Thursday, April 24, 2014
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飓风桑迪和气候变化

佐治亚州阿森斯——在北美飓风季逐渐减弱的时候,超级风暴按理不该再对美国东海岸造成大规模的破坏,而飓风桑迪却在此时提醒人们极端天气事件到底有多严重。作为2012年飓风季中心气压最低的飓风,桑迪可能已经造成了高达200亿美元的损失,也因此成为史上破坏力最强的飓风之一。

桑迪与从东部顶头而来的天气系统相互影响,为预报员出了一道极大的难题,也为该地区带来了几乎前所未有的天气条件。类似的风暴大约20年前袭击了新英格兰。但桑迪更胜一筹,伴随着飓风和倾盆大雨,并在人口众多的大西洋沿岸中部及东北走廊造成了若干沿海洪灾。

有些人理所当然地会把桑迪和气候变化联系起来。美国近年爆发巨型龙卷风后有人就急于做出这样的判断,即使科学文献并没有对这种联系给出有说服力的支撑。因此从气候变化的角度来看,我们最好先对桑迪做出审慎的评估,以免草率反应对科学的可信性造成伤害。

但并没有理由因此而感到安慰。按照巨型保险企业慕尼黑再保险公司的统计,2011年由于全球天气和气候灾害造成的损失超过三分之一万亿美元,而今年的损失总额或许也毫不逊色。越来越多的证据表明气候变化和海平面上升、热浪、干旱和降雨强度之间的确具有某种联系,而且尽管对飓风和龙卷风的科学研究还无法得出确凿的结论,但这种情况也有可能改变。

其实,联合国政府间气候变化专门委员会(IPCC)和其他科学文献近期的报告表明水体变暖会增强热带气旋(即台风)的强度。我们的大气和海洋其实正在变暖,海洋中大量储存的余热会在未来的某个时点释放。某些研究甚至表明热带气旋可能会更加“多雨”。可以肯定海平面由于气候变化的作用已经在上个世纪上升,并且还将继续升高。现在的风暴潮发生在已经升高的海平面上,因此导致所到之处的洪灾损失大幅增加。

美国东北部沿岸的海表温度比平均温度高出约华氏五度,这让桑迪在登陆前就积聚了更多的能量。此时就将风暴严重程度与海表温度升高联系在一起似乎还为时尚早,因为不同区域的情况一般会有所不同。但这种联系从道理上肯定说得通。

此外,美国东北部沿海的海平面升高速度快于全球平均速度的4倍,这使上述地区更容易遭受洪水和风暴潮。而问题的最低限度是海平面上升导致任何沿海风暴系统将带来更大的水量。

还有一点需要提起注意,那就是名为“阻塞”(block)的持续性高压大气模式有可能导致格陵兰岛冰盖出现创纪录融化,也最有可能因此导致桑迪没有移向海平面,而是进入内陆。现在就确定这种阻塞模式是否是天气变化、短期气候变化或气候变化结果的表现似乎还不到时候。

过去的几十年数值天气预报的发展使我们能更好的“预见”未来。1938年9月在取得所有这些进展之前,一场飓风摧毁了绝大部分新英格兰。这场飓风来临之前没有发出任何警告。而今天,多亏卫星、气象气球、超级计算机和经验丰富的气象预报人士,我们提前一个星期就能预见灾害性天气的到来。由于方法改进和数据升级,在气候建模领域也取得了类似的进展。

至少我们必须确保世界级的天气和气候模拟中心拥有必要的资金和人力资源来落实最先进的预测技术。虽然最初数值天气预报发端于美国,但今天其他国家也逐步建立起极高的建模能力。比方说英国的欧洲中程天气预报中心,抢在美国最佳模型几天前就锁定东海岸是桑迪的登陆目标。

随着气候变化开始影响并加剧极端天气事件,世界各国为了争取备灾所需的时间,就必需在未来几年内加强合作。我们还需要能够提高预测能力的政府、私营部门以及学术界的合作。

科学会议是交流研究心得、验证新方法和达成新伙伴关系的重要讨论场所。很多科学会议具有国际性,我们需要鼓励这样的交流,即使在政府预算比较​​艰难的时期也不例外。如果没有通过这种国际合作所得到的知识和能力,我们不妨扪心自问我们能否预测或评估像桑迪这样的风暴。

我们不清楚像桑迪这样的超级风暴是否预示着气候变化和极端天气事件之间令人不安且不可预测关系的“全新常态”。但这并不是说这样的关系不存在或不可能存在,而是说必需实际进行证明(或否定)其存在的科学研究。科学就是要这样发挥作用。桑迪为我们提供了需要支持科学发展的有力的示范。

翻译:Xu Binbin

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  1. CommentedFrancisco Alves

    There is no "new normal". "Normal" can only exist when it is not influenced by external factors. Let's just stop looking at the tree. When we look around again the forest will be gone and that tree with it.

  2. CommentedZsolt Hermann

    The problem is when ever we enter these debates, personal or group interest immediately trigger reflex responses to sweep the data and facts under the carpet.
    The greatest effort is put into denying the human contribution to these changes, to lessen any responsibilities from our part.
    And it is not just from strong interest groups, or corporations, but from everybody, none of us would like to accept that we have a negative effect on the world around us.
    But we cannot deny what is happening, it is not only the tropical storms, but the geothermal activity all around the globe with rising number, and intensity of volcano activity and earthquakes are also on our account,and despite people calling the extreme summer temperatures all over Europe for example "heat-waves", I do not think we can use such expressions when those temperature are the up 5 years in a row, and steadily rising.
    And in terms of human involvement we really only scratching the surface.
    If we try to look at it from the dynamic point of view of ecosystems then we see a much starker picture.
    There is no denying that the whole Earth, and possibly the Universe is a single, living ecosystem, with a very intricate interconnections, combination of forces, and laws primarily aimed at one thing: maintaining an overall balance and homeostasis in order to maintain structure, and in the case of living organism, growth, life.
    If we look at the inanimate, vegetative and animal levels of nature, each and every part, species, organism is automatically, instinctively in balance with this ecosystem, absorbing, emitting the necessary amount for survival, and reproduction, but never beyond.
    If for some reason any species could not maintain this equilibrium, they did not survive evolution.
    There is also no denial that the human species is way beyond its necessities, absorbing and emitting from and into the natural system materials that are multiple times over the natural necessities for survival and reproduction, and this imbalance, and opposition to the natural system has reached its maximum recently in the form of the excessive, overproduction, over consumption constant quantitative growth model, reaching and leaving peak points in exhausting human and natural resources.
    At the same time, again opposed to any other living species, humans live based on opposing and exploiting each other to the point of eradicating nations, cultures.
    The "human cancer" reached end stage.
    Most people would look at nature as "mindless" or random, but it is not the case, the forces and laws of balance and homeostasis, self-adjustment are working tirelessly, otherwise the system could not exist. And there is no appeal process here, the laws of nature are absolute.
    In conclusion we could say that at the moment the vast natural system around humanity, which system is infinitely larger and stronger than human beings, started fighting back, and is prepared to reject this harmful species as a foreign body. The imminent collapse of the unnatural, unsustainable financial, economical system is just another sign how nature self-corrects, removing unnatural, harmful processes, regardless of what tricks, "solutions" we think we have up in our sleeves.
    The blows that are likely to quicken and intensify are not comparable to even the harshest nuclear wars humans can come up with, we are facing forces we cannot even comprehend or predict.
    The system is not going to change, it has to maintain, preserve its integrity, only humans can learn, understand and adjust, this capability elevates us above other lifeforms, and give as the capability to become the benevolent "rulers" of this system, being partners with it.
    The question is whether this adaptation is coming in the form of wise understanding and conscious, pro-active manner, or as a result of the blows, falling on our knees.

  3. CommentedBoris Krumov

    What about the HAARP and the chemtrails then ? Should we accept them as something "normal" in the light of the said things ?
    Make no mistake, we know what has really happened !

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