation, with major heat waves in the U.S. and Europe. Average temperatures in January-October were the highest in the continental U.S., and the ninth highest worldwide, since records began in 1850.

Cyclone activity was normal globally, but above average in the Atlantic, where 10 storms reached hurricane strength, including Sandy, which wreaked havoc across the Caribbean and the U.S. East Coast.

Sandy wasn't the strongest cyclone, though. That was Typhoon Sanba, which struck the Philippines, Japan, and the Korean Peninsula, "dumping torrential rain and triggering floods and landslides that affected thousands of people and caused millions in U.S. dollars in damage," the WMO said.

Related: Permafrost melt needs to be factored into talks, experts say

Droughts impacted the U.S., Russia, parts of China and northern Brazil. Nigeria saw exceptional floods, while southern China saw its heaviest rainfall in three decades.

But of all the weather events in 2012, the most ominous to climate scientists was the loss of ice cover on the North Pole. In September, scientists at the National Snow and Ice Data Center in Colorado said Arctic Sea ice measured 1.32 million square miles — which is 18 percent less than the previous record low, set in 2007. Records go back to 1979 based on satellite tracking.

The scientists said their computer models predict the Arctic could become essentially free of ice in the summer by 2050, but added that current trends show ice melting faster than the computers are predicting.

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All the back and forth over climate change negotiations hasn't dealt with a looming problem: melting permafrost could account for more than a third of all warming emissions by 2100, experts warned Tuesday, and yet nations haven't factored it into reduction targets.

"Permafrost is one of the keys to the planet’s future because it contains large stores of frozen organic matter that, if thawed and released into the atmosphere, would amplify current global warming," U.N. Environment Program Director Achim Steiner said in announcing the report by top permafrost scientists.

"Continuing to ignore the challenges of warming permafrost" is not an option, he added.

The report was released as nations gather in Doha, Qatar, this week for the latest round of climate treaty talks that aim to limit warming by the year 2100 to 2 degrees Celsius (3.6 degrees Fahrenheit) above pre-industrial temperatures.

"Permafrost has begun to thaw," lead author Kevin Schaefer, a researcher at the National Snow and Ice Data Center at the University of Colorado-Boulder, told a news conference in Doha.

"Permafrost emissions could ultimately account for up to 39 percent of total (greenhouse gas) emissions," he warned. "This must be factored into treaty negotiations ... or we risk overshooting the 2 degrees Celsius maximum warming target."

Permafrost, defined as ground that stays frozen for at least two years in a row, stores vast quantities of carbon dioxide and methane, both gases that contribute to the greenhouse effect warming the Earth.

United Nations Environment Program

This map shows one scenario of permafrost melt using climate models. The scenario shows a nearly 59 percent loss in near-surface permafrost by 2100.

Widespread thaw would create a vicious circle, since the release of more CO2 and methane would trap more heat in the air and in turn accelerate the melting. That, in turn, could bring an irreversible, runaway effect. 

The experts predicted an irreversible loss of between 30 and 85 percent of permafrost near the surface. That was based on a forecast of Arctic temperatures rising by 6 degrees C (10.8 F) through 2100.

The permafrost report follows reports by the World Bank and the U.N. Environment Program warning that rising world greenhouse gas emissions, even without permafrost contributions, were on track to push up temperatures well beyond 2 degrees C by 2100. 

At Doha, nations are negotiating around extending the Kyoto Protocol — a legally-binding emissions cap that expires this year. 

Many rich countries such as Japan, Russia and Canada have refused to endorse an extension and want a completely new treaty. The United States was the lone industrialized country not to join the original pact in 1997 because it did not include other big emitters like China. 

Japan insists it would be better to focus on a new treaty by 2015.

"Only developed countries are legally bound by the Kyoto Protocol and their emissions are only 26 percent," Masahiko Horie, speaking for the Japanese delegation, said in Doha. "If we continue the same, only one quarter of the world is legally bound and three quarters of countries are not bound at all."

Related story: Rich-poor split persists at climate talks

But developing countries like Brazil are warning that it will be difficult for poor nations to do their part if they continue watching industrialized nations shy away from legally-binding pacts like Kyoto. 

Reuters and The Associated Press contributed to this report.

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Caitlin Seaview Survey

This was among the healthy coral found in deep waters below Australia's Great Barrier Reef during the October 2012 work by the Caitlin Seaview Survey.

A robot diving deeper than any human diver has found that coral deep below Australia’s Great Barrier Reef is very healthy even though the shallower coral is suffering from storms, warming seas and pollution. The robot’s handlers hope the deeper coral will provide the "recruits" needed to naturally repair the shallower reefs.

"Up until now our knowledge was limited to the shallow reefs accessible by scuba diving," Ove Hoegh-Guldberg, chief scientist for the Catlin Seaview Survey, said in a statement announcing the findings. "In reality, that provided us with an incomplete picture."

The remote-operated vehicle, he added, allows scientists to study coral at depths between 90 and 300 feet, "revealing a wholly different picture which now includes the deep reef environment."

John Bruno, a University of North Carolina coral expert not associated with the survey, welcomed the work. "This is a popular idea," he said of deeper coral providing a refuge, "just not well tested."

Caitlin Seaview Survey

The robot used by the Caitlin Seaview Survey takes a sample from a deepwater area of Australia's Great Barrier Reef during its October 2012 work.

Carden Wallace, a coral expert at the Museum of Tropical Queensland, added that it's not only the abundance but the diversity that surprised her. "Using the ROVs to film and collect samples at this scale is simply unprecedented in Australian waters," Wallace said.

That diversity includes corals that "are much flatter, more plate-like than the branching and domed shapes seen nearer the surface," said Pim Bongaerts of the University of Queensland’s Global Change Institute. "This is the corals responding to the reduced light conditions and spreading out to maximize their exposure to light.

"So far below the surface, the light is blue because all other parts of the spectrum have been filtered out," Bongaerts added. "It is a monochrome world until you turn on strong lights to reveal amazing, beautiful, fantastic colors."

The layer of coral just below the shallow reefs could be the key to repairing the reef system.

It "could provide coral recruits for the upper levels of the reef, providing a potential for them to help in the recovery," Bongaerts said. "At the moment we know little about the extent of larval movements between the shallow and deep reef, but we are seeing species that exist in both zones."

Related: 'Major decline' in Great Barrier Reef coral
Related: 360-degree views of Great Barrier Reef

Bruno was optimistic that nature would play a role in recovery. "The deep water habitats can/will be a sort of refuge," he told NBC News, calling it "a natural source to repopulate shallow habitats that have been more affected by warming, bleaching, disease, storms, etc."  

Caitlin Seaview Survey

A starfish sits on storm-damaged coral in shallow waters of Australia's Great Barrier Reef.

The findings come a month after the Australian Institute of Marine Science reported that the Great Barrier Reef has lost half its shallow-reef coral cover in the last 27 years. 

The Catlin team, for its part, is planning six more surveys along the 1,600-mile-long reef system. It plans to later study reef systems around the world, using ROVs as well as cameras with 360-degree views. 

Slideshow: Take a virtual dive

See dozens of wonders from coral reefs and other exotic seascapes, courtesy of the Catlin Seaview Survey.

Launch slideshow

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A 3,800-square-mile algae bloom in the Pacific Ocean off Canada's British Columbia has been traced to a California businessman who promised a local tribe he could help their salmon runs by fertilizing the ocean with iron.

The Guardian of London reported that Russ George acknowledged that in July his company, the Haida Salmon Restoration Corp., had dropped around 100 tons of ore with traces of iron, calling it the "most substantial ocean restoration project in history."

"We've gathered data targeting all the possible fears that have been raised" about ocean fertilization, George reportedly added. "And the news is good news, all around, for the planet."

Planktos, a separate company started by George, has wanted to experiment with ocean fertilization as a way to soak up carbon dioxide from the atmosphere. But Planktos has been stymied in bids to get government approval for the testing, which, if successful, could position the company to cash in on carbon trading credits aimed at reducing global warming.

Canada's environment ministry said it was investigating the experiment but would not elaborate.

Fertilization might be a way to soak up carbon dioxide, but it's also hotly debated among scientists.

"Some possible effects, such as deep-water oxygen depletion and alteration of distant food webs, should rule out ocean manipulation," John Cullen, an oceanographer at Dalhousie University, told The Guardian. "History is full of examples of ecological manipulations that backfired."

"It scares me," added Maite Maldonado, a  University of British Columbia researcher who specializes in the impact of trace minerals on ocean life.

"If you have a massive bloom or growth of this microscopic algae, you might not have enough oxygen in the water column at certain depths," Maldonado told the Canadian Broadcasting Corp.

The project is 100 times larger than any previous experiment in iron fertilization, she added.

Moreover, the project might have violated two international resolutions, Kristina Gjerde, an adviser to the International Union for Conservation of Nature, told the Guardian. 

"The placement of iron particles into the ocean, whether for carbon sequestration or fish replenishment, should not take place, unless it is assessed and found to be legitimate scientific research without commercial motivation," she said. "This does not appear to even have had the guise of legitimate scientific research."

The Haida nation reportedly put up more than $1 million for the test under the premise that an algae bloom would provide more food for salmon. The test itself was done some 200 miles west of the Haida Gwaii islands.

"The village people voted to support what they were told was a 'salmon enhancement project'," said the tribe's president, who goes by a single name Guujaaw. 

Guujaaw said the tribe "would not have agreed if they had been told of any potential negative effects or that it was in breach of an international convention."

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Courtesy NOAA Visualization Lab

NOAA scientists say the globally-averaged temperature last month, tied with the September record high set in 2005.

If you thought September felt a bit warmer than usual, you weren't alone.

Scientists with the National Oceanic and Atmospheric Administration (NOAA) said Monday that last month tied a 2005 record for the warmest September on record worldwide. These numbers have been tracked since 1880. September's combined average temperature over land and ocean around the world was 60.21 degrees Fahrenheit -- 1.21 degrees over the 20th century average.

The heat was most notable in parts of Russia, Japan, Australia, Argentina, Paraguay, Canada and Greenland. In the United States, September was only the 23rd hottest, The Associated Press reported.

The scientists also noted that September "also marked the 36th consecutive September and 331st consecutive month with a global temperature above the 20th century average."

Records such as this are seemingly being set at a greater rate than they used to be, according to Professor Jonathan E. Martin, chair of atmospheric and oceanic sciences at the University of Wisconsin-Madison. Martin says greenhouse gases are changing the composition of the atmosphere.

"One of the consequences of that is an easier time hurdling past high temperature records," Martin told NBC News, acknowledging that global warming could be at play.

With a September average of 1.39 million square miles, Arctic sea ice also reached its all-time lowest daily extent on record on Sept. 16. Martin speculated that there is a "very strong possibility" that this increased water exposure to the air could be affecting temperatures.

Related: Arctic sea ice reaches new low

The situation was different in the Antarctic, where sea ice actually reached its all-time highest daily extent record on Sept. 26.

Deke Arndt, chief of the climate monitoring branch at NOAA's National Climatic Data Center, said 2012 so far currently clocks in as eighth warmest year on record. Unless there are exceptionally high temperatures the rest of the year, 2005 and 2010 will likely continue holding the title for hottest years on record, he added.

The Associated Press contributed to this story.

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