SCIENCE DISCUSSION ONLY
Moderators: kiore, Blip, The_Metatron
And, well, I write a lot.
But this long piece that just went up at Rolling Stone tries to distill what we now know about climate change into 3 numbers
1) 2 degrees C--that's what the world's nations (even oil states) have agreed is the most we can possibly let temps rise. It's actually too high--but it is the one thing about climate change that the world has agreed on
2) 565 gigatons co2--that's roughly how much more carbon we can pour into the atmosphere between now and 2050 and have a reasonable chance of staying below 2 degrees. It's not much--we burn about 30 gigatons a year, and growing, so at current rates would go by in 16 years
3) 2795 gigatons co2. This is the really scary number. It's how much carbon the fossil fuel industry (and the countries that operate like fossil fuel companies) have already in their reserves. The stuff that props up their share price, lets them borrow money. The stuff they're committed to burning.
What that means is: we now know for certain that the stated business plans of this industry will wreck the planet. It's not even close--they're planning to burn 5 x the carbon that any sane scientist sets as the absolute upper limit.
So stopping them doesn't mean gradual shifts in trajectory. It means taking on this industry with at least as much vigor as we took on companies that did business with apartheid South Africa.
Michael D. Lemonick at Climate Central lets us in on the bad news; climate change will probably cause sea rising to be higher than we thought. So get your snorkel and swim fins ready.A new analysis released Thursday in the journal Science implies that the seas could rise dramatically higher over the next few centuries than scientists previously thought — somewhere between 18-to-29 feet above current levels, rather than the 13-to-20 feet they were talking about just a few years ago.Twenty-nine feet of sea-level rise, by contrast, or even 18, would put hundreds coastal cities around the globe entirely under water, displacing many hundreds of millions of people and destroying untold trillions in property. It would, in short, be a disaster of unimaginable proportions.
[youtube]http://www.youtube.com/watch?v=1KkrlhoFbBM[/youtube]
Thank Pete for scientists. They keep a pretty good tab on the sea ice up in the Arctic. This is a very bookmarkable link (graphs galore). In the late spring there is as much as 15 million square kilometers of sea ice caused by the annual blackout of the Earth's rotation during the northern hemisphere's winter. By the beginning of Autumn, there can be as little as 3 million square kilometers of sea ice due to the sun's exposure to the tilted Earth. 3 million is now the new normal.
As of July 17, the amount of Arctic Sea Ice is below 5 million square kilometers which is earlier than any time before in recorded history. By way of comparison, years 1979 and 1985 spent 45 days (as opposed to 9 days) going from 6 mil sq. K. down to 5 mil. sq.K.
Well, the big problem is that we are well blow the mean ice coverage for this time of year. According to the Arctic Ice blog, we are more than 2 million square miles of ice melt below the mean set between 1979 and 2008. This is the ice melt reality in northern Greenland:
[youtube]http://www.youtube.com/watch?v=RauzduvIYog[/youtube]
All it takes is 1.6 degrees Celius to melt all of the Greenland Ice Sheet.The Greenland ice sheet is likely to be more vulnerable to global warming than previously thought. The temperature threshold for melting the ice sheet completely is in the range of 0.8 to 3.2 degrees Celsius of global warming, with a best estimate of 1.6 degrees above pre-industrial levels, shows a new study by scientists from the Potsdam Institute for Climate Impact Research (PIK) and the Universidad Complutense de Madrid. Today, already 0.8 degrees of global warming has been observed. Substantial melting of land ice could contribute to long-term sea-level rise of several meters and therefore it potentially affects the lives of many millions of people.
NASA wrote:
For several days this month, Greenland's surface ice cover melted over a larger area than at any time in more than 30 years of satellite observations. Nearly the entire ice cover of Greenland, from its thin, low-lying coastal edges to its two-mile-thick center, experienced some degree of melting at its surface, according to measurements from three independent satellites analyzed by NASA and university scientists.
Arctic sea ice extent measured by the National Snow and Ice Data Center (NSIDC) set a new record minimum today. All doubt is gone that 2012 will obliterate all the old record lows on sea ice area, extent and volume. The NSIDC uses 5 day averaging to reduce noise, so it responds more slowly than other measures. The University of Washington's PIOMAS sea ice thickness results are released on a monthly basis, so they will report record low volume results, that have surely already been set, in September.
NASA MODIS false color summer 2012 sea ice collapse animation assembled by Neven
Melting and erosion of permafrost along Siberia's vast Arctic coastline is releasing huge amounts of CO2, about ten times more than previously estimated, to the atmosphere. The "Ancient Ice Complex" that crops out along the 7000 kilometer long Siberian coastline has melted and eroded more quickly than expected as the climate warmed 2 degrees Celsius faster than models predicted. Measurements combined with computer models calculated that44 ± 10 teragrams of old carbon is activated annually from Ice Complex permafrost, an order of magnitude more than has been suggested by previous studies.
About two thirds of this carbon becomes atmospheric CO2 and one third is reburied in marine sediment.
AS ARCTIC sea ice hits a record low, scientific focus is turning to climate ''tipping points'' - a threshold that, once crossed, cannot be reversed and will create fundamental changes to other areas.
''It's a trigger that leads to more warming at a regional level but also leads to flow-on effects through other systems,'' Will Steffen, the chief adviser on global warming science to Australia's Climate Commission, said.
There are about 14 known ''tipping elements'', according to a paper published by the US Proceedings of the National Academy of Sciences.
Read more: http://www.smh.com.au/environment/clima ... z27I8jcVlI
YOU may not have felt it, but the whole world shuddered on 11 April, as Earth's crust began the difficult process of breaking a tectonic plate. When two huge earthquakes ripped through the floor of the Indian Ocean, they triggered large aftershocks on faults the world over, and provided the best evidence yet that the vast Indo-Australian plate is being torn in two.
DavidMcC wrote:This could also be bad news for the climate in the long term:
http://www.newscientist.com/article/mg21528843.500-earth-cracking-up-under-indian-ocean.htmlYOU may not have felt it, but the whole world shuddered on 11 April, as Earth's crust began the difficult process of breaking a tectonic plate. When two huge earthquakes ripped through the floor of the Indian Ocean, they triggered large aftershocks on faults the world over, and provided the best evidence yet that the vast Indo-Australian plate is being torn in two.
As carbon dioxide levels in the atmosphere continue to climb, most climate models project that the world’s oceans and trees will keep soaking up more than half of the extra CO2. But researchers report this week that the capacity for land plants to absorb more CO2 will be much lower than previously thought, owing to limitations in soil nutrients1.
...
Just Wondering wrote:DavidMcC wrote:This could also be bad news for the climate in the long term:
http://www.newscientist.com/article/mg21528843.500-earth-cracking-up-under-indian-ocean.htmlYOU may not have felt it, but the whole world shuddered on 11 April, as Earth's crust began the difficult process of breaking a tectonic plate. When two huge earthquakes ripped through the floor of the Indian Ocean, they triggered large aftershocks on faults the world over, and provided the best evidence yet that the vast Indo-Australian plate is being torn in two.
! |
GENERAL MODNOTE FYI, changes have been implemented: http://www.rationalskepticism.org/feedb ... l#p1500883 This thread will be strictly moderated, and restricted to discussion - pro and con - on climate change science. Non-science posts may be binned, and repeatedly posting OT comments or denial may incur sanctions. A denial thread has been designated for that purpose: http://www.rationalskepticism.org/post1 ... l#p1472022 |
Run-off from Greenland may weaken carbon sink
* 17:41 11 October 2012 by Michael Marshall
* For similar stories, visit the Climate Change Topic Guide
More fresh water isn't always a good thing. The volume of fresh water gushing into the Atlantic from Greenland has increased in the past few decades. The water will interfere with Atlantic currents and may even reduce the ocean's ability to store carbon.
"Greenland has been losing increasing amounts of mass," says Jonathan Bamber of the University of Bristol in the UK. What had been unclear was how much of that was due to losing water to the ocean, as opposed to factors like reduced snowfall.
Bamber and his colleagues have reconstructed the freshwater losses from Greenland from 1958 to 2010. The losses have accelerated since the early 1990s, particularly around the southern tip of the island. The south-east has seen losses rise by 50 per cent in less than 20 years.
Dumping fresh water into the North Atlantic could weaken the Atlantic Meridional Overturning Circulation (AMOC), the vast "conveyor belt" current that carries warm tropical water to northern Europe. It has been suggested that Europe will get colder as a result, but that is unlikely to happen, at least in the next few decades. "That was all blown out of proportion," says Ruth Curry of the Woods Hole Oceanographic Institution in Massachusetts.
The polar oceans are among the world's most important carbon sinks, taking in carbon dioxide from the air and trapping it in their depths – and that could change as a result of the freshwater flux. Curry says Greenland's fresh water will remain at the surface, since the weakened AMOC will be slow to carry it to the bottom. That also means that once this fresh water has absorbed as much carbon dioxide as it can hold, it will not be replaced at the surface by carbon-dioxide-free water that could absorb more of the gas.
"If you slow the AMOC, you're decreasing the ability of the ocean to take up carbon dioxide," Curry says. Weakening the carbon sink like this could speed up global warming even further.
HadCRUT is underpinned by observations and we've previously been clear it may not be fully capturing changes in the Arctic because we have had so little data from the area.
Global Highlights
The average combined global land and ocean surface temperature for June 2012 was 0.63°C (1.13°F) above the 20th century average of 15.5°C (59.9°F). This is the fourth warmest June since records began in 1880.
The Northern Hemisphere land surface temperature for June 2012 was the all-time warmest June on record, at 1.30°C (2.34°F) above average.
The globally-averaged land surface temperature for June 2012 was also the all-time warmest June on record, at 1.07°C (1.93°F) above average.
ENSO-neutral conditions continued in the eastern equatorial Pacific Ocean during June 2012 as sea surface temperature anomalies continued to rise. The June worldwide ocean surface temperatures ranked as the 10th warmest June on record.
The combined global land and ocean average surface temperature for January–June 2012 was the 11th warmest on record, at 0.52°C (0.94°F) above the 20th century average.
The Northern Hemisphere land surface temperature for June 2012 was the all-time warmest June on record, at 1.30°C (2.34°F) above average.
Users viewing this topic: No registered users and 1 guest