Sun sets on climate change get-out clause

Potsdam Institute of Climate Research's Georg Feulner

Potsdam Institute of Climate Research’s Georg Feulner

Reduced heating from the Sun will not rescue Earth from global warming, according to Potsdam Institute for Climate Research’s Georg Feulner. “Many people believing in a strong Sun-climate connection suggested that this could save us,” he says. “This claim is not supported.”

Feulner and his colleague Stefan Rahmstorf have produced computer models simulating what would happen if the Sun entered an extended quiet period known as a “grand minimum”. The energy falling on the Earth from the sun normally varies between highs and lows over eleven year cycles. However, the cycle can get stuck at a low for decades, and with the current cycle’s low period already being unusually long, there has been speculation that we’re entering another grand minimum. “Four such minima have occurred during the last millennium, so a new grand minimum in the 21st century is entirely possible,” Feulner explains.

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Saturday round-up: Greenland’s ice loss spreads

Greenland is not only still losing ice to the sea but the rate has accelerated in the last decade, an international group of scientists has highlighted this week. As a consequence, while the increased loss had previously mainly been happening in Greenland’s south, ice is also now noticeably disappearing more rapidly from its north-west coast.

[Updated 20 Feb 2014] I have updated the animated movie of the spread of ice loss into northwest Greenland observed by satellite so that it now reaches from 2003 through to 2011 as the link to the old movie died. The colour scale shows ice thickness in centimetres.

“These changes on the Greenland ice sheet are happening fast, and we are definitely losing more ice mass than we had anticipated,” said team-member Isabella Velicogna of the University of California, Irvine. The team, led by Shfaqat Abbas Khan of the Danish National Space institute, used satellite and GPS data to measure the ice sheet that covers around 80% of Greenland’s surface. In the study, published in Geophysical Research Letters, they looked at the vertical movement of the land underneath the ice sheet. Ice sheets’ weight pushes the Earth’s surface beneath them down towards its core, but when the ice melts the surface can rebound back.

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For the love of science, not money

More walrus cubs being separated from their mothers are one effect mentioned by Louis Cotispodi as showing the effect that climate change is having in the Arctic (Photo by Phil Alatalo, Woods Hole Oceanographic Institution)

Louis Codispoti mentions walrus cubs being separated from their mothers as one effect that climate change is having in the Arctic (Photo by Phil Alatalo, Woods Hole Oceanographic Institution)

“I have had three colleagues killed while conducting research, so I take umbrage when hard-working, relatively under-paid, scientists are accused by the robber-barons and political hacks of hyping climate change for money.” So says Louis Codispoti, a scientist researching chemical processes happening in the ocean at the University of Maryland’s Horn Point Laboratory. At nearly 70, Codispoti is retiring to ease budget pressures at his university, but retains the title of professor and is beginning to pay for his own research.

Yet even without extensive funds, on March 12 Codispoti’s insights into how gas emissions from the ocean can add to global warming were published in the prestigious journal Science. Codispoti’s understanding of how the sea’s emissions of one particular gas – nitrous oxide, an especially dangerous greenhouse gas – might increase in relation to human activity has developed over 25 years. In that time, he’s seen researchers build the case for people causing climate change, and believes that the conclusions are backed up by way the world has changed in recent decades. Read the rest of this entry »

Saturday round-up: Warming tilts evolutionary playing field

 

Polar bears are among the group of High Arctic vertebrates whose average population has declined since 1970. Credit: USFWS

Polar bears are among the group of High Arctic vertebrates whose average population has declined since 1970. Credit: USFWS

The types of animals living in the Arctic, and trees across the rest of the whole world, are expected to change noticeably as the planet warms up. The Arctic Species Trend Index (ASTI) published on Wednesday notes that species adapted to disappearing High Arctic ecosystems could lose out to more southerly-dwelling creatures. Higher temperatures could also see trees able to take advantage of longer growing periods benefit compared to varieties with more rigid calendars, says a Science paper Read the rest of this entry »

Lots of shoes make for big carbon feet

China is by far the largest "exporter" of carbon dioxide emissions, as seen in this map of the net flow of emissions embodied in trade among the major exporting and importing countries. Arrows indicate direction and magnitude of flow; numbers are megatons (millions of tons). Credit: Steven Davis/Carnegie Institution for Science

China is by far the largest “exporter” of carbon dioxide emissions, as seen in this map of the net flow of emissions embodied in trade among the major exporting and importing countries. Arrows indicate direction and magnitude of flow; numbers are megatons (millions of tons). Credit: Steven Davis/Carnegie Institution for Science

Goods bought in the richest parts of the world effectively export CO2 emissions to poorer countries, a factor overlooked by governments’ climate change strategies. That’s the message coming from research in the news this month performed by two separate groups of researchers, one in the US and one in Norway. The Norway-based team of Edgar Hertwich and colleague Glen Peters in particular note that the carbon footprint continues to grow steadily in parallel with how much consumers spend. “There is no flattening out, no indication that the carbon footprint stabilizes at some point,” they write. Consequently, as nations continue to strive to raise their wealth, we might expect their carbon footprint to grow along with it. “This is, I’m afraid, bad news,” Peters and Hertwich say. “We cannot expect that emissions are reduced as a part of normal development.”

Hertwich and Peters last week won an award for the “Best Policy Paper” for 2009 from the journal Environmental Science and Technology that published their work. They looked at all countries’ carbon footprint in 2001, going further than just looking at CO2 produced within their borders to also assess the impact of international trade for the first time. Their results have been made into a website, called “Carbon Footprint of Nations”, which shows how emissions vary with consumption. Greenhouse gas emissions rise about 70% with each doubling of consumer spending, with more emissions coming from transport and consumer goods and less from food.

 The "Carbon Footprint of Nations" website created by Edgar Hertwich and Glen Peters shows international emissions in 2001.

The “Carbon Footprint of Nations” website created by Edgar Hertwich and Glen Peters shows international emissions in 2001.

On March 8 Ken Caldeira and Steven Davis at the Carnegie Institution in Stanford, California, also published a similar analysis of carbon footprints in 2004 in the Proceedings of the National Academy of Sciences. The study finds that, in 2004, 23% of global CO2 emissions, or 6.2 billion tons, were used to produce goods traded internationally. Per person, about 2.5 tons of CO2 are consumed in the U.S. but produced somewhere else. For Europeans, the figure can exceed four tons per person. Most of these emissions are outsourced to developing countries, especially China, where 22.5% of  the CO2 produced was for goods to be exported. “There is little evidence that carbon-intensive industries are being sited in developing countries in direct response to climate policy,” Caldeira and Davis write. “However, industrial expansion occurring in those countries may unintentionally undermine ongoing efforts to regulate emissions.”

“Where CO2 emissions occur doesn’t matter to the climate system,” Davis says. “Effective policy must have global scope. To the extent that constraints on developing countries’ emissions are the major impediment to effective international climate policy, allocating responsibility for some portion of these emissions to final consumers elsewhere may represent an opportunity for compromise.”

Hertwich and Peters suggest that improving production efficiency and using more renewable energy when manufacturing goods would also be useful. Nevertheless, they still seem uncertain that this will achieve enough. “If we really want to reduce climate change, it seems like the consumption of goods needs to be limited,” they write. This would not mean a complete halt, however, as the scientists note that consumption by rich households in both developing and industrialised nations is needed.

Saturday round-up: Dead zones reach skywards

University of Maryland's Louis Codispoti, who predicts increased nitrous oxide emissions from the sea could worsen climate change

University of Maryland's Louis Codispoti, who predicts increased nitrous oxide emissions from the sea could worsen climate change

The sea’s production of a greenhouse gas, caused in part due to human effluent, could increase as the world warms up. The nitrous oxide emitted due to changes in ocean make-up could worsen climate change, according to Louis Codispoti of the University of Maryland.

In the atmosphere, nitrous oxide strongly retains heat that would otherwise be lost into space. How much is released from the sea depends upon how much oxygen microbes living there have access to. If a given body of water were to fall from its maximum oxygen concentration to 1% of that, its nitrous oxide output would be 20 times greater.

Currently, human activity is thought to be reducing the oxygen content of many areas of the ocean, creating “dead zones”, also known as hypoxic waters. Sewage and fertiliser run-off promotes excessive plant growth in these regions. When these plants die, they are fed upon by micro-organisms that consume oxygen dissolved in the ocean, making it hard for fish and other creatures to live there. Read the rest of this entry »

Ice retreat offers chilling evidence

The Brunt Ice Shelf in Antarctica. While this ice shelf is not part of the area most recently studied by Ferrigno, ice shelves like this are retreating across the Antarctic Peninsula. Credit: Charles Swithinbank, British Antarctic Survey.

The Brunt Ice Shelf in Antarctica. While this ice shelf is not part of the area most recently studied by Ferrigno, ice shelves like this are retreating across the Antarctic Peninsula. Credit: Charles Swithinbank, British Antarctic Survey.

If you want to see the effects of global warming, just look at how the maps of Antarctica are changing. That’s the advice of Jane Ferrigno, a US Geological Survey (USGS) researcher, who led a recently-published study of ice cover in an area known as Palmer Land.

“The most important pieces of evidence are the visible data, the satellite imagery, the aerial photographs, and the maps that we used to compile our map and report,” Ferrigno told Simple Climate. “The evidence is there for anyone to look at.”

The study of Palmer Land, is the latest in a series mapping West Antarctica. Previous USGS surveys of the Antarctic Peninsula, of which Palmer Land is the southern section, discovered that ice sheets had been retreating since the late 20th century. Ferrigno and her colleagues saw similar, and if anything more striking disappearance in their latest study. “We found that most, if not all, the ice fronts in the study area showed overall retreat,” she explained.

Because the Antarctic Peninsula is the furthest part of the continent from the south pole, it is the most susceptible to variations in temperature. Consequently, dramatic changes seen there are not representative of Antarctica as a whole. “Palmer Land is fairly representative of the Antarctic Peninsula, but not of the Antarctic continent as a whole,” Ferrigno explains. “Although there are changes occurring in other parts of Antarctic, it is not as dramatically visible.”

ce-front retreat in part of the southern Antarctic Peninsula from 1947 to 2009. Credit: US Geological Survey

Ice-front retreat in part of the southern Antarctic Peninsula from 1947 (purple lines) through 1990 (blue lines), 1997 (green lines), 2002 (yellow lines) to 2009 (red lines). Credit: US Geological Survey

The study’s conclusions are based in part on maps drawn of the region as far back as 1949, and then satellite measurements since the 1970s. Despite the possibility of human error in the oldest maps Ferrigno says that the retreat in ice cover is “very clear”. “We evaluated the source materials we used and assigned an accuracy factor to each,” she explained. “Where possible, we cross checked the map information, the aerial photographic information, and the satellite information.”

She says that the 32-page report describing the work shows exactly how certain or uncertain all the measurements are, and the overall loss of ice is plain to see. Taken as a whole, the rapid retreat of ice does look to be a consequence of climate change. “I have been looking at historical and remotely sensed data of Antarctica for more than 30 years,” Ferrigno said. “The major changes in the ice shelves in the Antarctic Peninsula are recent, beginning about 20 years ago, with the change beginning in the north of the Peninsula. When I see this amount of ice melt, the evidence points to warming.”

While the polar regions are among the most affected by climate change, Ferrigno notes that other areas are also already being affected. “There have definitely been dramatic changes in both polar areas, but I have looked at glaciers in other parts of the Earth and found changes happening in many areas,” she said.

Ferrigno’s years researching icy climes have led her to view events such as these dispassionately. “As a scientist, I look at the evidence, and draw a conclusion,” she explains. “The Earth is always changing to a lesser or greater degree in one area or another – change is one of life’s constants.” However, the facts of the situation in Palmer Land can point in only one direction. “Right now, the evidence points to warming affecting the ice of the Antarctic Peninsula,” Ferrigno repeats.

Saturday round-up: Methane menace?

Natalia Shakhova, who led a series of month-long expeditions on icebreakers in the Arctic monitoring methane levels. Credit: Todd Paris, University of Alaska, Fairbanks.

Natalia Shakhova, who led a series of month-long expeditions on icebreakers in the Arctic monitoring methane levels. Credit: Todd Paris, University of Alaska, Fairbanks.

Frozen undersea terrain in the Arctic is warming up and bubbling out massive, previously overlooked, amounts of the greenhouse gas methane. Around eight million tonnes of methane is being produced annually  – roughly equivalent to the total amount of methane that had been thought to be emitted by all the world’s seas.

“Remobilization to the atmosphere of only a small fraction of the methane held in East Siberian Arctic Shelf (ESAS) sediments could trigger abrupt climate warming,” write Natalia Shakhova and colleagues in the journal Science. “It is believed that sub-sea permafrost acts as a lid to keep this shallow methane reservoir in place. The permafrost lid is clearly perforated, and sedimentary methane is escaping to the atmosphere.”

Shakhova and fellow scientists at the University of Alaska, the Russian Academy of Sciences and Stockholm University conducted studies on ice-breaking ships between 2003 and 2008. This was the largest study of methane emissions in the ESAS area ever conducted. The researchers found that most of the area – reaching halfway across the Northern Russian coast – contained more methane than would normally be possible. The team also recorded bubble clouds emerging from the sea. “Taken together, the observations demonstrate that the ESAS—the world’s largest continental shelf sea—is perennially laden with methane all the way up to the sea surface,” the researchers write.

The sea surface above the East Siberian Arctic Shelf is full of ice and bubbles. Sonar is the only way to detect the vast clouds of methane bubbles rising from the seafloor. Photo courtesy of Igor Semiletov, University of Alaska Fairbanks

The sea surface above the East Siberian Arctic Shelf is full of ice and bubbles. Sonar is the only way to detect the vast clouds of methane bubbles rising from the seafloor. Photo courtesy of Igor Semiletov, University of Alaska Fairbanks

While the researchers say that the additional amount of methane produced is large, it is not alarming. With the ESAS being hard to access and measure, it is unclear whether these emissions have begun recently or have been going on for some time. However, they are likely to be accelerated by warming seas. “To discern whether this extensive methane venting over the ESAS is a steadily ongoing phenomenon or signals the start of a more massive methane release period, there is an urgent need for expanded investigations,” the researchers write.

Meanwhile, this week New Scientist reported on a recent Geophysical Research Letters paper showing that ice flow out of the Arctic into a channel between Canada and Greenland reached highs in 2007 and 2008. Ronald Kwok of the Jet Propulsion Laboratory in California, together with researchers from the Danish Meteorological Institute and the University of Copenhagen looked at flows into the Nares Strait between 1997 and 2009. Looking at data from satellites, they noted ice arches forming in two places along the strait usually stop these flows, but one failed to form in 2007, and only briefly stopped the ice in 2008.

The Nares Strait contains some of the thickest ice in the Arctic. The arches that stop it from flowing usually form in late autumn and early winter. They are typically made up from ice that has flowed through earlier in the year, fixed together with more recently frozen material. However, the early year ice flows have been melting to produce ever smaller lumps in the later period of the survey, meaning that it’s harder to form arches. “If there is a decreased likelihood of arch formation as the ice cover becomes thinner and weaker due to warming, there is the potential for the Nares Strait to shift to a higher flow,” Kwok and colleagues write.

Sea change around the icy continent

British Antarctic Survey's Huw Griffiths

British Antarctic Survey's Huw Griffiths

The sea temperature near the West Antarctic Peninsula has risen by 2°C over the past 40 years, and further changes across Antarctica threaten upheaval among the creatures living there. So says the British Antarctic Survey’s Huw Griffiths, who has conducted a wide-ranging review of research in the region. As a marine biologist rather than a specialist climate scientist, Griffiths looked at how global warming has affected and will continue to affect life in the southernmost seas. His study was partly inspired by the Scientific Committee on Antarctic Research (SCAR) report published in November that predicted a 1.4 m sea rise by 2100.

He drew together conclusions from the SCAR figures, British Antarctic Survey (BAS) surveys, and research performed elsewhere. In particular he used the results of a collaboration between the BAS and the University of Bath that combined predictions from 18 different models of how sea ice cover will change over the next 90 years. “All of the models agreed that there’s going to be a reduction of sea ice, and most of them agree strongly where they will be,” Griffiths explained. “If you’ve got less sea ice then there’s less food available, as it’s key for all the plankton blooms.”

Another threat to Antarctic life comes as the oceans absorb CO2, making them more acidic. “Polar regions, because cold water can take up more CO2 than warm water, are at particular risk from ocean acidification,” Griffiths said. “We expect the animals that build their skeletons out of calcium carbonate to do badly, because calcium carbonate becomes limited as the ocean gets acidified.”

The third area that Griffiths looked at suggested that temperatures around the West Antarctic Peninsula are now at a level where warmer water species may invade the traditionally cooler seas. “Even a small change in the species you’ve already got can make a big change in the ecosystem, even without bringing in other species,” he noted.

Griffiths is clearly more at home talking about marine life than what might be causing the changes in marine life that he’s seeing. However, when I asked him to help me with the purpose of my blog – explaining climate change – he said that he was well positioned to describe some of the effects. “Antarctica is one of the best places if you want to observe real changes due to human impact,” he explained. “In the West Antarctic 90% of the glaciers that are on land are retreating. We’ve seen surface waters warming, we’ve seen sea ice reducing every summer. Our physical scientists tell me that it’s linked to human activity, as in the amount of CO2 being released into the atmosphere, directly affecting the temperature and weather systems surrounding the Antarctic.”

While having benefited from personally seeing strong evidence about climate change, the way that some people view the debate on climate change as almost a matter of faith troubles Griffiths. “As a scientist I was always taught to take things on a case by case basis. I look at all the different indicators I’ve listed, and I can see the work behind it.” He says that even if people don’t have this depth of knowledge, it’s “incredibly important” to step back and look at the balance of evidence if presented with one piece that has been discovered to be wrong. “There are so many links between human activity and climate change. As a scientist you can never be 100% sure of your findings – there is always going to be a degree of uncertainty and that can make it difficult for people to understand the full complexities of scientific research. It is also important to remember that scientists base their findings on evidence, rather than belief.”