Allen and Ingram can be made to work. Taking the slow increase of precipitation with temperature as a given, the more rapid increase of boundary layer humidity implies that the rate of transport of moisture from the boundary layer to higher levels where it rains out must go down. One way to do this is to decrease the strength of large scale circulations like the walker and Hadley circulations. If this argument seems obscure, heres an analogy that may prove helpful. Suppose you live on a tropical island where water must be brought in buckets to your hut by the local authorities. The size of the buckets (which are always full) stands in for the boundary layer water vapor content. You need the water because you raise pigs, which are very temperature sensitive; to keep them comfortable you need to throw a certain amount of water over them each day.
Anthropogenic, global Warming - fact or hoax?
Observations tend to support the expected increase (e.g. Wentz and Schabel, nature 403, january 2000. Some of the observational references given by vecchi. In support of the increase actually deal more with the extratropics than the tropics, but the general principle is not seriously in question.) One might then expect that there would be a precipitation increase in proportion to the increase in water vapor content. However, it has been known since the earliest general circulation simulations by manabe that as the earth warms in response to increasing CO2, the precipitation increases much more slowly than Clausius-Clapeyron would suggest — typically only 2-3 per degree of warming. Because latent afrikaans heat release in the course of precipitation must be balanced in the global mean by infrared radiative cooling of the troposphere (over time essay scales at which the atmosphere is approximately in equilibrium it is sometimes argued that radiative constraints limit the rate. This argument is stated, for example,. And repeated in Vecchi. The argument isnt actually as firm a constraint as generally believed, since the infrared radiative cooling of the atmosphere is affected by the temperature difference between air and the underlying surface, which can adjust to accommodate any amount of evaporation Nature wants to dump into. This is why single-column radiative convective models can show stronger increases of precipitation with temperature, even approaching the Clausius-Clapeyron limit. However, the relatively weak increase in precipitation with temperature seen in general circulation models is robust across models, suggesting that with suitable additional conditions the argument given.
Most press reports summarized this result as a "weakening of the Trade winds" in response to global warming. As a description, thats not too bad, given umum that the indicated trend in the walker circulation does indeed lead to a weakening of the Trades over most of the pacific. However, the Trade winds are primarily caused by the hadley circulation, and are only modulated by the walker circulation, so it is more precise to think of this result as indicating a change in strength of the walker circulation. Circulations and the hydrological cycle in a warming world. One of the things that makes the findings of Vecchi. Especially interesting is that they are consistent with some rather robust theoretical arguments linking the strength of circulations to certain aspects of changes in precipitation and water vapor. These arguments are explained in more detail in Held and Soden 2006 (preprint available here ). The argument begins by noting that the. Clausius-Clapeyron equation, predicts a strong increase of boundary layer water vapor content with temperature (about 7 per degree of warming the increase of low level water vapor with temperature is not controversial, since oceanic boundary layers are in contact with their moisture source and stay.
Instrumentation for accurately measuring winds only came along later, to say nothing of instrumentation for monitoring convection patterns or the subtle circulation aloft. Surface pressure provides a good proxy for the walker circulation because, near the Equator, winds tend to flow from regions of high pressure to regions of low pressure, under the acccelerating action of pressure gradient forces. In the walker circulation, the low pressure is in the west Pacific and the high pressure is in the east Pacific. This gradient strengthens the easterly Trade winds to the east of the rising branch (above the low pressure cell) and counters the easterly Trades on the west side of the low pressure cell, weakening them or even turning them into westerlies. (see the walker cell sketch in, part I ). The following figure shows maps of the observed and modeled pressure changes between 18The observations (upper left panel) show an increase of pressure in the western Pacific and a decrease of pressure in the eastern Pacific, indicating a weakening of the east-west pressure gradient associated. The model plan simulations (upper right panel) driven by all known climate forcings over the period in question show a very similar pattern of weakening. The bottom two panels demonstrate that this weakening is due entirely to the anthropogenic forcings — greenhouse gas increases offset by sulfate aerosol effects. The simulations shown are the mean of an ensemble of five simulations of the period starting with slightly different initial conditions.
It also provides the background state against which El niño events take place, and so changes in the walker circulation should form an intrinsic part of thinking about how global warming will affect El niño. In a paper that recently appeared. Nature, vecchi, soden, wittenberg, held, leetmaa and Harrison present intriguing new results which suggest that there has already been a weakening of the walker circulation in the past century, and that the observed changes are consistent with those expected as a response to increases. The discussion in Vecchi. Also raises some very interesting issues regarding the way the hydrological cycle might change in a warming world. The main result of the paper. Compared the observed trend in the walker circulation between 18 to that yielded by simulations from the gfdl cm2 general circulation model, run with and without anthropogenic forcing. The comparison was done on the basis of surface pressure, because the humble barometer is a simple instrument which, with low technology, can nonetheless yield very accurate results; hence there are good long term instrumental records from the logs of intrepid tropical mariners.
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I challenge anyone to conclusively demonstrate that such catastrophes as listed above may await us if we try to reduce fossil fuel usage. Now, in terms of conservation and a global switch over to alternative fuels, the people who oppose doing this for climate change mitigation are forgetting something rather important. Fossil fuels are a non-renewable resource, and as such we have to make this global economic transformation regardless, be it now or a bit later. Many bright minds inside the industry think we are already at peak oil. So even if it turned out that climate mitigation actions were unnecessary, we would nevertheless be in a better place as a global society by making the coming switch sooner rather than later. Seems like a win-win situation. Action on Global Warming is suicide was first published here, where you can still find the original comment thread.
This updated version is also posted on the. Grist website, where additional comments can be found, though the author, coby beck, does not monitor or respond there. By ray pierrehumbert and Rasmus Benestad. Second article of our vegetable 3-part series on atmospheric circulation and global warming. In, part I we outlined some general features of the tropical circulation, and discussed ways in which increases in anthropogenic greenhouse gases might affect El niño. Now we take up the question of how global warming might affect the quasi-steady east-west overturning circulation known as the walker Circulation. The walker circulation affects convection and precipitation patterns, the easterly Trade winds, oceanic upwelling and ocean biological productivity; hence, changes in this circulation can have far-reaching consequences.
Leach, jianfa bai, amgad Saleh, Alan. Fay, jesse nippert, patrick. Smith evidence for climatic niche and biome shifts between native and novel ranges in plant species introduced to australia rachael. Beaumont, lesley hughes, michelle. Leishman High Arctic plant community resists 15 years of experimental warming James Hudson, Greg Henry complex responses to climate drivers in onset of spring flowering across a semi-arid elevation gradient Theresa Crimmins, michael Crimmins,. This is just one of dozens of responses to common climate change denial arguments, which can all be found.
How to talk to a climate Sceptic. Objection: The kind of drastic actions required to mitigate Global Warming will risk the destruction of the global economy and the deaths of potentially billions of people. Answer: Is this supposed to mean that the theory of anthropogenic global warming must be wrong? . you can not come to a rational decision about the reality of a danger by only considering how hard it might be to avoid. First things first, understand that the problem is real and present. Once you acknowledge the necessity of addressing the problem, taking action suddenly become less daunting. There is no point in discussing the best solutions or the cost of those solutions with someone who does not yet acknowledge the problem. But even if mitigating Global Warming would be harmful, given that famine, droughts, disease, loss of major coastal cities and a tremendous mass extinction event are on the table as possible consequences of doing nothing, it may well be we are faced with a choice.
Global Warming, skeptic Organizations (2013) Union
Global patterns in plant height, angela. Warton, laura warman, nathan. Zanne, andy pitman, Frank. Winter warming events damage sub-Arctic vegetation: consistent evidence from an experimental manipulation and a natural student event Stef. Bjerke, hans Tømmervik, terry. Phoenix Volume 98 (2010) Response best of the prairieforest border to climate change: impacts of increasing drought may be mitigated by increasing CO2 Peter. Wyckoff, rachel Bowers Variation in gene expression of Andropogon gerardii in response to altered environmental conditions associated with climate change Steven. Travers, Zhongwen Tang, doina caragea, karen.
Regional tree line dynamics in response to global change in the pyrenees. Enric Batllori, emilia gutiérrez, volume writing 97 (2009 post-Little Ice Age tree line rise and climate warming in the Swedish Scandes: a landscape ecological perspective. Leif Kullman, lisa Öberg, decomposition in tropical forests: a pan-tropical study of the effects of litter type, litter placement and mesofaunal exclusion across a precipitation gradient. Carol Adair, Francis. Castanho, jerome Chave, erika deinert, jörg. Gilbert, josé Antonio gonzález-iturbe, sarayudh Bunyavejchewin,. Ricardo Grau, kyle. Harms, Ankila hiremath, silvia iriarte-vivar, Eric Manzane, alexandre. De Oliveira, lourens poorter, jean-Baptiste ramanamanjato, carl Salk, amanda varela, george.
cold biomes. Rien Aerts, standard Paper, volume 95 (2007 tree line population monitoring. Pinus sylvestris in the Swedish Scandes, 19732005: implications for tree line theory and climate change ecology. Leif Kullman, volume 96 (2008 using rainout shelters to evaluate climate change effects on the demography. Cryptantha flava, richard.
The journal is the essay oldest ecological journal in the world, published continuously since 1913 by the British Ecological Society. Journal of Ecology is truly one of most important ecological journals available, having an Impact Factor in 2010.69 and being ranked 12th of 124 ecological journals. Journal of Ecology was recognized in 2009 by the Special Libraries Association as being one of the top 100 most influential journals in biology and Medicine in the last 100 years. We invite you to read and share with colleagues the papers in this Virtual Issue, visit the journal website, consider taking out a subscription if you don't have one already, and submit your best work to the journal for potential publication. Special feature essay review, the changing global carbon cycle: linking plantsoil carbon dynamics to global consequences. Stuart Chapin iii, jack McFarland,. David McGuire, eugenie.
Persuasive essay : outline, format, structure
Home virtual Issues virtual Issue global Warming, edited by mike hutchings, david Gibson, richard Bardgett and Mark rees. August 2010, the editors of, journal of Ecology are pleased to present this Virtual Issue on report Global Warming to coincide with the 95th Annual meeting of the Ecological Society of America in Pittsburgh, pennsylvania, in 2010, which places global warming at center stage. This Virtual Issue is a selection of 14 papers published. Journal of Ecology over the last 4 years on the topic of climate change. The papers not only demonstrate the breadth of work published in the journal on this topic, but also show that effects of climate change are far ranging. Topics range from studies on effects of natural winter warming events on sub-Arctic vegetation, to studies that explore the effects of climate change on tree lines, decomposition processes, and on individual plant species and their gene expression. Important concepts are also considered, such as the integration of plantsoil interactions into global carbon cycle models, which lie at the heart of understanding the global consequences of warming for the earth system. It is clear that global warming will continue to exert influence across all levels of ecological organization, and many of the most compelling and important studies in this area are being published. The papers included in this Virtual Issue reflect the international scope and range.