The ‘great dying’: rapid warming caused largest extinction event ever

The ‘great dying’: rapid warming caused largest extinction event ever

SOURCE: The Guardian DATE: December 6, 2018 SNIP: Rapid global warming caused the largest extinction event in the Earth’s history, which wiped out the vast majority of marine and terrestrial animals on the planet, scientists have found. The Permian mass extinction, known as the “great dying”, occurred around 252m years ago and marked the end of the Permian geologic period. The study of sediments and fossilized creatures show the event was the single greatest calamity ever to befall life on Earth, eclipsing even the extinction of the dinosaurs 65m years ago. Up to 96% of all marine species perished while more than two-thirds of terrestrial species disappeared. The cataclysm was so severe it wiped out most of the planet’s trees, insects, plants, lizards and even microbes. The great dying event, which occurred over an uncertain timeframe of possibly hundreds of years, saw Earth’s temperatures increase by around 10C (18F). Oceans lost around 80% of their oxygen, with parts of the seafloor becoming completely oxygen-free. Scientists believe this warming was caused by a huge spike in greenhouse gas emissions, potentially caused by volcanic activity. “It does terrify me to think we are on a trajectory similar to the Permian because we really don’t want to be on that trajectory,” Stanford University scientist Jonathan Payne said. “It doesn’t look like we will warm by around 10C and we haven’t lost that amount of biodiversity yet. But even getting halfway there would be something to be very concerned about. The magnitude of change we are currently experiencing is fairly large.” Curtis Deutsch, an oceanography expert at University of Washington said: “We are...
Greenhouse Gas Emissions Accelerate Like a ‘Speeding Freight Train’ in 2018

Greenhouse Gas Emissions Accelerate Like a ‘Speeding Freight Train’ in 2018

SOURCE: NYTimes DATE: December 6, 2018 SNIP: Greenhouse gas emissions worldwide are growing at an accelerating pace this year, researchers said Wednesday, putting the world on track to face some of the most severe consequences of global warming sooner than expected. Scientists described the quickening rate of carbon dioxide emissions in stark terms, comparing it to a “speeding freight train” and laying part of the blame on an unexpected surge in the appetite for oil as people around the world not only buy more cars but also drive them farther than in the past — more than offsetting any gains from the spread of electric vehicles. Worldwide, carbon emissions are expected to increase by 2.7 percent in 2018, according to the new research, which was published by the Global Carbon Project, a group of 100 scientists from more than 50 academic and research institutions and one of the few organizations to comprehensively examine global emissions numbers. Emissions rose 1.6 percent last year, the researchers said, ending a three-year plateau. The analysis found that the world is on pace to release a record 37.1 gigatons of planet-warming emissions in 2018, led in large part by China, the United States and India. Even as coal has fallen out of favor in some markets, the rise in emissions has been driven by stronger demand for natural gas and oil, scientists said. And even as the use of renewable energy like solar and wind power has expanded exponentially, it has not been enough to offset the increased use of fossil...
Policies of China, Russia and Canada threaten 5C climate change, study finds

Policies of China, Russia and Canada threaten 5C climate change, study finds

SOURCE: The Guardian DATE: November 16, 2018 SNIP: China, Russia and Canada’s current climate policies would drive the world above a catastrophic 5C of warming by the end of the century, according to a study that ranks the climate goals of different countries. The US and Australia are only slightly behind with both pushing the global temperature rise dangerously over 4C above pre-industrial levels says the paper, while even the EU, which is usually seen as a climate leader, is on course to more than double the 1.5C that scientists say is a moderately safe level of heating. The study, published on Friday in the journal Nature Communications, assesses the relationship between each nation’s ambition to cut emissions and the temperature rise that would result if the world followed their example. Among the major economies, the study shows India is leading the way with a target that is only slightly off course for 2C. Less developed countries are generally more ambitious, in part because they have fewer factories, power plants and cars, which means they have lower emissions to rein in. On the opposite side of the spectrum are the industrial powerhouse China and major energy exporters who are doing almost nothing to limit carbon dioxide emissions. These include Saudi Arabia (oil), Russia (gas) and Canada, which is drawing vast quantities of dirty oil from tar sands. Fossil fuel lobbies in these countries are so powerful that government climate pledges are very weak, setting the world on course for more than 5C of heating by the end of the century. Only slightly better are the group of countries that...
As Greenland Warms, Nature’s Seasonal Clock Is Thrown Off-Kilter

As Greenland Warms, Nature’s Seasonal Clock Is Thrown Off-Kilter

SOURCE: Yale e360 DATE: September 13, 2018 SNIP: From their perch on a rocky ridge in southwestern Greenland, graduate students Rebecca Walker and Conor Higgins peer through binoculars, looking for caribou. It’s a cool, June day and the tundra is ablaze with tiny magenta, pink, and yellow wildflowers. Crystalline lakes dot the glacially carved valleys, and from the round-topped mountains you can catch the glint of the massive Greenland Ice Sheet to the east. Below, the Watson River tumbles toward Kangerlussuaq Fjord, 12 miles to the west. It’s quiet, save for bird song, the rush of the wind, and the frequent crash of ice shearing off nearby Russell Glacier. Two decades ago, Walker and Higgins would have seen hundreds of caribou from the top of this same hill, set amid an ancestral caribou calving grounds. But these days the herds are a fraction of their former size, and Walker and Higgins spot only a handful of females and two calves a mile away. The ecologist supervising the students — Eric Post of the University of California, Davis — says the decline is very likely linked to a rapidly warming climate that is driving the schedules of caribou and the tundra plants they eat seriously out of balance. Post first came to the area 25 years ago to study calving in large herds of caribou. But around the early 2000s, he began noticing a major change. “As it got warmer and warmer and the growth season started earlier and earlier, the caribou calving season wasn’t starting earlier to the same extent,” Post says. The advancing plant growth was being triggered...
Hot nights: Summer low temperatures were warmest on record in Lower 48

Hot nights: Summer low temperatures were warmest on record in Lower 48

SOURCE: Washington Post DATE: September 6, 2018 SNIP: Americans seeking to cool off after long, hot days this summer found little relief in the dark of night. Windows were shut, and air-conditioners kept humming as low temperatures averaged over the nation were the warmest in over 120 years of records. In its latest climate report, the National Oceanic and Atmospheric Administration (NOAA) announced the hot nights pushed the average summer temperature to its fourth-warmest level on record, tied with 1934. The average high temperature ranked 11th warmest in records that date back to 1895, but the average low was a record-warm, 2.5 degrees above average, and 0.1 degrees above the previous record in 2016. As greenhouse gas concentrations in the atmosphere keep increasing, overnight low temperatures are warming “nearly twice as fast as afternoon high temperatures,” according to NOAA. “[T]he 10 warmest summer minimum temperatures have all occurred since 2002,” NOAA wrote. Such warm nights have important consequences. They increase heat stress on the homeless and those without air conditioning, which can lead to heat-related illness and death. At the same time, they require increased use of air-conditioning for those with access, which adds more heat-trapping gases into the...