Climate Science

Early in his career, a scientist named Mario J. Molina was pulled into seemingly obscure research about strange chemicals being spewed into the atmosphere. Within a year, he had helped discover a global environmental emergency, work that would ultimately win a Nobel Prize.

Now, at 70, Dr. Molina is trying to awaken the public to an even bigger risk. He spearheaded a committee of the American Association for the Advancement of Science, the world’s largest general scientific society, which released a stark report Tuesday on global warming.

Nate Silver’s highly anticipated data-driven news site FiveThirtyEight launched on Monday, with a controversial figure covering science issues. Silver has brought on Roger Pielke, Jr., a professor of environmental studies at the University of Colorado Boulder, as a contributing writer – a political scientist who comes with a long history of data distortion and confrontations with climate scientists.

In a rare intervention into a policy debate, the American Association for the Advancement of Science urged Americans to act swiftly to reduce greenhouse gas emissions – and lower the risks of leaving a climate catastrophe for future generations. “As scientists, it is not our role to tell people what they should do,” the AAAS said in a new report, What we know.

Climate-change skeptics -- and everyone else in Canada -- had better bundle up. Research shows extended cold snaps like we’ve seen this winter could be a direct result of climate change. In a Rutgers University paper published last year, researchers Jennifer Francis and Stephen Vavrus wrote that the melting of Arctic ice was weakening the jet stream, the band of fast-moving wind that separates colder northern air from warmer air further south. As it weakens, it dips southward for longer periods than in the past, bringing icy-cold air with it for increasingly long stays.

Between 1998 and 2013, the Earth’s surface temperature rose at a rate of 0.04°C a decade, far slower than the 0.18°C increase in the 1990s. Meanwhile, emissions of carbon dioxide (which would be expected to push temperatures up) rose uninterruptedly. This pause in warming has raised doubts in the public mind about climate change. A few sceptics say flatly that global warming has stopped. Others argue that scientists’ understanding of the climate is so flawed that their judgments about it cannot be accepted with any confidence.

Last Friday, the White House posted on its website a six-page criticism of me by the president’s science advisor, John Holdren, expanding on testimony he had given to Congress last week claiming that my views on climate change and extreme weather are outside of "mainstream scientific opinion.” Holdren was specifically responding to Se

Large-scale human engineering of the Earth's climate to prevent catastrophic global warming would not only be ineffective but would have severe unintended side effects and could not be safely stopped, a comparison of five proposed methods has concluded.

Because the pool of climate experts who dispute that humans are the primary cause of global warming is so small, representing just 2 to 4 percent of climate scientists, climate contrarians often reference the same few contrarian scientists.

What’s the difference between a majestic layer of white sea ice and an ominous dark blue open ocean? For the Arctic, it means about a 30 to 50 per cent loss in reflectivity (or albedo). And when seasonal sea-ice states are between 30 and 80 per cent below 1979 measures (depending on the method used to gauge remaining sea ice and relative time of year), that means very, very concerning additional heating impacts to an already dangerous human-caused warming. How concerning, however, remained somewhat unclear until recently.

When Elizabeth Kolbert joined The New Yorker in 1999, after more than a decade covering New York politics as a reporter and columnist for The New York Times, she began gravitating to environmental issues. “The magazine has a history in this area,” she told me in one of two recent conversations. “They’d published Rachel Carson. It was unoccupied territory at the time.” This week Ms.