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Originally posted by pasiphae
the whole reason i even became a member in the first place was due to this forum... it's not the same as it was.edit on 15-6-2012 by pasiphae because: (no reason given)
Originally posted by Moshpet
...
There is a vast difference in what a human exudes in a breathe versus what any burned fossil creates when burned. Quit trying to confuse the issue. Trying to say the pollution is not happening just because there is CO2 in the gasses, along with other carbon particulate matter and waste; is just a way of lying to yourself and others.
...
Originally posted by smirkley
Yes. Is there no way back.
PRESS RELEASE
Date Released: Thursday, June 5, 2003
Source: Goddard Space Flight Center
A NASA-Department of Energy jointly funded study concludes the Earth has been greening over the past 20 years. As climate changed, plants found it easier to grow.
The globally comprehensive, multi-discipline study appears in this week's Science magazine. The article states climate changes have provided extra doses of water, heat and sunlight in areas where one or more of those ingredients may have been lacking. Plants flourished in places where climatic conditions previously limited growth.
"Our study proposes climatic changes as the leading cause for the increases in plant growth over the last two decades, with lesser contribution from carbon dioxide fertilization and forest re-growth," said Ramakrishna Nemani, the study's lead author from the University of Montana, Missoula, Mont.
...
On-line Publication Documentation System for Stockholm University
Full DescriptionUpdate record
Publication type: Article in journal (Reviewed scientific)
Author: Grudd, H (Department of Physical Geography and Quaternary Geology)
Title: Torneträsk tree-ring width and density ad 500–2004: a test of climatic sensitivity and a new 1500-year reconstruction of north Fennoscandian summers
In: Climate Dynamics
Publisher: Springer, Berlin / Heidelberg
Volume: 31
Pages: 843-857
Year: 2008
Available: 2009-01-30
ISSN: 1432-0894
Department: Department of Physical Geography and Quaternary Geology
Language: English [en]
Subject: Physical geography, Climatology
Abstract: This paper presents updated tree-ring width (TRW) and maximum density (MXD) from Torneträsk in northern Sweden, now covering the period ad 500–2004. By including data from relatively young trees for the most recent period, a previously noted decline in recent MXD is eliminated. Non-climatological growth trends in the data are removed using Regional Curve Standardization (RCS), thus producing TRW and MXD chronologies with preserved low-frequency variability. The chronologies are calibrated using local and regional instrumental climate records. A bootstrapped response function analysis using regional climate data shows that tree growth is forced by April–August temperatures and that the regression weights for MXD are much stronger than for TRW. The robustness of the reconstruction equation is verified by independent temperature data and shows that 63–64% of the instrumental inter-annual variation is captured by the tree-ring data. This is a significant improvement compared to previously published reconstructions based on tree-ring data from Torneträsk. A divergence phenomenon around ad 1800, expressed as an increase in TRW that is not paralleled by temperature and MXD, is most likely an effect of major changes in the density of the pine population at this northern tree-line site. The bias introduced by this TRW phenomenon is assessed by producing a summer temperature reconstruction based on MXD exclusively. The new data show generally higher temperature estimates than previous reconstructions based on Torneträsk tree-ring data. The late-twentieth century, however, is not exceptionally warm in the new record: On decadal-to-centennial timescales, periods around ad 750, 1000, 1400, and 1750 were equally warm, or warmer. The 200-year long warm period centered on ad 1000 was significantly warmer than the late-twentieth century (p < 0.05) and is supported by other local and regional paleoclimate data. The new tree-ring evidence from Torneträsk suggests that this “Medieval Warm Period” in northern Fennoscandia was much warmer than previously recognized.
Glacial geological evidence for the medieval warm period
Journal Climatic Change
Publisher Springer Netherlands
ISSN 0165-0009 (Print) 1573-1480 (Online)
Issue Volume 26, Numbers 2-3 / March, 1994
DOI 10.1007/BF01092411
Pages 143-169
Subject Collection Earth and Environmental Science
SpringerLink Date Monday, February 07, 2005
Jean M. Grove1 and Roy Switsur2
(1) Girton College, Cambridge, U.K.
(2) Wolfson College, Cambridge, U.K.
Received: 22 September 1992 Revised: 12 October 1993
Abstract It is hypothesised that the Medieval Warm Period was preceded and followed by periods of moraine deposition associated with glacier expansion. Improvements in the methodology of radiocarbon calibration make it possible to convert radiocarbon ages to calendar dates with greater precision than was previously possible. Dating of organic material closely associated with moraines in many montane regions has reached the point where it is possible to survey available information concerning the timing of the medieval warm period. The results suggest that it was a global event occurring between about 900 and 1250 A.D., possibly interrupted by a minor readvance of ice between about 1050 and 1150 A.D.
P. D. Tyson, W. Karlén, K. Holmgren and G. A. Heiss (in press) The Little Ice Age and Medieval Warming in South Africa. South African Journal of Science.
--------------------------------------------------------------------------------
The Little Ice Age and Medieval Warming in South Africa
P. D. Tyson1, W. Karlén2, K. Holmgren2 and G. A. Heiss3.
1Climatology Research Group, University of the Witwatersrand
2Department of Physical Geography, Stockholm University
3Geomar, Wischhofstr. 1-3, 24148 Kiel, Germany; present address: German Advisory Council on Global Change (WBGU), P.O. Box 120161, 27515 Bremerhaven, Germany, E-mail: [email protected]
Abstract
The Little Ice Age, from around 1300 to 1800, and medieval warming, from before 1000 to around 1300 in South Africa, are shown to be distinctive features of the regional climate of the last millennium. The proxy climate record has been constituted from oxygen and carbon isotope and colour density data obtained from a well-dated stalagmite derived from Cold Air Cave in the Makapansgat Valley.
The climate of the interior of South Africa was around 1oC cooler in the Little Ice Age and may have been over 3°C higher than at present during the extremes of the medieval warm period. It was variable throughout the millennium, but considerably more so during the warming of the eleventh to thirteenth centuries. Extreme events in the record show distinct teleconnections with similar events in other parts of the world, in both the northern and southern hemispheres. The lowest temperature events recorded during the Little Ice Age in South Africa are shown to be coeval with the Maunder and Sporer Minima in solar irradiance. The medieval warming is shown to have been coincided with the cosmogenic 10Be and 14C isotopic maxima recorded in tree rings elsewhere in the world during the Medieval Maximum in solar radiation.
Originally published in Science Express on 19 June 2008
Science 1 August 2008:
Vol. 321. no. 5889, pp. 680 - 684
DOI: 10.1126/science.1157707
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Reports
High-Resolution Greenland Ice Core Data Show Abrupt Climate Change Happens in Few Years
Jørgen Peder Steffensen,1* Katrine K. Andersen,1 Matthias Bigler,1,2 Henrik B. Clausen,1 Dorthe Dahl-Jensen,1 Hubertus Fischer,2,3 Kumiko Goto-Azuma,4 Margareta Hansson,5 Sigfús J. Johnsen,1 Jean Jouzel,6 Valérie Masson-Delmotte,6 Trevor Popp,7 Sune O. Rasmussen,1 Regine Röthlisberger,2,8 Urs Ruth,3 Bernhard Stauffer,2 Marie-Louise Siggaard-Andersen,1 Árn E. Sveinbjörnsdóttir,9 Anders Svensson,1 James W. C. White7
The last two abrupt warmings at the onset of our present warm interglacial period, interrupted by the Younger Dryas cooling event, were investigated at high temporal resolution from the North Greenland Ice Core Project ice core. The deuterium excess, a proxy of Greenland precipitation moisture source, switched mode within 1 to 3 years over these transitions and initiated a more gradual change (over 50 years) of the Greenland air temperature, as recorded by stable water isotopes. The onsets of both abrupt Greenland warmings were slightly preceded by decreasing Greenland dust deposition, reflecting the wetting of Asian deserts. A northern shift of the Intertropical Convergence Zone could be the trigger of these abrupt shifts of Northern Hemisphere atmospheric circulation, resulting in changes of 2 to 4 kelvin in Greenland moisture source temperature from one year to the next.
Evidence for the existence of the medieval warm period in China
Journal Climatic Change
Publisher Springer Netherlands
ISSN 0165-0009 (Print) 1573-1480 (Online)
Issue Volume 26, Numbers 2-3 / March, 1994
DOI 10.1007/BF01092419
Pages 289-297
Subject Collection Earth and Environmental Science
SpringerLink Date Monday, February 07, 2005
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Evidence for the existence of the medieval warm period in China
De'Er Zhang1
(1) Chinese Academy of Meteorological Sciences, Baishiqiaolu No. 46, 100081 Beijing, China
Abstract The collected documentary records of the cultivation of citrus trees andBoehmeria nivea (a perennial herb) have been used to produce distribution maps of these plants for the eighth, twelfth and thirteenth centuries A.D. The northern boundary of citrus andBoehmeria nivea cultivation in the thirteenth century lay to the north of the modern distribution. During the last 1000 years, the thirteenth-century boundary was the northernmost. This indicates that this was the warmest time in that period. On the basis of knowledge of the climatic conditions required for planting these species, it can be estimated that the annual mean temperature in south Henan Province in the thirteenth century was 0.9–1.0°C higher than at present. A new set of data for the latest snowfall date in Hangzhou from A.D. 1131 to 1264 indicates that this cannot be considered a cold period, as previously believed.
Title:
Late Holocene Environmental and Hydrologic Conditions in Northwestern Florida Derived from Seasonally Resolved Profiles of δ18O and Sr/Ca of Fossil Bivalves.
Authors:
Elliot, M.; de Menocal, P. B.; Linsley, B. K.; Howe, S. S.; Guilderson, T.; Quitmyer, I. R.
Affiliation:
AA(Edinburgh University, Dept. Geology and Geophysics, West Mains Road, Edinburgh, EH9 3JW United Kingdom ; [email protected]), AB(Lamont Doherty Earth Observatory, Route 9W, Palisades, NY 10964 ; [email protected]), AC(University at Albany, 1400 Washington Ave, Albany, NY 12222 ; [email protected]), AD(Laurence Livermore National Laboratory, 7000 East Ave, Livermore, CA 94550 ; [email protected]), AE(Laurence Livermore National Laboratory, 7000 East Ave, Livermore, CA 94550 ; ), AF(Florida Museum of Natural History, Dickinson Hall, Gainesville, FL 32611 ; )
Publication:
American Geophysical Union, Fall Meeting 2002, abstract #PP72A-0429
Publication Date:
12/2002
Origin:
AGU
AGU Keywords:
3344 Paleoclimatology, 4215 Climate and interannual variability (3309), 4227 Diurnal, seasonal, and annual cycles, 4870 Stable isotopes, 4875 Trace elements
Bibliographic Code:
2002AGUFMPP72A0429E
Abstract
We reconstruct environmental conditions of coastal Northwestern Florida from combined measurements of δ18O and Sr/Ca of fossil marine bivalves deposited in an archeological site during the late Holocene period. We first investigated the environmental controls of seasonally resolved records of δ18O and Sr/Ca of modern Mercenaria mercenaria and Mercenaria campesiensis collected live from five coastal sites along the east coast of North America. Seasonal profiles were obtained by sub-sampling the incremental growth layers of aragonite and were compared with in situ historical records of temperature and salinity. We show that these bivalves precipitate their shell in isotopic equilibrium with the water in which they grew and that the δ18O records are not affected by variations in growth rate. Winter growth appears to be interrupted or strongly reduced below water temperatures ranging from 7 to 18° C, depending on latitude. The annual average δ18O decreases with latitude, reflecting both the parallel trend of freshwater δ18O with latitude over the North American continent and the reduced winter growth rate. The Sr/Ca records of the 5 modern bivalves also exhibit seasonal variations can be correlated to water temperature. However, contrary to corals, the Sr/Ca ratio is considerably lower than the average sea water Sr/Ca composition and is positively correlated to the water temperature. We dated and measured the δ18O and Sr/Ca of 30 fossil M. campesiensis from an archeological site close to Cedar Key, in the Gulf of Mexico. Accelerator Mass Spectrometry 14C dates obtained for each shell show ages which cluster between 1100 to 1400 and 2300 to 2600 14C years BP corresponding approximately to two historical warm periods known as the Medieval Warm Period (~ 1300-900AD) and the Roman Warm Period (~ 250AD-200BC). The average annual and summer Sr/Ca of 4 fossil shells are higher than that of modern bivalves from the same location suggesting that annual coastal water temperatures were 3 to 4° C warmer than today. The bulk δ18O values show a marked trend towards more positive values. 24 fossil shells have bulk δ18O values 0.2permil to 0.7permil more positive than modern bivalves from the same location. These results suggest that the coastal waters off northwest Florida were warmer and less saline compared to today and attest of considerable differences of the regional climate and hydrological balance during the Medieval Warm Period and Roman Warm Period.
Climate Change: Driven by the Ocean not Human Activity
by
William M. Gray
Professor Emeritus, Dept of Atmospheric Science,
Colorado State University
Prepared for the 2nd Annual Heartland Institute sponsored conference on Climate Change. New York City, March 8-10, 2009
Paper also available at tropical.atmos.colostate.edu... (under News)
Abstract
This paper discusses how the variation in the global ocean’s Meridional Overturning Circulation (MOC) resulting from changes in the Atlantic Thermohaline Circulation (THC) and deep water Surrounding Antarctica Subsidence (SAS) can be the primary cause of climate change. (MOC = THC + SAS) is the likely cause of most of the global warming that has been observed since the start of the industrial revolution (~1850) and for the more recent global warming that has occurred since the mid-1970s. Changes of the MOC since 1995 are hypothesized to have lead to the cessation of global warming since 1998 and to the beginning of a weak global cooling that has occurred since 2001. This weak cooling is projected to go on for the next couple of decades.
Recent GCM global warming scenarios assume that a slightly stronger hydrologic cycle (due to the increase in CO2) will cause additional upper-level tropospheric water vapor and cloudiness. Such vapor-cloudiness increases are assumed to allow the small initial warming due to increased CO2 to be unrealistically multiplied 2-4 or more times. This is where most of the global warming from the GCMs comes from – not the warming resulting from the CO2 increase by itself but the large extra warming due to the assumed increase of upper tropospheric water vapor and cloudiness. As CO2 increases, it does not follow that the net global upper-level water vapor and cloudiness will increase significantly.
Observations of upper tropospheric water vapor over the last 3-4 decades from the National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis data and the International Satellite Cloud Climatology Project (ISCCP) data show that upper tropospheric water vapor appears to undergo a small decrease while Outgoing Longwave Radiation (OLR) undergoes a small increase. This is opposite to what has been programmed into the GCMs. The predicted global warming due to a doubling of CO2 has been erroneously exaggerated by the GCMs due to this water vapor feedback.
CO2 increases without positive water vapor feedback could only have been responsible for about 0.1-0.2oC of the 0.6-0.7oC global mean surface temperature warming that has been observed since the early 20th century. Assuming a doubling of CO2 by the late 21st century (assuming no positive water vapor feedback), we should likely expect to see no more than about 0.3-0.5oC global surface warming and certainly not the 2-5oC warming that has been projected by the GCMs.
Global warming is not so hot:
1003 was worse, researchers find
By William J. Cromie
Gazette Staff
The heat and droughts of 2001 and 2002, and the unending winter of 2002-2003 in the Northeast have people wondering what on Earth is happening to the weather. Is there anything natural about such variability?
To answer that question, researchers at the Harvard-Smithsonian Center for Astrophysics (CfA) - right in the heart of New England's bad weather - took a look at how things have changed in the past 1,000 years. They looked at studies of changes in glaciers, corals, stalagmites, and fossils. They checked investigations of cores drilled out of ice caps and sediments lying on the bottom of lakes, rivers, and seas. They examined research on pollen, tree rings, tree lines, and junk left over from old cultures and colonies. Their conclusion: We are not living either in the warmest years of the past millennium nor in a time with the most extreme weather.
This review of changes in nature and culture during the past 1,000 years was published in the April 11 issue of the Journal of Energy and Environment. It puts subjective observations of climate change on a much firmer objective foundation. For example, tree-ring data show that temperatures were warmer than now in many far northern regions from 950 to 1100 A.D.
From 800 to 1300 A.D., the Medieval Warm Period, many parts of the world were warmer than they have been in recent decades. But temperatures now (including last winter) are generally much milder than they were from 1300 to 1900, the Little Ice Age.
To come to this coclusion, CfA researchers, along with colleagues from the Center for the Study of Carbon Dioxide and Global Change in Tempe, Ariz., and the Center for Climatic Research at the University of Delaware, reviewed more than 200 studies of climate done over the past 10 years. "Many research advances in reconstructing ancient climate have occurred over the past two decades, so we felt it was time to pull together a large sample of them and look for patterns of variability and change," says Willie Soon of CfA. "Clear patterns did emerge showing that regions worldwide experienced higher temperatures from 800 to 1300 and lower temperatures from 1300 to 1900 than we have felt during our lifetimes."
There is not even an attempt to model such complex climate details, as GCMsare too coarse for such purposes. When K. Hasselmann (a leading greenhouse protagonist)was asked why GCMs do not allow for the stratosphere’s warming by the suns ultravioletradation and its impact on the circulation in the troposphere, he answered: “This aspect is too complex to incorporate it into models”[8]. Since there are other solar-terrestrial relationships which are “too complex” such as, for example, the dynamics of cloud coverage modulated by the solar wind, it is no wonder that the predictions based on GCMs do not conform to climate reality.
Copyright © 2005 Elsevier B.V. All rights reserved.
Asian monsoon oscillations in the northeastern Qinghai–Tibet Plateau since the late glacial as interpreted from visible reflectance of Qinghai Lake sediments
Junfeng Jia, , , Ji Shenb, 1, , William Balsamc, 2, , Jun Chena, 3, , Lianwen Liua, 4, and Xingqi Liub, 5,
aState Key Laboratory of Mineral Deposit Research, Institute of Surficial Geochemistry, Department of Earth Sciences, Nanjing University, Nanjing 210093, China
bKey Laboratory of Lake Sedimentation and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
cDepartment of Geology, University of Texas at Arlington, Arlington, TX 76019, USA
Received 28 July 2004; revised 28 January 2005; accepted 15 February 2005. Editor: E. Boyle. Available online 1 April 2005.
Abstract
Qinghai Lake is a large saline lake on the Qinghai–Tibetan Plateau of central Asia that is effected by both the Indian and Asian monsoons. We used reflectance spectroscopy to characterize the sediments in a 795-cm long core taken from the southeastern part of the lake. Sediment redness, which is related to iron oxide content, seems to monitor paleoclimatic changes in the core. Iron oxides appear to be eroded from nearby red beds or loess deposits and are transported by fluvial means into the lake. Thus, redness increases at times of increased precipitation, that is, as monsoon strength increases. Our redness monsoon proxy shows climate changes on several times scales. On a millennial scale, it records humid conditions during the Early and Mid-Holocene. From about 4200 to 2300 yr BP, low redness values suggest a two-millennial long dry period, which in the Late Holocene is followed by a more humid period. On a centennial scale, the redness proxy records not only the Little Ice Age, but also the Medieval Warm Period, the Dark Ages Cool Period and the Roman Warm Period. Time series analysis of the redness record indicates a 200 yr frequency, which corresponds to the de Vries solar cycle suggesting that, in addition to insolation changes resulting from orbital variations, solar forcing also results from cyclic changes in the suns luminosity.
Keywords: Asian monsoon; diffuse reflectance spectrophotometry; Qinghai Lake; sediment redness; iron oxides; solar forcing
doi:10.1016/j.palaeo.2005.07.012
Copyright © 2005 Elsevier B.V. All rights reserved.
Temperature responses to quasi-100-yr solar variability during the past 6000 years based on δ18O of peat cellulose in Hongyuan, eastern Qinghai–Tibet plateau, China
Hai Xua, b, , , , Yetang Hongb, Qinghua Linb, Yongxuan Zhub, Bing Hongb and Hongbo Jiangb
aState Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, 10 Fenghui South Road, High-tech Zone, Xi'an, Shaanxi Province, PO Box 710075, China
bState Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550002, China
Received 28 October 2004; revised 17 July 2005; accepted 19 July 2005. Available online 22 August 2005.
Abstract
During the past 6000 years, the temperature variation trend inferred from δ18O of peat cellulose in a peat core from Hongyuan (eastern Qinghai–Tibet plateau, southwestern China) is similar to the atmospheric 14C concentration trend and the modeled solar output trend. The general trend of Hongyuan δ18O during the past millennium also coincides well with the atmospheric 14C concentration trend, the 10Be concentration trend in an ice core from the South Pole, the reconstructed total solar irradiance trend, as well as the modeled solar output trend. In addition, temperature events also correspond well to solar perturbations during the past 6000 years. Therefore, the driving force of Holocene temperature variations should be properly ascribed to solar activity. The spectrum analysis further illustrates that quasi-100-yr fluctuation of solar activity was probably responsible for temperature variations in northeast Qinghai–Tibet plateau during the past 6000 years.
Keywords: Peat; Oxygen isotopic composition; Temperature; Solar activity; Qinghai–Tibet plateau; China
Originally posted by ElectricUniverse
About the claims how warming "is bad for plants and trees"...
Originally posted by ElectricUniverse
I could keep posting FACT after FACT that shows the current Climate Change is neither the warmest, nor the most extreme, or faster "that has ever happened on Earth"...
Originally posted by AndyMayhew
So? More straw men.
That proves humans are not affecting the climate today in a manner which may be detrimental to us today, how?
Originally posted by AndyMayhew
...
It's a straw man. The fact that an increase in CO2 is not detrimental to plant life is NOT an argument that human activity does not affect climate.
Originally posted by AndyMayhew
...
No-one here is refuting that increased levels of CO2 may be good for plants (although there are caveats to that) or that warming has occurred in the past.
...
Carbon Dioxide (CO2) contributes to plant growth as part of the miracle of nature known as photosynthesis. This enables plants to combine Carbon Dioxide and water with the aid of light energy to form sugar. Some of these sugars are converted into complex compounds that increase dry solid plant substances for continued growth to final maturity. However, when the supply of carbon dioxide is cut off, or reduced, the complex plant cell structure cannot utilize the sun's energy fully and growth or development is curtailed.
CARBON DIOXIDE (CO2)
IMPROVES PLANT GROWTH AND QUALITY
Research has shown that in most cases rate of plant growth under otherwise identical growing conditions is directly related to carbon dioxide concentration.
The amount of carbon dioxide a plant requires to grow may vary from plant to plant, but tests show that most plants will stop growing when the CO2 level decreases below 150 ppm. Even at 220 ppm, a slow-down in plant growth is significantly noticeable.
Colorado State University conducted tests with carnations and other flowers in controlled CO2 atmospheres ranging from 200 to 550 ppm. The higher CO2 concentrations significantly increased the rate of formation of dry plant matter, total flower yield and market value.
SAMPLE RESULTS FROM CO2 ENRICHMENT STUDIES
BIBB LETTUCE
By adding CO2 to the atmosphere around the plant, a 40% crop increase was achieved. Whereas previous crops averaged 22 heads per basket, lettuce grown in the increased CO2 atmosphere (550 ppm) averaged 16 heads of better quality per basket.
CARNATIONS
CO2 levels to 550 ppm produced an obvious increase in yield (over 30%), but the greatest benefits were earlier flowering (up to 2 weeks) with an increased percentage of dry matter.
ROSES
The addition of controlled carbon dioxide provided a remarkable improvement in blossom quality, number and yield. Plants consistently produced many more flowers with 24 to 30 inch stems. Average yield was increased by 39.7%.
TOMATOES
Work in experimental stations has shown that crop increases of as much as 29% have been obtained by increasing the CO2 concentration. More desirable firmness and more uniform ripening are also observed.
Why you get more rapid and efficient growth and better plant quality with Johnson CO2.
Plants must absorb carbon dioxide (CO2) in combination with water, soil nutrients and sunlight to produce the sugars vital for growth. A shortage of any of these requirements will retard the growing process. Normally there are approximately 300 parts per million of CO2 in the atmosphere; when this level is increased to over 1 ,000 ppm, results are higher production and better plant quality. The Johnson Generator provides up to 1,500 ppm per unit in an average 24' x 200' greenhouse or an equivalent 50,000 cu. ft. volume based on one air change per hour.