为什么吸烟被认为是全球变冷的因素在分析核冬天场景,但透明当分析全球变暖的场景吗?- 江南体育网页版- - - - -地球科学堆江南电子竞技平台栈交换 最近30从www.hoelymoley.com 2023 - 07 - 09 - t01:27:01z //www.hoelymoley.com/feeds/question/18149 https://creativecommons.org/licenses/by-sa/4.0/rdf //www.hoelymoley.com/q/18149 2 为什么吸烟被认为是全球变冷的因素在分析核冬天场景,但透明当分析全球变暖的场景吗? 巴勃罗 //www.hoelymoley.com/users/9635 2019 - 10 - 06 - t19:00:37z 2020 - 01 - 05 - t19:10:05z < p >在许多文章在互联网上(我将列举几个为了问题),大火产生的浓烟(主要由< span class = " math-container " > \ \小美元mathsf{二氧化碳}$ < / span >和CO)核战争后降温的气氛,会引起“核冬天”。< / p > < blockquote > < p >核冬天是一个严重而持久的全球气候变冷效应假设< a href = " https://www.carbonbrief.org/guest-post-did-bombing-during-second-world-war-cool-global-temperature " rel = " nofollow noreferrer " > < / > 1后发生广泛的核战争后引发的大火。[3]的假设是基于事实,这样的火灾可以注入烟尘平流层,可以阻止一些阳光直射到达地球表面。< / p >

Nuclear winter

In the 1980s, using simple climate models, we discovered that global nuclear arsenals, if used on cities and industrial areas, could produce a nuclear winter and lead to global famine.

Smoke from the fires would last for years in the upper atmosphere, blocking sunlight, and making it cold, dark and dry at the Earth’s surface.

Did bombing during second world war cool global temperature

But when we are taking about global warming, oil burning (which releases $\small\mathsf{CO_2}$) contributes towards global warming.

Why is smoke considered a factor in global cooling when analyzing nuclear winter scenarios, but one of warming when analyzing global warming scenarios?

//www.hoelymoley.com/questions/18149/-/18153 # 18153 2 回答的Christoph为什么吸烟被认为是全球变冷的因素在分析核冬天场景,但当分析全球变暖情况不? Christoph //www.hoelymoley.com/users/681 2019 - 10 - 06 - t21:21:35z 2020 - 01 - 05 - t19:08:34z < p >你的假设,“烟”的你的问题,即排放燃烧事件,仅由<跨类= " math-container " > \ \小美元mathsf{二氧化碳}$ < / span >是错误的。至少这不是唯一的因素在起作用。< / p >

During the events you mention, not only $\small\mathsf{CO_2}$ is emitted but also loads of other components such as dust, soot, sulphates and many other things. Especially the particulate components are interesting here. Let's call them dust for simplicity (although that use of the word is not entirely accurate).

During emissions at low altitude (such as driving a car) that dust is quickly removed from the atmosphere and has only local impact. But when enough dust gets into higher layers of the atmosphere, it contributes to cloud formation and causes cooling. If there is enough dust it might even have a direct dimming effect.

$\small\mathsf{CO_2}$ on the other hand only has a warming effect. Also, $\small\mathsf{CO_2}$ remains in the atmosphere for very long times (about 1000 years) whereas dust is removed comparatively quickly.

That is why the scenarios you describe are very different. Also, not all burning has the same ratio of dust to $\small\mathsf{CO_2}$.

Note that the impact of aerosol on climate is a field of intensive study and is included in current climate modelling. There are high uncertainties related to this. My answer should only indicate why the things are different.

//www.hoelymoley.com/questions/18149/-/18154 # 18154 5 答案由Michael Walsby为什么吸烟被认为是全球变冷的因素在分析核冬天场景,但不分析全球变暖的场景吗? 迈克尔Walsby //www.hoelymoley.com/users/17166 2019 - 10 - 06 - t21:25:09z 2019 - 10 - 06 - t21:25:09z < p >这两个派别有不同的点来证明。核灾难派别必须证明核战争一等的将是一场灾难,我不怀疑,而全球变暖派必须证明当前气候变暖事件是由燃烧化石燃料造成的。森林火灾是非常中性,无论取代了烧毁森林里,更多的森林、油棕种植园或传统的农作物,几乎会提取尽可能多的二氧化碳被释放了。< / p >

People with points to prove are apt to get carried away, like the Chicxulub enthusiasts who maintain, against the evidence, that a bolide impact on the Yucatan peninsular caused forest fires on the other side of the globe. CO2 emissions from the Deccan Traps super-volcano are usually ignored as a cause of the extinctions. Think of a million Tambora eruptions rolled into one and you have some idea of the Deccan Traps.

As you may already be aware, you don't need nuclear weopons to set cities on fire. The fire bombing of Tokyo in February 1945 killed 90,000 people, while the nuking of Nagasaki later that year killed 'only' 45,000. There were many such fire bombings during the 2nd World war, yet I have never heard it said that they contributed a meaningful amount of CO2 to global warming. A lot of war industries were also releasing CO2.

One thing I am absolutely certain of is that there has always been climate change and there always will be, and it will not be stopped in its tracks by anything man can do in the 21st century or any other century. Slowed perhaps, but not stopped.

//www.hoelymoley.com/questions/18149/-/18309 # 18309 4 肯费边的回答为什么吸烟被认为是全球变冷的因素在分析核冬天场景,但当分析全球变暖情况不? 肯费边 //www.hoelymoley.com/users/18145 2019 - 10 - 28 - t07:34:40z 2020 - 01 - 05 - t19:07:05z < p >问题包含一个错误假设,气候科学未能考虑气溶胶粒子的冷却效果,包括吸烟,迫使预期原则的核冬天场景。气候科学并试图量化每一个显著的影响,这两个气候变暖和变冷,不仅增加温室气体的温室效应——< span class = " math-container " > \ \小美元mathsf{二氧化碳}$ < / span >。< / p >

Radiative forcings

Whilst not as recent as I would like, the graphic shows the principal climate forcings that climate science has identified and includes the cooling affects of aerosols.

Aerosols from burning forests are short-lived, and the $\small\mathsf{CO_2}$ from burning vegetation should be drawn back down by regrowth, whether forest regrowth or grassland. The most significant, enduring climate consequence of Amazon forest being cleared and burned is not the aerosols or the $\small\mathsf{CO_2}$ from the fires, it is from land clearing turning a large existing Carbon Sink into a carbon source.

Turning the Amazon to savannah would release 200 billion metric tons of $\small\mathsf{CO_2}$. The cooling effect of the aerosols from burning will not persist long, but the raised $\small\mathsf{CO_2}$ levels from the loss of a large Carbon Sink will.

//www.hoelymoley.com/questions/18149/-/18326 # 18326 1 回答由Deditos为什么吸烟被认为是全球变冷的因素在分析核冬天场景,但透明当分析全球变暖的场景吗? Deditos //www.hoelymoley.com/users/106 2019 - 10 - 29 - t21:51:32z 2020 - 01 - 05 - t19:10:05z < p >而主要排放这些火灾<跨类= " math-container " > \ \小美元mathsf{二氧化碳}$ < / span >有限公司,更重要的区别是发生了什么糟糕燃烧碳聚合成较大颗粒的产品。气候社区往往把这些称为黑碳(BC),虽然这是< a href = " https://www.atmos-chem-phys.net/6/3131/2006/ " rel = " nofollow noreferrer " >一个简化< / >。公元前这些粒子是强烈的吸收太阳辐射的能力,导致当地大气加热,但他们也有很短的一生在对流层(~ 5天;< a href = " https://doi.org/10.5194/acp - 15 - 8201 - 2015”rel = " nofollow noreferrer " >贝克et al, 2015 < / >),所以大气中公元前的数量在任何时候相对较小(~ 0.1 Tg)。这整个对流层升温效应,这就是为什么它是包含在计算的历史和未来的温室效应,但它不是一样大的长寿命和丰富的物种如< span class = " math-container " > \ \小美元mathsf{二氧化碳}$ < / span >。< / p > < p >需要注意的一件重要的事情,是有大尺度差异,正常的烟雾排放和核事件。当前BC排放的各种各样的表面燃烧过程是大约7.2 Tg /年(~ 0.02 Tg /天;< a href = " https://www.atmos-chem-phys.net/17/8681/2017/ " rel = " nofollow noreferrer " > Kilmont et al, 2017 < / >)。一个巨大的数字相比~ 0.1 Tg大气负担,但就像我说的,清除过程是快。这些排放分布在大部分的全球土地面积(尽管他们最大的非洲、印度和中国),所以排放单位面积也相对较低。< / p > < p > < >强在公元前一个核子事故排放要大得多,将发生在一个小区域,并注入整个对流层< / >强。例如,< a href = " http://www.atmos-chem-phys.net/7/2003/2007/ " rel = " nofollow noreferrer " > Robock et al(2007) < / >,同样的人你链接问题,跑这模拟:< / p > < blockquote > < p >在我们的标准计算,我们将5月15日5 Tg的黑碳注入一列网格框30 N, 70 e .我们把黑碳模型层中对应于对流层上层(300 - 150 mb)。< / p > < /引用> < p >这是一个巨大的扰动- 50倍当前大气总量和250倍当前日常通量。 They found that the BC entered the stratosphere, where removal processes are much slower than in the troposphere, such that,

E-folding times are 6 y, compared with 1 y for volcanic eruptions and 1 week for tropospheric aerosols.

The BC then absorbs solar radiation and heats the stratosphere, reducing the amount of solar radiation reaching the surface and cooling surface air temperature by more than 1 degree Celsius for about 5 years. Note that the associated $\small\mathsf{CO_2}$ emissions would warm the troposphere, but over a slower time scale and these studies tend to concentrate on the immediate BC cooling effect of a nuclear incident.

As an additional bit of contrast, that study also found that,

When we placed the aerosols in the lower troposphere (907–765 mb), about half of the aerosols were removed within 15 days

This indicates how important it is for the BC emissions to reach the stratosphere in order get a prolonged surface cooling.

//www.hoelymoley.com/questions/18149/-/18334 # 18334 2 答案由f。索普为什么吸烟被认为是全球变冷的因素在分析核冬天场景,但透明当分析全球变暖的场景吗? f.thorpe //www.hoelymoley.com/users/543 2019 - 10 - 30 - t03:25:51z 2020 - 01 - 05 - t19:07:36z < p > Dedito的回答是有效的,但是我想提供一个门外汉的版本。< / p > < p >核冬天的情况下阻止太阳光“烟”(例如颗粒物、不透明的气体如CO和<跨类= " math-container " > \ \小美元mathsf{二氧化碳}$ < / span >)。这导致净全球变冷效应,由于大量的颗粒被困在平流层和阳光反射回太空。驾驶的原则参与这个过程确实是包含在气候模型和全球变暖的预测。然而,“一切照旧”场景的净效应是一个净变暖。< / p > < p >核爆炸产生很多热量,平流层注入颗粒物。大型火山爆发也平流层注入颗粒,通常在气候模型分析讨论。< / p > < p >典型的颗粒物排放(如从汽车、工业等)在对流层存款表面上,在那里他们可以发生化学反应(水),或分散。相比之下,平流层只有分散作为去除颗粒的机理。此外,空气在平流层向下不容易混合对流层,由于对流层顶,缺少水分。 Thus, large heat sources (e.g. nuclear bombs, volcanoes, and megafires) can push particulate into the stratosphere where it stays trapped for years.

Baidu
map