New Research

[BornFromTheVoid]

Strong atmospheric chemistry feedback to climate warming from Arctic methane emissions

 

The magnitude and feedbacks of future methane release from the Arctic region are unknown. Despite limited documentation of potential future releases associated with thawing permafrost and degassing methane hydrates, the large potential for future methane releases calls for improved understanding of the interaction of a changing climate with processes in the Arctic and chemical feedbacks in the atmosphere. Here we apply a “state of the art†atmospheric chemistry transport model to show that large emissions of CH4 would likely have an unexpectedly large impact on the chemical composition of the atmosphere and on radiative forcing (RF). The indirect contribution to RF of additional methane emission is particularly important. It is shown that if global methane emissions were to increase by factors of 2.5 and 5.2 above current emissions, the indirect contributions to RF would be about 250% and 400%, respectively, of the RF that can be attributed to directly emitted methane alone. Assuming several hypothetical scenarios of CH4 release associated with permafrost thaw, shallow marine hydrate degassing, and submarine landslides, we find a strong positive feedback on RF through atmospheric chemistry. In particular, the impact of CH4 is enhanced through increase of its lifetime, and of atmospheric abundances of ozone, stratospheric water vapor, and CO2 as a result of atmospheric chemical processes. Despite uncertainties in emission scenarios, our results provide a better understanding of the feedbacks in the atmospheric chemistry that would amplify climate warming.

 

http://onlinelibrary.wiley.com/doi/10.1029/2010GB003845/abstract

[knocker]

Airborne Radar Looking Through Thick Ice During NASA Polar Campaigns

 

The bedrock hidden beneath the thick ice sheets covering Greenland and Antarctica has intrigued researchers for years. Scientists are interested in how the shape of this hidden terrain affects how ice moves -- a key factor in making predictions about the future of these massive ice reservoirs and their contribution to sea level rise in a changing climate.

 

NASA has been monitoring Antarctic and Arctic ice since 2009 with the Operation IceBridge airborne mission. Although the primary objective is to continue the data record of ice sheet surface elevation changes from NASA's Ice, Cloud and Land Elevation Satellite, or ICESat, which stopped functioning in 2009, IceBridge is also gathering data on other aspects of polar ice from snow on top to the bedrock below.  One radar instrument on these flights that is currently headed to Antarctica for another year of observations is revealing insights about the bedrock hidden beneath the ice sheet.

 

http://www.nasa.gov/content/goddard/airborne-radar-looking-through-thick-ice-during-nasa-polar-campaigns/#.Upz5c-KFdnk

Edited December 2, 2013 by knocker

[knocker]

Arctic Ocean glacial history ( open Access)

 

Abstract

While there are numerous hypotheses concerning glacial–interglacial environmental and climatic regime shifts in the Arctic Ocean, a holistic view on the Northern Hemisphere's late Quaternary ice-sheet extent and their impact on ocean and sea-ice dynamics remains to be established. Here we aim to provide a step in this direction by presenting an overview of Arctic Ocean glacial history, based on the present state-of-the-art knowledge gained from field work and chronological studies, and with a specific focus on ice-sheet extent and environmental conditions during the Last Glacial Maximum (LGM). The maximum Quaternary extension of ice sheets is discussed and compared to LGM. We bring together recent results from the circum-Arctic continental margins and the deep central basin; extent of ice sheets and ice streams bordering the Arctic Ocean as well as evidence for ice shelves extending into the central deep basin. Discrepancies between new results and published LGM ice-sheet reconstructions in the high Arctic are highlighted and outstanding questions are identified. Finally, we address the ability to simulate the Arctic Ocean ice sheet complexes and their dynamics, including ice streams and ice shelves, using presently available ice-sheet models. Our review shows that while we are able to firmly reject some of the earlier hypotheses formulated to describe Arctic Ocean glacial conditions, we still lack information from key areas to compile the holistic Arctic Ocean glacial history.

 

http://www.sciencedirect.com/science/article/pii/S0277379113002989

[knocker]

Simulations of Hurricane Katrina (2005) under sea level and climate conditions for 1900

 

Abstract

Global warming may result in substantial sea level rise and more intense hurricanes over the next century, leading to more severe coastal flooding. Here, observed climate and sea level trends over the last century (c. 1900s to 2000s) are used to provide insight regarding future coastal inundation trends. The actual impacts of Hurricane Katrina (2005) in New Orleans are compared with the impacts of a similar hypothetical hurricane occurring c. 1900. Estimated regional sea level rise since 1900 of 0.75 m, which contains a dominant land subsidence contribution (0.57 m), serves as a ‘prototype’ for future climate-change induced sea level rise in other regions. Landform conditions c. 1900 were estimated by changing frictional resistance based on expected additional wetlands at lower sea levels. Surge simulations suggest that flood elevations would have been 15 to 60 % lower c. 1900 than the conditions observed in 2005. This drastic change suggests that significantly more flood damage occurred in 2005 than would have occurred if sea level and climate conditions had been like those c. 1900. We further show that, in New Orleans, sea level rise dominates surge-induced flooding changes, not only by increasing mean sea level, but also by leading to decreased wetland area. Together, these effects enable larger surges. Projecting forward, future global sea level changes of the magnitude examined here are expected to lead to increased flooding in coastal regions, even if the storm climate is unchanged. Such flooding increases in densely populated areas would presumably lead to more widespread destruction.

 

http://link.springer.com/article/10.1007%2Fs10584-013-1011-1

[knocker]

Quite interesting.

 

Knowing the unknowns

 

Abstract

The Earth's atmosphere is not the only source of radiative forcing and anthropogenic climate change. As surely as people and civilizations have carbon footprints, they have albedo footprints as well. By altering the reflectivity of roughly half the land surface of the Earth in the past, mankind has made inadvertent geoengineering a part of the landscape of history. This worldwide alteration of reflectivity raises questions about the future of climate change, for albedo is a first-order determinant of the Earth's radiative equilibrium. As surfaces absorb roughly 100 times more solar energy than the atmosphere, future anthropogenic changes in both land and water albedo may figure significantly in climate policy outcomes.

 

http://onlinelibrary.wiley.com/doi/10.1002/2013EF000151/pdf

Edited December 8, 2013 by knocker

[Gray-Wolf]

There does seem some reluctance, from some quarters, to explore just how long we have impacted our planet and how such impacts have 'altered' past climate.

 

The folk who try and downplay the role of CO2 on our climate appear to take real issue at any past 'human influenced' fluctuations in CO2 levels. The draw down of CO2 around the time of the European plagues and Meso American depopulation must never be associated with 'global cooling' over the same period ( nor any CO2 anomalies during the expansion of the Roman empire or after the introduction of farming practices into the world) as it would highlight just how impacting our current massive outpourings of CO2 must be?

 

The same will be true of man made albedo change and possible climate impacts as it will only serve to highlight the impacts of the current albedo flip across the north and the climate changes that will bring to us?

[knocker]

Understanding sea level: Ways forward from the past

 

http://www.pages-igbp.org/download/docs/newsletter/2009-2/PAGESnews-2009-2_low-res.pdf

[mikeworst]

Bit out of date, huh?

[knocker]

Bit out of date, huh?

 

I take it from that you are saying the paper has no validity as it's three years old, huh? In that case we had better ignore any papers published before last week.

Edited December 9, 2013 by knocker

[mikeworst]

I take it from that you are saying the paper has no validity as it's three years old, huh? In that case we had better ignore any papers published before last week.

 Ummm it is not a paper.

[Gray-Wolf]

Ooooh!, you are a coy boy! C'mon, tell us, what is your issue with them?

 

I read through them all again and am struggling to see where time has done anything but firm up our views on the subject matter contained?

 

Surely one Four a Forum is enough? (LOL)

[knocker]

I haven't had chance to read this but it seems unduly pessimistic at first glance. I've got an idea it's been posted before.

 

The Future of Arctic Sea Ice

 

Arctic sea ice is a key indicator of the state of global climate because of both its sensitivity to warming and its role in amplifying climate change. Accelerated melting of the perennial sea ice cover has occurred since the late 1990s, which is important to the pan-Arctic region, through effects on atmospheric and oceanic circulations, the Greenland ice sheet, snow cover, permafrost, and vegetation. Such changes could have significant ramifications for global sea level, the ocean thermohaline circulation, native coastal communities, and commercial activities, as well as effects on the global surface energy and moisture budgets, atmospheric and oceanic circulations, and geosphere-biosphere feedbacks. However, a system-level understanding of critical Arctic processes and feedbacks is still lacking. To better understand the past and present states and estimate future trajectories of Arctic sea ice and climate, we argue that it is critical to advance hierarchical regional climate modeling and coordinate it with the design of an integrated Arctic observing system to constrain models.

 

http://www.annualreviews.org/doi/pdf/10.1146/annurev-earth-042711-105345

[knocker]

Gavin Schmidt.

 

I thought this would be a little silly, but it's actually pretty good: Climate simulations of Middle Earth:

 

 

Scientists simulate the climate of Tolkien’s Middle Earth

Ever wondered what the weather and climate was like in Middle Earth, the land of hobbits, dwarves, elves and orcs, from J.R.R. Tolkien’s The Hobbit and The Lord of the Rings? Climate scientists from the University of Bristol, UK have used a climate model, similar to those used in the recent Intergovernmental Panel on Climate Change (IPCC) report, to simulate and investigate the climate of Middle Earth.

 

The results show that The Shire, where the hobbit Bilbo Baggins lived before he was whisked away on his unexpected adventure described in The Hobbit, had a climate very similar to that of Lincolnshire and Leicestershire in the UK. However, Mordor, the land of the evil Sauron, had a climate similar to that of Los Angeles and western Texas.

 

The results are presented in a paper, penned by the wizard Radagast the Brown (probably the first environmental scientist). Among other findings, he explains why the elves set sail from the Grey Havens (the prevailing winds were favourable for their journey to the West), and the existence of a dry climate east of the Misty Mountains (the mountains cast a rain-shadow over the region). Radagast also discusses the strengths and weaknesses of contemporary climate models, and shows how they can be used to understand and predict future climate.

 

Professor Richard Pancost, Director of the Cabot Institute at the University of Bristol said: “Because climate models are based on fundamental scientific processes, they are able not only to simulate the climate of the modern Earth, but can also be easily adapted to simulate any planet, real or imagined, so long as the underlying continental positions and heights, and ocean depths are known.â€

 

Dr Dan Lunt added: “This work is a bit of fun, but it does have a serious side. A core part of our work here in Bristol involves using state-of-the-art climate models to simulate and understand the past climate of our Earth. By comparing our results to evidence of past climate change, for example from tree rings, ice cores, and ancient fossils of plants and animals, we can validate the climate models, and gain confidence in the accuracy of their predictions of future climate.â€

 

The IPCC, including several scientists from the University of Bristol, have shown that climate models can successfully simulate climates from the freezing world of the last Ice Age, to the intense warmth of the ‘Eocene greenhouse’, 50 million years ago. These same models are then used to simulate the future climate of our planet.

 

http://www.bristol.ac.uk/university/media/press/10013-english.pdf

Edited December 10, 2013 by knocker

[Coast]

Weather 'behind ozone hole changes'

 

Scientists have been puzzled why the hole, which forms each year over Antarctica, has been changing considerably in size from year to year. Now Nasa researchers say it is the weather that is primarily driving this variability - not the ozone-destroying chemicals in the upper atmosphere. The findings were presented at the American Geophysical Union Fall Meeting in San Francisco.

 

Susan Strahan, from Nasa’s Goddard Space Center in Maryland, said: “We want to measure and see that the ozone hole is being reduced. “But to understand if the ozone hole is shrinking, we need to understand all of the different factors that cause the ozone hole area and depth to vary.†Twenty years ago, the international Montreal Protocol came into force to phase out ozone-depleting substances such as CFCs.  These chemicals break down in the high atmosphere and release chlorine, which, in a reaction driven by the Sun, goes on to destroy ozone gas. As a result, each year, the ozone layer over the southern polar region experiences a deep thinning. After the ban, this hole stopped getting bigger. However, there have not yet been signs of a full recovery – and damaging ultraviolet rays from the Sun are still streaming through.

 

And in some years, such as 2006 and 2011, the hole appeared to be very large, while in others, such as 2012, it looked small. Now scientists from Nasa believe that the weather plays a much more significant role in the complex system than had previously been suggested. Dr Strahan said: “We have identified another factor that wasn’t fully recognised before: and that is how much ozone gets brought to the polar regions in the first place, by the winds.† Satellite images show that fluctuating air temperatures and winds change the amount of ozone gas that sits above Antarctica.  And scientists believe this is dictating the apparent size of the ozone hole changes year on year.

 

If more ozone is brought to the lower region in the stratosphere, there is more ozone to destroy and the hole can look bigger. This was the scenario in 2006. But in 2011, the winds brought less ozone to this lower area, so the ozone there got destroyed more quickly – again the hole looked more sizeable. If, however, as in 2012, the winds push more ozone into the upper stratosphere, this can mask the hole below and make it look smaller.

 

“At the moment, it is winds and temperatures that are really controlling how big it is,†Dr Strahan added. The team thinks meteorological conditions will continue to be the dominant driver in the process until about 2030.  After that, as the long-lasting chemicals in the atmosphere finally start to clear, the layer should start to recover.  Dr Strahan said: “We can project how quickly we think chlorine will decline in the coming decades and use this, as well as our knowledge of temperatures in Antarctica, to predict that the ozone hole will probably go away in 2070, give or take 10 years.â€

 

 

http://www.bbc.co.uk/news/science-environment-25344563

[mikeworst]

The ozone hole has in all likely-hood always been there. They do not know either way do they? I think it is arrogant to use "  think, should, think again, and again,should,predict and probably when they do not have a clue what is going on. It is however safe for their credibility to predict the hole going away in 60 or 70 years is it not.

[jonboy]

The ozone hole has in all likely-hood always been there. They do not know either way do they? I think it is arrogant to use "  think, should, think again, and again,should,predict and probably when they do not have a clue what is going on. It is however safe for their credibility to predict the hole going away in 60 or 70 years is it not.

 

Agree Mike I have found little research on the ozone generation cycle. We do know that ozone is formed bythe interaction of O2 with ultra violet light of given wave lenghth etc which makes you think that if there is a variation in that input then the amount of ozone would naturally vary and if again this change is in line with the strength of solar cycles then what is the greater impact man or natural cycle. To many variables at this time in my opinion to be making such claims about when or even if ozone holes or otherwise will disappear.

[BornFromTheVoid]

The ozone hole has in all likely-hood always been there. They do not know either way do they? I think it is arrogant to use "  think, should, think again, and again,should,predict and probably when they do not have a clue what is going on. It is however safe for their credibility to predict the hole going away in 60 or 70 years is it not.

 

I take it that you at least accept the role of CFCs in ozone depletion, yes?

Predicting how the ozone hole will change on a year to year basis is strongly linked to our ability to predict large scale atmospheric circulation patterns (Brewer Dobson Circulation and others), which as we know, ain't great! Because we're learning more about how the year to year variability works, doesn't negate the fact that CFCs destroyed a lot of ozone, or that when CFC levels drop significantly, the ozone hole will gradually shrink.

[knocker]

The ozone hole has in all likely-hood always been there. They do not know either way do they?

 

They do know it wasn't there in the 50s, 60s and 70s and suddenly appeared with the advent of CFCs and Molina & Rowland (1974) pointed out that CFCs transported into the stratosphere would be photolysed to yield reactive chlorine, which in turn would destroy ozone. Which it then went on to do. Another damn coincidence.

 

http://forum.netweather.tv/topic/64332-antarctic-ice-discussion/page-35#entry2861164

[Gray-Wolf]

Hi JB!

 

Like AGW itself it is never 'all or nothing'? it has to be the interaction of the human forcing with the established natural order ( and the upsets this drives).

 

We know that our chemicals have the potential to destroy ozone and so surely we expect to see this out in nature once we release such chemicals into the atmosphere? We also understood that nature had it's own way of messing with Ozone. Why would we seek to dismiss the 'extra' forcing man has provided in Ozone destruction just because our understanding of 'nature' is growing?

[jonboy]

They do know it wasn't there in the 50s, 60s and 70s and suddenly appeared with the advent of CFCs and Molina & Rowland (1974) pointed out that CFCs transported into the stratosphere would be photolysed to yield reactive chlorine, which in turn would destroy ozone. Which it then went on to do. Another damn coincidence.

 

http://forum.netweather.tv/topic/64332-antarctic-ice-discussion/page-35#entry2861164

 

Ok but.... CFCs may well have a role in reducing ozone and certainly the theory and research would suggest that however if there was a significant decrease in ozone production and transportation at that same time is it little wonder we then saw an increasingly large ozone hole over the southern hemisphere. Before you ask I cannot prove this point as I have found little research on ozone production but to my simple mind we need to consider both sides of the equation before we can come to a conclusion

[jonboy]

Hi JB!

 

Like AGW itself it is never 'all or nothing'? it has to be the interaction of the human forcing with the established natural order ( and the upsets this drives).

 

We know that our chemicals have the potential to destroy ozone and so surely we expect to see this out in nature once we release such chemicals into the atmosphere? We also understood that nature had it's own way of messing with Ozone. Why would we seek to dismiss the 'extra' forcing man has provided in Ozone destruction just because our understanding of 'nature' is growing?

 

I never said its all or nothing but if you put all your eggs in one basket and you find your basket has a major flaw then you run the risk of losing all your eggs.One could argue we are beggining to see this effect with yet another major offshore wind farm scheme being cancelled today. Rather than just saying we need to go green because the planet is warming we should have been saying in both environmental and likely running out of oil terms we need to change our dependency on oil and gas as our main energy source. With this percieved pause then the discussion has been sidelined by cost rather than benefit.

If you look at the small number of posts I do make you will see I am firmly in the skeptic camp that doesn't mean I don't think that the planet will not warm again but personally I don't think we will see this again before 2050/60 and I do believe it will by 2100 be around 2 to 3 degree warmer In my opinion poor arguements lose key oppourtunities to make progress.

[Polar Maritime]

Researchers at the University of Toronto have, for the first time, detected a greenhouse gas in the atmosphere known as perfluorotributylamine (PFTBA, for short and for sanity!). PFTBA has an 100 year global warming potential of 7,100- meaning that a solitary PFTBA molecule has the equivalent warming impact of 7,100 molecules of CO2!!

This is, to my knowledge, the highest potential to affect climate of all known chemicals to date.

The researchers measured the concentration of PFTBA in the atmosphere to be around 0.18 parts per trillion; trace amounts. On the downside, they also discovered that it is long lived in the atmosphere, taking up to 500 years to be removed.

The chemical has been used since the mid 1900’s; mainly in electrical equipment and to date there is no policy in place regulating its use.

The researchers are hopeful that more analysis will follow and that relevant legislation will be put in place regulating its use and subsequently safeguarding our fragile environment.

The study was published online Nov. 27 in the journal Geophysical Research Letters which can be found here:http://onlinelibrary.wiley.com/doi/10.1002/2013GL058010/suppinfo

 

For those without journal access, the press release can be found here:http://media.utoronto.ca/media-releases/arts/new-long-lived-greenhouse-gas-discovered-by-university-of-toronto-chemistry-team/

 

 

[Gray-Wolf]

This also raises the potential of us discovering 'new' pollutants, used in modern processing, that are far more powerful than CO2. If we thought the discovery of the damage CFC's had done over the short time we had used them was nasty then maybe we should be mindful of future shocks from our polluting ways?.

Edited December 15, 2013 by Gray-Wolf

[jonboy]

This also raises the potential of us discovering 'new' pollutants, used in modern processing, that are far more powerful than CO2. If we thought the discovery of the damage CFC's had done over the short time we had used them was nasty then maybe we should be mindful of future shocks from our polluting ways?.

 

And you never know GW we might actually find out CO2 isn't the great evil and that CFC's and other pollutants don't have the the catastophic influence on our atmosphere that the 'THEORIES' and 'MODELS' would have us believe 

[knocker]

And you never know GW we might actually find out CO2 isn't the great evil and that CFC's and other pollutants don't have the the catastophic influence on our atmosphere that the 'THEORIES' and 'MODELS' would have us believe 

 

What was theoretical about the Ozone Hole? I take it then you have another explanation that you are about to share, not only with us but also a couple of Nobel prize winners.