大家好，这里是湖北理工学院外国语学院英语调频广播台，我是主播张欣。今年夏天可以说是格外的炎热，与往常相比高了好几度。全球普遍高温，许多人也因为热射病而死。有人说这将是未来夏天里最凉快的一年，天气真的变得越来越极端了吗？
首先让我们先来了解一下这篇文章里出现的一些重点词汇
meteorologists [mi:ti:ə'rɔlədʒi : z ] n．气象学
rampant [ˈræmpənt] adj．猖獗的；蔓延的；猛烈的；［纹］跃立的
cyclones [ˈsaɪkləʊnz] n. 旋流器
current [ˈkʌrənt] n．趋势；（水、气、电）流adj．现在的；流通的
precipitation [prɪˌsɪpɪˈteɪʃn] n．仓促；急躁；沉淀；降雨量；坠落；凝结；冰雹
humidity [hjuːˈmɪdəti] n．湿度；湿气
chaotic [keɪˈɒtɪk] adj．混乱的
turbulent [ˈtɜːbjələnt] adj．狂暴的；骚动的；动荡的；汹涌的
parameter[pəˈræmɪtə(r)] n．参数
constraints [kənˈstreɪnt] n．强制；被约束；拘束
Is the weather really getting more extreme?
天气真的变得越来越极端了吗？
From 2016 to 2019, meteorologists saw record - breaking heat waves around the globe rampant wildfires in California and Australia ,and the longest run of category 5 tropical cyclones on record.The number of extreme weather events has been increasing for the last 40 years , and current predictions suggest that trend will continue .
在2016到2019年间，气象学家在全球观测到了前所未有的热浪，加利福尼亚洲与澳大利亚山火肆虐， 五级热带飓风的持续时间也创下了纪录。过去40年来，极端天气事件发生的次数在持续增加，而当前的预测表明，这一趋势还会继续下去。
But are these natural disasters simply bad weather ? Or are they due to our changing climate ? To answer this question we need to understand the differences between weather and climate -- what they are , how we predict them , and what those predictions can tell us .
但这些自然灾害仅仅是“天气不好”吗？还是源自我们的气候变化？要回答这个问题，我们首先要理解天气与气候之间的区别﹣﹣它们是什么？如何进行预测？预测结果又代表了什么？
Meteorologists define weather as the conditions of the atmosphere at a particular time and place .Currently , researchers can predict a region＇s weather for the next week with roughly 80% accuracy .Climate describes a region＇s average atmospheric conditions over periods of a month or more . Climate predictions can forecast average temperatures for decades to come , but they can＇t tell us what specific weather events to expect .
气象学家将“天气”定义为在某个特定时间及地点的大气状况。目前，研究人员能够以大约80％的准确率预测出某个地区接下来一周的天气。“气候”描述的则是某个地区在一个月或以上的时间段内的平均大气状况。预测能够预估未来数十年的平均气温，但无法预测可能发生的具体天气事件。
These two types of predictions give us such different information because they＇re based on different data . To forecast weather , meteorologists need to measure the atmosphere＇s initial conditions . These are the current levels of precipitation , air pressure , humidity , wind speed and wind direction that determine a region＇s weather .
这两种预测之所以能提供如此不同的信息，是因为它们分别基于不同的数据。 在预测天气时，气候学家要测量大气的初始状况。当前的降水量、气压、湿度、风速及风向，决定了该地区的天气状况。
Twice every day , meteorologists from over 800 stations around the globe release balloons into the atmosphere . These balloons carry instruments called radiosondes , which measure initial conditions and transmit their findings to international weather centers . Meteorologists then run the data through predictive physics models that generate the final weather forecast .
来自全球800多个气象站的气候学家每天会向大气中释放两次探空气球。这些气球搭载的仪器叫做“无线电探空仪”，它会测量大气的初始状况，然后将结果传送给国际气象中心。气象学家将数据输进物理预测模型，生成最终的天气预报。
Unfortunately , there＇s something stopping this global web of data from producing a perfect prediction :weather is a fundamentally chaotic system .This means it＇s incredibly sensitive and impossible to perfectly forecast without absolute knowledge of all the system＇s elements .In a period of just ten days , even incredibly small disturbances can massively impact atmospheric conditions making it impossible to reliably predict weather beyond two weeks .
遗憾的是，某件事情妨碍了这张全球数据网做出完美的预测：天气本质上是一个混沌系统。这意味着它极度敏感，若没有对系统中所有因素了如指掌，就不可能做出完美的预测。在短短的十天内，即便是极度微小的干扰，也能对大气状况造成巨大的影响，因此，要准确预测两周以后的天气是不可能的。
Climate prediction , on the other hand , is far less turbulent . This is partly because a region＇s climate is , by definition , the average of al its weather data . But also because climate forecasts ignore what＇s currently happening in the atmosphere , and focus on the range of what could happen .These parameters are known as boundary conditions , and as their name suggests , they act as constraints on climate and weather .
相对而言，气候预测则远没有这么大的不确定性。部分原因在于，气候的定义本身就是一个地区所有天气数据的平均值。除此以外，气候预测会忽略大气当前的状况，而注重可能出现的大气状况的范围。这些参数被称为“边界条件”，顾名思义，它们代表了气候及天气状况的边界限制。
One example of a boundary condition is solar radiation . By analyzing the precise distance and angle between a location and the sun , we can determine the amount of heat that area will receive .And since we know how the sun behaves throughout the year , we can accurately predict its effects on temperature . Averaged across years of data , this reveals periodic patterns , including seasons . Most boundary conditions have wel l - defined values that change slowly , if at all . This allows researchers to reliably predict climate years into the future .
边界条件的一个例子是太阳辐射。通过分析某个地区与太阳间的精确距离和角度，我们就能判断该地区所接收的热量。既然我们知道一年中太阳的运行模式，就能够准确地预测它对气温的影响。对多年的数据取平均值后，就能发现周期性规律，例如季节。边界条件的数值大多定义明确、变动很慢，甚至完全不变。因此，研究者能对未来数年的气候做出可靠的预测。
But here＇s where it gets tricky . Even the slightest change in these boundary conditions represents a much larger shift for the chaotic weather system . For example , Earth＇s surface temperature has warmed by almost 1 degree Celsius over the last 150 years .This might seem like a minor shift , but this 1-degree change has added the energy equivalent of roughly one million nuclear warheads into the atmosphere . This massive surge of energy has already led to a dramatic increase in the number of heatwaves , droughts , and storm surges .
但问题来了。这些边界条件即使发生极其微小的变化，也对混沌的天气系统产生巨大的扰动。例如，过去150年以来，地球的表面温度上升了将近1摄氏度。 这变化看似微小，但这1摄氏度的变化向大气层中释放的能量相当于约100万颗核弹。这一波巨大的能量已导致了热浪、干旱及风暴潮的数量急剧增加。
So , is the increase in extreme weather due to random chance , or changing climate ?The answer is that -- while weather wil always be a chaotic system -- shifts in our climate do increase the likelihood of extreme weather events .Scientists are in near universal agreement that our climate is changing and that human activity is accelerating those changes .
那么，极端天气的增长究竟是出于偶然还是气候变化？答案是﹣﹣虽然天气系统永远是混沌的，但气候变化确实会增加极端天气事件的概率。 科学家们几乎一致同意，我们的气候在产生变化，且人类活动正在加剧这些变化。
But fortunately , we can identify what human behaviors are impacting the climate most by tracking which boundary conditions are shifting .So even though next month＇s weather “ might always be a mystery , we can work together to protect the climate for centuries to come .
所幸，我们能通过追踪哪些边界条件发生了变动，来判断哪些人类行为对气候造成的影响最大。所以，虽然下个月的天气可能始终是个谜，但我们仍然可以为共同保护未来数百年的气候而努力。
今天的节目到这里就结束了，想要获取音频回放以及更多完整版稿件，请到湖北理工学院外国语学院英语语言学习示范中心自行了解http://sfl.hbpu.edu.cn/sfzx/cxxm/dpgb.htm，我是主播张欣，我们下期再见。
