在布拉格观察到破纪录的气候变化，而不是在费城

在布拉格观察到破纪录的气候变化，而不是在费城

对气候变化越来越多的关注意味着创纪录的平均气温肯定会是一条大新闻，但这到底是因为全球变暖导致破纪录的事件经常发生呢？还是仅仅不过是统计学上不相关的正常波动呢？美国的物理学家们认为这个问题最简单的回答是：这依赖于某一特定地区的气温变化历史数据积累的多少。对布拉格和费城两地气温数据的分析表明，全球变暖效应正在变得越来越明显，而之前的130年的气温记录基本保持不变。

Climate-change breaks records in Prague, not Philadelphia (Jan 11)
http://physicsweb.org/article/news/11/1/7

Growing concern about climate change means that record-breaking
temperatures are big news -- but is global warming making
record-breaking events more common, or are they unrelated statistical
fluctuations? The simple answer, according to physicists in the US, is
that it depends on how long historical temperature data have been
gathered for a specific locale. The analysis of temperature data from
Prague and Philadelphia suggests that the effects of global warming
become apparent after about 130 years of record keeping.