History

In dozens of archaeological discoveries around the world, from the once-successful reservoirs and canals of Angkor Wat in Cambodia to the deserted Viking colonies of Greenland, new evidence paints pictures of civilizations struggling with unforeseen climate changes and the reality that their farming practices had become unsustainable. Among these discoveries are also success stories, where ancient farming practices helped civilizations survive the hard times. Zuni farmers in the southwestern United States made it through long stretches of extremely low rainfall between A.D. 1200 and 1400 by embracing small-scale, decentralized irrigation systems. Farmers in Ghana coped with severe droughts from 1450 to 1650 by planting indigenous African grains, like drought-tolerant pearl millet. Ancient practices like these are gaining new interest today. As countries face unprecedented heat waves, storms and melting glaciers, some farmers and international development organizations are rea...

Strong winds blew across mountain slopes after a record-setting warm, dry summer. Small fires began to blow up into huge conflagrations. Towns in crisis scrambled to escape as fires bore down. This could describe any number of recent events, in places as disparate as Colorado, California, Canada and Hawaii. But this fire disaster happened over 110 years ago in the Northern Rocky Mountains of Idaho and Montana. The “Big Burn” of 1910 still holds the record for the largest fire season in the Northern Rockies. Hundreds of fires burned over 3 million acres – roughly the size of Connecticut – most in just two days. The fires destroyed towns, killed 86 people and galvanized public policies committed to putting out every fire. Many residents of Wallace, Idaho, fled on trains ahead of the 1910 blaze. Volunteers who stayed saved part of the town, but about a third of it burned. R.H. McKay/U.S. Forest Service...

Fifty years ago, a secret deal among Arab governments triggered one of the most traumatic economic crises to afflict the United States and other big oil importers. Saudi King Faisal and other Arab leaders launched an oil embargo on Oct. 17, 1973, as payback for Washington siding with Israel in its war with neighboring Egypt and Syria. The oil market hostilities arose from a pact between Faisal and the leaders of Egypt and Syria, whose armies planned surprise drives to retake their territory under Israeli occupation. If the United States intervened to assist Israel, Faisal and other Arab producers agreed to retaliate with the “oil weapon.” When Washington airlifted in U.S. weapons that helped Israel thwart Arab gains, Faisal and OPEC’s Arab members retaliated. They increased oil prices, banned oil shipments to the United States and cut production by 5% per month. The ensuing economic and political carnage is legendary. The embargo catalyzed a long period of...

Images of orange groves and Spanish-themed hotels with palm tree gardens filled countless pamphlets and articles promoting Southern California and Florida in the late 19th century, promising escape from winter’s reach. This vision of an “American Italy” captured hearts and imaginations across the U.S. In it, Florida and California promised a place in the sun for industrious Americans to live the good life, with the perfect climate. But the very climates that made these semitropical playgrounds the American dream of the 20th century threaten to break their reputations in the 21st century. A postcard illustrates the latest style for Miami beach bathing around 1920. Asheville Post Card Co./Wikimedia In California, home owners now face dangerous heat waves, extended droughts that threaten the water supply, and uncontrollable wildfires. In Florida, sea level rise is worsening the risks...

About 400,000 years ago, large parts of Greenland were ice-free. Scrubby tundra basked in the Sun’s rays on the island’s northwest highlands. Evidence suggests that a forest of spruce trees, buzzing with insects, covered the southern part of Greenland. Global sea level was much higher then, between 20 and 40 feet above today’s levels. Around the world, land that today is home to hundreds of millions of people was under water. Scientists have known for awhile that the Greenland ice sheet had mostly disappeared at some point in the past million years, but not precisely when. In a new study in the journal Science, we determined the date, using frozen soil extracted during the Cold War from beneath a nearly mile-thick section of the Greenland ice sheet. A brief look at the evidence beneath Greenland’s ice sheet and the lessons its holds. The timing – about 416,000 years ago, with largely ice-free conditions last...