By Matt Siegel

24 May 2013 (National Geographic News) – In early 2012 once-in-a-century floods submerged swaths of Great Britain and Ireland, causing some $1.52 billion in damages. Then in June record-high temperatures in Russia sparked wildfires that consumed 74 million acres of pristine Siberian taiga. Months after that, Hurricane Sandy pummeled seven countries, killing hundreds and running up an estimated $75 billion in damages. Just this week, a tornado of virtually unheard of size and ferocity tore through a small city in Oklahoma, leaving 24 people dead. Each of these one-off traumas was bad enough, wreaking havoc, but in Australia such events seem to be becoming commonplace. The Lucky Country has experienced a major spike in extreme weather in the past few years, with a string of devastating incidents just since January. That has people wondering if the island continent is somehow a perfect bellwether for the Earth’s changing climate. So scientists are bearing down on the problem with intensity, investigating Australia’s increasingly violent weather patterns and trying to figure out what they might portend for the rest of the world as our climate changes. The rough-hewn sandstone buildings perched atop Observatory Hill have been keeping an eye on Sydney Harbor since 1858. They’ve pretty much seen it all—from the installation of the city’s first gaslights to the construction of the now iconic Sydney Opera House and Harbor Bridge. But at 2:55 p.m. on 18 January 2013, meteorological equipment in the observatory registered something new: a read-out marking the hottest day in the city’s history: 45.8°C (114.4°F). Much of the continent was languishing in the grip of a heat wave that would break 123 heat and flood-related records in 90 days—among them, the hottest summer on record and the hottest seven consecutive days ever recorded. At the time these statistical dramas, and their possible significance, paled against the imperative of not self-combusting on your walk from office to car. At the Pink Roadhouse in the outback town of Oodnadatta—whose locals are legendary for the stoicism with which they have long dealt with living in Australia’s hottest town—temperatures pushed so high that gasoline vaporized before it even made it into the fuel tank. “The ground, the building, everything is so hot, you walk outside and you feel it’s going to burn you,” Lynnie Plate, the exhausted owner of the establishment, told a reporter at the time. The national record of 50.7°C (123.2°F) set in Oodnadatta in January 1960 stayed intact, just barely. Australians love their summer heat. They take particular joy in mocking British tourists for the magenta hue they often acquire after even a mild day at the beach. Because winter and summer temperature variations aren’t all that great in much of Australia, Aussies, unlike the Brits, are habitually accustomed to heat that might melt lesser mortals. But when 8 of the 21 days in the last 102 years on which Australia averaged a high of more than 39°C (102°F) happened to occur in 2013, people weren’t charmed. The anomaly stood out. Numbers like those break through what climate scientists like David Jones, manager of climate monitoring prediction at the Australian Bureau of Meteorology, call the “signal to noise” ratio. “One of the first places on the planet where the global warming signal is easy to discern is actually Australia, because of this low temperature variability,” Jones said. “And that’s exactly what we’re seeing. The Australian warming trend is very clearly apparent in our records. It pops out quite quickly from the background noise of weather patterns.” But just what does that breaking through the noise tell us? Apparently, it says not to expect things to calm down any time soon. [more]