In the fall of 1992, a construction crew made an unusual discovery during a freeway expansion in a coastal area of San Diego County. Buried deep within the silty soil were the bones, tusks, and molars of a mastodon, an elephant-like mammal that once lived in North America. When archaeologists took a closer look, they found signs that humans had battered the animal shortly after its death with the large stones buried alongside it.
But the real surprise came when geologists determined the age of the bones. Radiometric dates showed the mastodon had been buried for about 130,000 years. If correct, this means that ancient humans were in coastal California many tens of thousands of years before they were thought to be in the Americas.
The Arctic Ocean may look inhospitable, but it teems with life along its coasts and within the unexpected, ice-free oases brimming with seabirds gorging on plankton and krill. Despite the anchor these places provide for many of the planet’s birds, whales and marine mammals, almost none have a spot on the World Heritage list, a jaw-dropping catalogue of wonders maintained by the United Nations Educational, Scientific and Cultural Organization (UNESCO).
Now a group of global scientists want to fix that oversight. On Tuesday, the International Union for the Conservation of Nature, made up of more than 170 countries, government agencies, and more than 1,000 conservation groups, singled out seven Arctic marine sites that could potentially qualify for UNESCO World Heritage status.
More than 1,000 sites around the world have earned the UNESCO designation, based on their “outstanding universal value,” including the Grand Canyon and the Great Barrier Reef, the Leaning Tower of Pisa, and China’s Great Wall. Yet only five sites are found within the limits of the Arctic Circle, and only one of them, Russia’s Wrangel Island Reserve, is a marine site, frequented by hundreds of thousands of Pacific walrus and serving as the summer feeding grounds for some visiting humpback whales from Baja California, Mexico.
A consortium of countries are meeting in Iceland, where they hope to strike a deal that protects the newly accessible ecosystem
The Arctic Ocean has long been the least accessible of the world’s major oceans. But as climate change warms the Arctic twice as fast as anywhere else, the thick sea ice that once made it so forbidding is now beating a hasty retreat. Since 1979, when scientists began using satellites to track changes in the Arctic sea-ice expanse, its average summertime volume has dropped 75 percent from 4,000 cubic miles to 1,000 cubic miles. By September, the Arctic Ocean will have swapped nearly 4 million square miles of ice for open ocean.
This accelerated transformation has troubled scientists, conservationists and government officials who are anxious about the fate of the fish that may live in these waters—and for the entire ecosystem itself. At the center of the Arctic Ocean is a 1.1 million square-mile “donut hole,” surrounded by Canada, the Danish territory of Greenland, Norway, Russia and the United States. The donut hole does not fall under any country’s jurisdiction, and it may well be the last unexploited fishery on Earth. According to international law, anyone could fish these newly opening high seas, if they desired, and thanks to the retreating ice, they may soon have their chance.
One morning in July 2005, Amy Mundorff rode into the Bosnian countryside, tagging along with a team from the International Commission on Missing Persons. The roads wound past forests, farmland and villages. The group stopped near a filed in a hilly area on the outskirts of a village to meet an informant. From the gestures and the translator’s comments, Mundorff understood that the ground beneath the field might hold bodies.
The war in Bosnia-Herzegovina had ended 10 years earlier, but thousands of people remained missing, many presumed buried in hidden graves scattered across the country. Mundorff, a forensic anthropologist wanted to learn how the team excavated and exhumed graves, and then sorted and identified the co-mingled human remains–her area of expertise.
Backhoes scraped away the topsoil, peeling back the earth inches at a time. “they just dug and dug and dug,” recalls Mundorff. Once in a while, the machinery operators would stop and call over an investigator. “It was never anything human. There were roots, animal bones, rocks…but there were no graves,” says Mundorff. By the end of the day, the entire hillside had been dug up, and the team found nothing.
Witness and survivor testimonies remain the most reliable way to locate hidden graves, but the approach is not foolproof. Many of the conflicts under investigation occurred years ago. Elderly witnesses may have fading memories that offer incomplete or incorrect accounts of atrocities. Sometimes the geography of a place changes. Roads get rerouted, forest are cleared, and the edges of villages expand.
Mundorff knew from her own searches for buried murder victims in the United States that investigators often fail to locate hidden graves, but she didn’t expect it to be so difficult in Bosnia-Herzegovina: The country is smaller than Louisiana, and the whereabouts of 8,000 people remain unknown.
“Even if we didn’t find that one grave, I thought we would find something because…where are they?” says Mundorff. She was disappointed and frustrated. “I thought, ‘God, there has to be something better out there.’”
Rising temperatures are threatening urban areas, but efforts to cool them may not work as planned.
The greenhouses that sprawl across the coastline of southeastern Spain are so bright that they gleam in satellite photos. Since the 1970s, farmers have been expanding this patchwork of buildings in Almería province to grow produce such as tomatoes, peppers and watermelons for export. To keep the plants from overheating in the summer, they paint the roofs with white lime to reflect the sunlight.
That does more than just cool the crops. Over the past 30 years, the surrounding region has warmed by 1 °C, but the average air temperature in the greenhouse area has dropped by 0.7 °C. It’s an effect that cities around the world would like to mimic. As Earth’s climate changes over the coming decades, global warming will hit metropolitan areas especially hard because their buildings and pavements readily absorb sunlight and raise local temperatures, a phenomenon known as the urban heat island effect. Cities, as a result, stand a greater chance of extreme hot spells that can kill. “Heat-related deaths in the United States outpace — over the last 30 years — all other types of mortality from extreme weather causes,” says Kim Knowlton, a health scientist at Columbia University in New York. “This is not an issue that is going away.”
Some cities hope to stave off that sizzling future. Many are planting trees and building parks, but they have focused the most attention on rooftops — vast areas of unused space that absorb heat from the Sun. In 2009, Toronto, Canada, became the first city in North America to adopt a green-roof policy. It requires new buildings above a certain size to be topped with plants in the hope that they will retain storm water and keep temperatures down. Los Angeles, California, mandated in 2014 that new and renovated homes install ‘cool roofs’ made of light-coloured materials that reflect sunlight. A French law approved in March calls for the rooftops of new buildings in commercial zones to be partially covered in plants or solar panels.
But the rush to act is speeding ahead of the science. Although cool roofs and green roofs can strongly curb temperatures at the tops of buildings, they do not always yield benefits at the street level, and they may trigger unwanted effects, such as reducing rainfall in some places. “There was a notion that the community had reached a conclusion and there was a one-size-fits-all solution,” says Matei Georgescu, a sustainability scientist at Arizona State University in Tempe. “But that is not the case.”
