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Athanasia Nikolaou

Interview with an IPCC leading author - 1 views

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    CliSAP: Mr. Held, several hundred researchers worked for several years on preparing the recently published third part of the Assessment Report, without pay and on top of their normal duties. The result was a work over two thousand pages long. Was it worth it?

    An overview of the uncertainties when it comes to estimating investments in low carbon. Maybe there is room for computational management projects in there?
Thijs Versloot

New UN Climate Report published #IPCC - 0 views

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    .. We're doomed ...
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    Most likely
Athanasia Nikolaou

The weather of 2013 bucked in an 8' video - 0 views

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    Very comprehensive thanks to the narrator from EUMETSAT training office (plus aesthetically pleasing)
Athanasia Nikolaou

Spray cyanobacteria on the desert to halt its spread - 2 views

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    A wide scale 8 year experiment in China on combating desertification seems to have been successful. Instead of using cyanobacteria blooms in the sea, the tested method proposes to spray them on the boundaries of desert/farmland every few days, so that the carbon they capture stays on the ground. It is useful in fixing the organic material against wind erosion only complementary to planting hardy grasses.

    Very fast result, nevertheless. Could be classified as a geoengineering activity.
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    130 km2 as next step will be quite an area
Athanasia Nikolaou

Aquifer discovered enclosed in Greenland ice sheet - 2 views

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    As the researchers desribe, the aquifer found is defined as a basin filled with aged snow (firn) that was saturated with water trapped within its porous structure.

    More ice cores to study! But in that case the time sequence along the length of the cores - to be extracted- would not be monotonic, as was the case in the dry cores we analysed. That's because there is constant input of surface water percolating through the ice-sheet to reach the depth of the aquifer, and since it flows downward its temperature could affect its partial pressure => its vertical position along the core
Dario Izzo

Extreme weather events study - 2 views

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    Is this correct? The conclusions indicate that contrary to what felt extreme weather events are not increasing?? Where is the trick?
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    don't get fooled, this is the same strategy employed successfully by the tabac industry: installing doubt - all under the cover of science of course and using its methods; remember all these publications showing the overall beneficial effects of smoking, the "un-clear" link to lung cancer etc ... same here
Athanasia Nikolaou

Nature Paper: Rivers and streams release more CO2 than previously believed - 6 views

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    Another underestimated source of CO2, are turbulent waters. "The stronger the turbulences at the water's surface, the more CO2 is released into the atmosphere. The combination of maps and data revealed that, while the CO2 emissions from lakes and reservoirs are lower than assumed, those from rivers and streams are three times as high as previously believed." Alltogether the emitted CO2 equates to roughly one-fifth of the emissions caused by humans. Yet more stuff to model...
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    This could also be a mechanism to counter human CO2 emission ... the more we emit, the less turbulent rivers and stream, the less CO2 is emitted there ... makes sense?
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    I guess there is a natural equilibrium there. Once the climate warms up enough for all rivers and streams to evaporate they will not contribute CO2 anymore - which stops their contribution to global warming. So the problem is also the solution (as always).
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    "The source of inland water CO2 is still not known with certainty and new studies are needed to research the mechanisms controlling CO2 evasion globally." It is another source of CO2 this one, and the turbulence in the rivers is independent of our emissions in CO2 and just facilitates the process of releasing CO2 waters. Dario, if I understood correct you have in mind a finite quantity of CO2 that the atmosphere can accomodate, and to my knowledge this does not happen, so I cannot find a relevant feedback there.

    Johannes, H2O is a powerful greenhouse gas :-)
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    Nasia I think you did not get my point (a joke, really, that Johannes continued) .... by emitting more CO2 we warm up the planet thus drying up rivers and lakes which will, in turn emit less CO2 :) No finite quantity of CO2 in the atmosphere is needed to close this loop ...

    ... as for the H2O it could just go into non turbulent waters rather than staying into the atmosphere ...
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    Really awkward joke explanation: I got the joke of Johannes, but maybe you did not get mine: by warming up the planet to get rid of the rivers and their problems, the water of the rivers will be accomodated in the atmosphere, therefore, the greenhouse gas of water.
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    from my previous post:

    "... as for the H2O it could just go into non turbulent waters rather than staying into the atmosphere ..."
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    I guess the emphasis is on "could"... ;-)
    Also, everybody knows that rain is cold - so more water in the atmosphere makes the climate colder.
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    do you have the nature paper also? looks like very nice, meticulous typically german research lasting over 10 years with painstakingly many researchers from all over the world involved .... and while important the total is still only 20% of human emissions ... so a variation in it does not seem to change the overall picture
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    here is the nature paper :
    http://www.nature.com/nature/journal/v503/n7476/full/nature12760.html

    I appreciate Johannes' and Dario's jokes, since climate is the common ground that all of us can have an opinion, taking honours from experiencing weather. But, the same as if I am trying to make jokes for material science, or A.I. I take a high risk of failing(!) :-S Water is a greenhouse gas, rain rather releases latent heat to the environment in order to be formed, Johannes, nice trolling effort ;-)

    Between this and the next jokes to come, I would stop to take a look here, provided you have 10 minutes: how/where rain forms
    http://www.scribd.com/doc/58033704/Tephigrams-for-Dummies
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    omg
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    Nasia, I thought about your statement carefully - and I cannot agree with you. Water is not a greenhouse gas. It is instead a liquid. Also, I can't believe you keep feeding the troll! :-P
    But on a more topical note: I think it is an over-simplification to call water a greenhouse gas - water is one of the most important mechanisms in the way Earth handles heat input from the sun. The latent heat that you mention actually cools Earth: solar energy that would otherwise heat Earth's surface is ABSORBED as latent heat by water which consequently evaporates - the same water condenses into rain drops at high altitudes and releases this stored heat. In effect the water cycle is a mechanism of heat transport from low altitude to high altitude where the chance of infrared radiation escaping into space is much higher due to the much thinner layer of atmosphere above (including the smaller abundance of greenhouse gasses). Also, as I know you are well aware, the cloud cover that results from water condensation in the troposphere dramatically increases albedo which has a cooling effect on climate. Furthermore the heat capacity of wet air ("humid heat") is much larger than that of dry air - so any advective heat transfer due to air currents is more efficient in wet air - transporting heat from warm areas to a natural heat sink e.g. polar regions.
    Of course there are also climate heating effects of water like the absorption of IR radiation. But I stand by my statement (as defended in the above) that rain cools the atmosphere.
    Oh and also some nice reading material on the complexities related to climate feedback due to sea surface temperature: http://journals.ametsoc.org/doi/abs/10.1175/1520-0442(1993)006%3C2049%3ALSEOTR%3E2.0.CO%3B2
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    I enjoy trolling conversations when there is a gain for both sides at the end :-) .

    I had to check upon some of the facts in order to explain my self properly. The IPCC report states the greenhouse gases here, and water vapour is included:
    http://www.ipcc.ch/publications_and_data/ar4/wg1/en/faq-2-1.html

    Honestly, I read only the abstract of the article you posted, which is a very interesting hypothesis on the mechanism of regulating sea surface temperature, but it is very localized to the tropics (vivid convection, storms) a region of which I have very little expertise, and is difficult to study because it has non-hydrostatic dynamics. The only thing I can comment there is that the authors define constant relative humidity for the bottom layer, supplied by the oceanic surface, which limits the implementation of the concept on other earth regions.

    Also, we may confuse during the conversation the greenhouse gas with the Radiative Forcing of each greenhouse gas: I see your point of the latent heat trapped in the water vapour, and I agree, but the effect of the water is that it traps even as latent heat an amount of LR that would otherwise escape back to space. That is the greenhouse gas identity

    and an image to see the absorption bands in the atmosphere and how important the water is, without vain authority-based arguments that miss the explanation in the end:

    http://www.google.nl/imgres?imgurl=http://www.solarchords.com/uploaded/82/87-33833-450015_44absorbspec.gif&imgrefurl=http://www.solarchords.com/agw-science/4/greenhouse--1-radiation/33784/&h=468&w=458&sz=28&tbnid=x2NtfKh5OPM7lM:&tbnh=98&tbnw=96&zoom=1&usg=__KldteWbV19nVPbbsC4jsOgzCK6E=&docid=cMRZ9f22jbtYPM&sa=X&ei=SwynUq2TMqiS0QXVq4C4Aw&ved=0CDkQ9QEwAw
Athanasia Nikolaou

The tipping elements in the climate system - 2 views

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    Putting together the picture of how climate works. An informative slide that shows which are the climatic subsystems that can undergo(/have undergone in the past) bifurcations (Lenton et al., 2008 PNAS).
Athanasia Nikolaou

Study finds link between the atmospheric rivers and climate - 1 views

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    Atmospheric rivers, short-lived wind tunnels are created in the upper troposphere and carry vast amounts of water. They 'fuel' from the tropical Pacific reservoir and cause heavy precipitation events and even floods to mid-latitude land, as soon as they encounter the Sierra mountains. The new finding is that two inter-hemispheric climatic oscillation modes allow for their creation, as soon as they are found in a certain phase combination.
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    Could we conceivably control these like we're thinking to do with taifuns? :))
    Would be geoengineering at its finest
johannessimon81

Oxygen may have appeared in Earth's atmosphere 700 million years earlier than previousl... - 1 views

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    Indicators found in 3 billion year old rocks
Dario Izzo

Climate scientists told to 'cover up' the fact that the Earth's temperature hasn't rise... - 5 views

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    This is becoming a mess :)
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    I would avoid reading climate science from political journals, for a less selective / dramatic picture :-) . Here is a good start:
    http://www.realclimate.org/

    And an article on why climate understanding should be approached hierarcically, (that is not the way done in the IPCC), a view with insight, 8 years ago: http://www.princeton.edu/aos/people/graduate_students/hill/files/held2005.pdf
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    True, but fundings are allocated to climate modelling 'science' on the basis of political decisions, not solid and boring scientific truisms such as 'all models are wrong'.

    The reason so many people got trained on this area in the past years is that resources were allocated to climate science on the basis of the dramatic picture depicted by some scientists when it was indeed convenient for them to be dramatic.
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    I see your point, and I agree that funding was also promoted through the energy players and their political influence. A coincident parallel interest which is irrelevant to the fact that the question remains vital. How do we affect climate and how does it respond. Huge complex system to analyse which responds in various time scales which could obscure the trend.

    What if we made a conceptual parallelism with the L Ácquila case : Is the scientific method guilty or the interpretation of uncertainty in terms of societal mobilization? Should we leave the humanitarian aspect outside any scientific activity?
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    I do not think there is anyone arguing that the question is not interesting and complex.

    The debate, instead, addresses the predictive value of the models produced so far. Are they good enough to be used outside of the scientific process aimed at improving them? Or should one wait for "the scientific method" to bring forth substantial improvements to the current understanding and only then start using its results? One can take both stand points, but some recent developments will bring many towards the second approach.
Dario Izzo

IPCC models getting mushy | Financial Post - 2 views

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    why am I not surprised .....
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    http://www.academia.edu/4210419/Can_climate_models_explain_the_recent_stagnation_in_global_warming
    A view of well-respected scientists on how to proceed from here, that was rejected from Nature. In any case, a long way to go...
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    unfortunately it's too early to cheer and burn more coal ...

    there is also a nice podcast associated to this paper from nature

    Recent global-warming hiatus tied to equatorial Pacific surface cooling

    Yu Kosaka & Shang-Ping Xie
    Nature 501, 403-407 (19 September 2013) doi:10.1038/nature12534
    Received 18 June 2013 Accepted 08 August 2013 Published online 28 August 2013

    Despite the continued increase in atmospheric greenhouse gas concentrations, the annual-mean global temperature has not risen in the twenty-first century1, 2, challenging the prevailing view that anthropogenic forcing causes climate warming. Various mechanisms have been proposed for this hiatus in global warming3, 4, 5, 6, but their relative importance has not been quantified, hampering observational estimates of climate sensitivity. Here we show that accounting for recent cooling in the eastern equatorial Pacific reconciles climate simulations and observations. We present a novel method of uncovering mechanisms for global temperature change by prescribing, in addition to radiative forcing, the observed history of sea surface temperature over the central to eastern tropical Pacific in a climate model. Although the surface temperature prescription is limited to only 8.2% of the global surface, our model reproduces the annual-mean global temperature remarkably well with correlation coefficient r = 0.97 for 1970-2012 (which includes the current hiatus and a period of accelerated global warming). Moreover, our simulation captures major seasonal and regional characteristics of the hiatus, including the intensified Walker circulation, the winter cooling in northwestern North America and the prolonged drought in the southern USA. Our results show that the current hiatus is part of natural climate variability, tied specifically to a La-Niña-like decadal cooling. Although similar decadal hiatus events may occur in the future, the multi-decadal warming trend is very likely to continue with greenhouse gas
Dario Izzo

Climatologists are no Einsteins, says his successor | NJ.com - 2 views

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    I know at least of a few people who share this point of view :)
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    I think it is worth noting that Dyson's is not saying that climate change is an illusion - it is evident that a lot of CO2 is emitted into the atmosphere and hence something will change. His point is that we just don't know what will change and by how much and that (much) more experimental data is necessary to make predictive models.
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    On missing experimental work: just read in the news that condensation in cirrus clouds has been studied recently and that the models where incorrect as to what the significance of organic substances and soot is in cirrus cloud formation. http://www.sciencemag.org/content/early/2013/05/08/science.1234145
Isabelle Dicaire

Statistical physics offers a new way to look at climate - 2 views

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    New Earth climate model based on statistical physics and available on the App Store !
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    not overly intuitive ...
Dario Izzo

Global Climate Models Powered by Intel® Xeon Phi™ Coprocessors - 1 views

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    NASA has it ... I WANT IT TOO!!!!
    240 threads on 60 cores ...

    Imagine the possibilities of this new toy!!

    Francesco also has it in his new "kill the seals" job
LeopoldS

Management of trade-offs in geoengineering through optimal choice of non-uniform radiat... - 1 views

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    Nice modelling research on geo engineering options ...
Dario Izzo

http://thegwpf.org/images/stories/gwpf-reports/hughes-evidence.pdf - 2 views

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    The Global Warming Policy Foundations has warned policy makers that wind energy is an extraordinarily expensive and inefficient way of reducing CO2 emissions.
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