Over the past two decades, there has been a growing appreciation ...
Here's a look at some of the trends young people have made popular over the past five decades.
With increased National Doppler radar coverage, increasing population, and greater attention to tornado reporting, there has been an increase in the number of tornado reports over the past several decades. This can create a misleading appearance of an increasing trend in tornado frequency. To better understand the variability and trend in tornado frequency in the United States, the total number of EF-1 and stronger, as well as strong to violent tornadoes (EF-3 to EF-5 category on the Enhanced Fujita scale) can be analyzed. These tornadoes would have likely been reported even during the decades before Doppler radar use became widespread and practices resulted in increasing tornado reports. The bar charts below indicate there has been little trend in the frequency of the stronger tornadoes over the past 55 years.
Shanghai: Shanghai isn’t a new city. The major port has long been China’s second city after the capital of Beijing, as well as its chief portal to the outside world. But the changes Shanghai has undergone over the past two decades dwarf those experienced by almost any other city in the world. Shanghai’s population has grown from 13.3 million in 1990 to over 23 million in 2010. The city has sprawled out from its historic center at the mouth of the Yangtze River, with new developments gobbling up ancient farmland and villages. The Timelapse images above show Shanghai as an urban stain expanding relentlessly in all directions.
over the past decades or over the last decade
a trend that has continued over the past four decades
The city has exploded over the past few decades, sprawling into the desert—even as a growing population and worsening drought shrink nearby Lake Mead.The largest lake in the Middle East, this saline body of water has been drying up over the past few decades because of drought and overconstruction.A warming climate has helped cause this Alaskan glacier to retreat by nearly 2 miles over the past few decades. As the Arctic warms, will glaciers become a thing of the past?What’s truly amazing — and perhaps alarming — about this new era of extreme resources is how fast they’re developing. My visit to the Albertan oil sands came late in 2010. In the two and a half years since, oil companies there have produced nearly a billion new barrels of crude. As time-lapse satellite images show, much of this development is relatively new, a response to the sharp increase in the price of oil over the past decade. Similar trends are also at work in the vast coalfields of the Powder River Basin in Wyoming, the mountaintop mines of West Virginia and the rain forests of the Brazilian state of Rondonia. A growing global population and a ravenous demand for natural resources is altering the very face of the planet. Thanks to the Timelapse imagery, we can see it happening. Over the past three decades, childhood obesity rates in America have tripled, and today, nearly one in three children in America are overweight or obese. The numbers are even higher in African American and Hispanic communities, where nearly 40% of the children are overweight or obese. If we don't solve this problem, one third of all children born in 2000 or later will suffer from diabetes at some point in their lives. Many others will face chronic obesity-related health problems like heart disease, high blood pressure, cancer, and asthma. Because each individual source of readily available data on income distribution has different advantages and limitations, no single source illustrates all of the major trends in inequality over the past six decades or so. Ideally, we would look at a comprehensive measure of income that covers a long time span, allows us to compare before- and after-tax income at different points in the income distribution, and accounts for changes in the size and composition of households. CBO data satisfy most of these criteria but only go back to 1979; the historical Census family income data series and Piketty-Saez income concentration data cover a longer time span but use less-comprehensive measures of income and do not adjust for changes in the size and composition of households.