| استرس های گرمایی: ما تا کجا سازگاریم؟ | | Print | |
| Climate Change - مبانی و مباحث علمی - Climate Science |
| Written by Behrooz Hassani M |
| Wednesday, 08 December 2010 10:10 |
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امروز فرصتی شد که با دوستی در مورد مدلی صحبت کنیم. در حین صحبت خبر از مجموعه مطالعات جدیدی داد که موضوع استرس های گرمایی را مورد توجه قرار می دهند. این استرس ها که در صورت افزایش متوسط دمای کره ی زمین تهدید جدی برای کیفیت حیات انسان محسوب می شوند می توانند در نقاطی که میزان رطوبت بالا است خطرات جدی را برای انسان ها ایجاد کنند. در واقع شرایط به گونه ای می شود که علاوه بر گرمای وارده بر بدن، به دلیل بالا بودن رطوبت، عرق تبخیر نشده و از این طریق بدن خنک نمی شود. درست مثل اینکه شما قرار باشد برای مدت زیادی در تب چهل درجه بمانید. به عبارت دیگر صحبت از این است که افزایش گرما به این راحتی ها که فکر می کنیم قابل تحمل نیست و ممکن است شرایط به مرز غیرقابل تحمل و سازگاری برسد. در مورد این استرس های گرمایی دو سه مرجعی درج می کنم که مربوط به سال جاری هستند. اگر دوستان علاقمند به یک حوزه ی پژوهشی جدید هستند به نظرم زمینه ی جالبی باشد.
AbstractDespite the uncertainty in future climate-change impacts, it is often assumed that humans would be able to adapt to any possible warming. Here we argue that heat stress imposes a robust upper limit to such adaptation. Peak heat stress, quantified by the wet-bulb temperature TW, is surprisingly similar across diverse climates today. TW never exceeds 31 °C. Any exceedence of 35 °C for extended periods should induce hyperthermia in humans and other mammals, as dissipation of metabolic heat becomes impossible. While this never happens now, it would begin to occur with global-mean warming of about 7 °C, calling the habitability of some regions into question. With 11–12 °C warming, such regions would spread to encompass the majority of the human population as currently distributed. Eventual warmings of 12 °C are possible from fossil fuel burning. One implication is that recent estimates of the costs of unmitigated climate change are too low unless the range of possible warming can somehow be narrowed. Heat stress also may help explain trends in the mammalian fossil record.
McMichael, A.J. and Dear, K.B.G., (2010) "Climate Change: Heat, Health, and Longer Horizons", Proceedings of the National Academy of Sciences of the United States of America, Vol. 107, No. 21, 25 May, pp. 9483-9484. [http://www.pnas.org/content/107/21/9483.short]. Public concern over climate-change impacts has mostly focused on the economic, physical, and political domains. The consequences for various industries, agriculture, livelihoods, national gross domestic product, property, infrastructure, and electoral prospects have captured most attention. In this issue of PNAS, Sherwood and Huber (1) apply a longer than usual perspective on climate change and conclude that, because of limits to human tolerance of heat, much of Earth’s surface may not be habitable by 2300. Their important, related, and overarching statement is that “current assessments are underestimating the seriousness of climate change” (1). They argue that, whereas high-profile threats such as sea-level rise and economic slowdown have caused widespread anxieties, their impacts on human communities would pale into insignificance in a world that might, thermally, become partly or wholly uninhabitable by humans...
کلمات کلیدی:
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Sherwood, S.C. and Huber, M., (2010) "An Adaptability Limit to Climate Change Due to Heat Stress", Proceedings of the National Academy of Sciences of the United States of America, Vol. 107, No. 21, May 25, 2010, pp. 9552-9555. [