Starship Asterisk*

http://earthobservatory.nasa.gov/IOTD/view.php?id=76377 wrote:

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<<Greenland’s Jakobshavn glacier has the potential to influence sea level rise more than any other single feature in the Northern Hemisphere. Like a funnel, the large glacier channels ice from much of the Greenland ice sheet into the Atlantic Ocean, at a rate of about 15 kilometers per year. It is the world’s fastest flowing glacier.

Why do some glaciers, like Jakobshavn, feed ice into the ocean so quickly while others barely move at all? Answering that question is crucial because if we are to predict how much sea levels will rise as Earth warms, we have to know how much ice glaciers will deliver to the ocean. The key to predicting glacier flow is to map the ground beneath the ice—a concept described in the Earth Observatory’s new feature, IceBridge: Building a record of Earth’s changing ice, one flight at a time.

• The shape of the land where a glacier meets the ocean influences how the glacier will behave, says Sophie Nowicki, a scientist at NASA's Goddard Space Flight Center who studies ice sheets using computer models. If the ground slopes downhill as you move inland from the ocean—or if the glacier is channeled through a deep canyon or fjord—then it’s a sure bet that the glacier will retreat quickly. In contrast, bumps or ridges beneath the glacier can act as pinning points and stop the retreat.

Jakobshavn, it turns out, flows through a deep canyon. The image on the right shows the shape of Jakobshavn’s bed based on radar measurements made by an instrument now flying on airplanes as part of NASA’s IceBridge mission. The instrument made these measurements on earlier flights, but additional flights on IceBridge continue to refine the picture. Dark blue reveals the deep channel through which Jakobshavn flows.

• “Before IceBridge, this measurement of Jakobshavn was the best bed we had,” says Nowicki, pointing to a crude figure (image left) illustrating what was once the best picture of the ground beneath any glacier. “With much more data from the radar instrument (on IceBridge and earlier flights), we realized that the bed of Jakobshavn Isbrae is a channel that could be compared to the Grand Canyon. It’s the same width, the same depth.” Ice-flow models that use the new measurements of the Jakobshavn bed now match pretty closely with the real-world observations of its movements.

Because the new bed measurements improve ice-flow models, they will also help scientists understand how much ice could contribute to sea level rise in the future. With regular flights over the next six years, IceBridge will map out glacier beds throughout Greenland and Antarctica.>>

Carbon dioxide levels in the atmosphere have broken through a symbolic mark.
Daily measurements of CO2 at a US government agency lab on Hawaii have topped 400 parts per million for the first time. The station, which sits on the Mauna Loa volcano, feeds its numbers into a continuous record of the concentration of the gas stretching back to 1958. The last time CO2 was regularly above 400ppm was three to five million years ago - before modern humans existed. Scientists say the climate back then was also considerably warmer than it is today. Carbon dioxide is regarded as the most important of the manmade greenhouse gases blamed for raising the temperature on the planet over recent decades. Human sources come principally from the burning of fossil fuels such as coal, oil and gas. The usual trend seen at the volcano is for the CO2 concentration to rise in winter months and then to fall back as the northern hemisphere growing season kicks in. Forests and other vegetation pull some of the gas out of the atmosphere. This means the number can be expected to decline by a few ppm below 400 in the coming weeks. But the long-term trend is upwards.

Carbon by proxy

James Butler is responsible for the Earth System Research Laboratory, a facility on Mauna Loa belonging to the National Oceanic and Atmospheric Administration (Noaa). Its daily average CO2 concentration figure on Thursday was 400.03. Dr Butler told BBC News: "Carbon dioxide has some variability on an hourly, daily and weekly basis, so we are not comfortable calling a single number - the lowest we will go is on a daily average, which has happened in this case. "Mauna Loa and the South Pole observatory are iconic sites as they have been taking CO2 measurements in real time since 1958. Last year, for the first time, all Arctic sites reached 400ppm. "This is the first time the daily average has passed 400ppm at Mauna Loa."
The long-term measurements at Mauna Loa were started by a Scripps Institution of Oceanography scientist called Charles Keeling. In 1958, he found the concentration at the top of the volcano to be around 315ppm (that is 315 molecules of CO2 for every one million molecules in the air). Every year since then, the "Keeling Curve", as it has become known, has squiggled resolutely higher. Scripps still operates equipment alongside Noaa on the mountain peak. Its readings have been pushing 400ppm in recent days, and on Thursday recorded a daily average of 399.73.
But Noaa senior scientist Pieter Tans said: "Our measurements (Noaa) are in Coordinated Universal Time, while the Keeling measurements are in local Hawaii time. If you shift the Keeling definition of a day to the same as ours then we do agree almost completely on the measurements." By this definition, the Keeling team's Thursday number would be 400.08ppm.
And Dr Butler added: "Probably next year, or the year after that, the average yearly reading will pass 400pm. "A couple of years after that, the South Pole will have readings of 400ppm, and in eight to nine years we will probably have seen the last CO2 reading under 400ppm." To determine CO2 levels before the introduction of modern stations, scientists must use so-called proxy measurements. These include studying the bubbles of ancient air trapped in Antarctic ice. One of these can be used to describe CO2 levels over the past 800,000 years. It suggests that CO2 held steady over this longer period at between 200ppm and 300ppm. British atmospheric physicist Prof Joanna Haigh commented: "In itself, the value 400ppm of CO2 has no particular significance for the physics of the climate system: concentration levels have been in the 300s for so long and now we've passed the 400 mark. However, this does give us the chance to mark the ongoing increase in CO2 concentration and talk about why it's a problem for the climate."

Carbon dioxide in atmosphere did not break 400 ppm at Hawaii site
Carbon dioxide measurements in the Earth's atmosphere did not break the symbolic milestone of 400 parts per million at a Hawaiian observatory last week, according to a revised reading from the nation's climate observers.


The National Oceanic and Atmospheric Administration (NOAA) revised its May 9 reading at the Mauna Loa observatory in Hawaii, saying it remained fractions of a point below the level of 400 ppm, at 399.89.

BMAONE23 wrote:

http://www.latimes.com/news/science/sciencenow/la-sci-sn-carbon-dioxide-400-20130513,0,7196126.story wrote:
Carbon dioxide measurements in the Earth's atmosphere did not break the symbolic milestone of 400 parts per million at a Hawaiian observatory last week, according to a revised reading from the nation's climate observers.

The National Oceanic and Atmospheric Administration (NOAA) revised its May 9 reading at the Mauna Loa observatory in Hawaii, saying it remained fractions of a point below the level of 400 ppm, at 399.89.

BMAONE23 wrote:LA Times reports NOAA revises number

[url=http://keelingcurve.ucsd.edu/][b][i]The Keeling Curve,[/i][/b][/url] [i]measuring atmospheric carbon dioxide since 1958. The trend is fairly obvious. [b](Photo by Scripps Institute/UCSD)[/b][/i]

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On May 9, 2013, atmospheric levels of carbon dioxide hit a new record high. Announced by the National Oceanic and Atmospheric Administration, the levels of CO₂ in the air on that day^* reached a daily average of 400 parts per million (ppm). This is the highest level of atmospheric CO₂ in human history, and in fact the highest level for at least 800,000 years. It gets worse: the amount of CO₂ in the air likely hasn’t been this high since the Pliocene Epoch, more than three million years ago.
...
The simple truth is this: More carbon dioxide is in the air than there has been for millions of years. The world is warming up, and it’s due to human influence. If we do nothing it’ll continue to rise, and even if we get our act together it’ll get worse before it gets better.

• The NOAA is reporting the May 9 level as 400.03, while the Scripps site reports it as 399.73. Part of that is due to simple time-of-day cutoffs, but since the 400 level is somewhat arbitrary anyway, it’s a quibble.

neufer wrote:

BMAONE23 wrote:

http://www.latimes.com/news/science/sciencenow/la-sci-sn-carbon-dioxide-400-20130513,0,7196126.story wrote:
Carbon dioxide measurements in the Earth's atmosphere did not break the symbolic milestone of 400 parts per million at a Hawaiian observatory last week, according to a revised reading from the nation's climate observers.

The National Oceanic and Atmospheric Administration (NOAA) revised its May 9 reading at the Mauna Loa observatory in Hawaii, saying it remained fractions of a point below the level of 400 ppm, at 399.89.

We can all breath a little easier

emc wrote:our atmosphere should be called easier… maybe there would be less stress on the planet

Beyond wrote: ED, have you been nibbling on some 'loco-weed'

by emc
our atmosphere should be called easier… maybe there should be less stress on the planet

mjimih wrote:
I think after we're gone the plants and oceans would rectify the situation to pre industrial levels right? I can't find a study describing how fast or by how much though. Too many websites to look through, anyone?

Ecological consequences
Should a substantial amount of the carbon enter the atmosphere, it would accelerate planetary warming. A significant proportion will emerge as methane, which is produced when the breakdown occurs in lakes or wetlands. Although it does not remain in the atmosphere for long, methane traps more of the sun’s heat. The potential for large methane emissions in the Arctic is poorly understood. The United States Department of Energy and the European Union recently committed to related research projects. Preliminary computer analyses suggest that permafrost could produce carbon equal to 15 percent or so of today’s emissions from human activities

mjimih wrote:
And methane? How does that stuff breakdown. Potentially a lot of it could start bubbling up out of ocean floors or from all those permafrost areas starting to get mushy. Hard to judge as the chart here seems to show a slowdown as of 2005?

mjimih wrote:I think after we're gone the plants and oceans would rectify the situation to pre industrial levels right?

Artificial trees

A notable example of an atmospheric scrubbing process are the artificial trees. This concept, proposed by climate scientist Wallace S. Broecker and science writer Robert Kunzig, imagines huge numbers of artificial trees around the world to remove ambient CO2. The technology is now being pioneered by Klaus Lackner, a researcher at the Earth Institute, Columbia University, whose artificial tree technology can suck up to 1,000 times more CO2 from the air than real trees can, at a rate of about one ton of carbon per day if the artificial tree is approximately the size of an actual tree. The CO2 would be captured in a filter and then removed from the filter and stored.

Beyond wrote:Well, there goes unemployment. It's going to take a ghastly amount of people to decarbonize these carbon collectors and deal with the carbon that was collected.

mjimih wrote:

Beyond wrote:
Well, there goes unemployment.

It's going to take a ghastly amount of people to decarbonize these carbon collectors and deal with the carbon that was collected.