6 February 2018, Climate News Network, Ozone layer recovery falters unexpectedly. The Earth’s protective ozone layer is not recovering uniformly from the damage caused to it by industry and other human activities. And scientists are not sure why it isn’t. An international research team says the ozone, which protects humans and other species from harmful ultraviolet radiation, is continuing to recover at the poles. But recovery at lower latitudes, where far more people live, is not. The layer has been declining since the 1970s because of the effect of man-made chemicals, chiefly chlorofluorocarbons (CFCs) and similar gases, used mainly in refrigerants and aerosols. There is a link between the CFCs and global warming, though they are different and neither is the main cause of the other. Some suggested CFC replacements themselves proved to be powerful greenhouse gases. CFCs and the other gases were banned under an international agreement, the Montreal Protocol, and since then parts of the layer have been recovering, particularly at the poles. But the latest research, published in the journal Atmospheric Chemistry and Physics, finds that the bottom part of the ozone layer at more populated latitudes is not recovering, for reasons so far unidentified. Read More here
Category Archives: The Science
12 January 2018, Reuters, Warming set to breach Paris accord’s toughest limit by mid century: draft. Global warming is on track to breach the toughest limit set in the Paris climate agreement by the middle of this century unless governments make unprecedented economic shifts from fossil fuels, a draft U.N. report said. The draft, of a report due for publication in October, said governments will also have to start sucking carbon dioxide from the air to achieve the ambition of limiting temperatures to 1.5 degrees Celsius (2.7 Fahrenheit) above pre-industrial times. “There is very high risk that … global warming will exceed 1.5 degrees Celsius above pre-industrial levels,” the U.N. panel of experts wrote, based on the current pace of warming and current national plans to limit their greenhouse gas emissions. There were no historic precedents for the scale of changes required in energy use, to shift from fossil fuels to renewable energies, and in reforms ranging from agriculture to industry to stay below the 1.5C limit, it said. The draft, by the U.N.’s Intergovernmental Panel on Climate Change (IPCC) of leading scientists and obtained by Reuters, says average surface temperatures are about 1C above pre-industrial times and that average temperatures are on track to reach 1.5C by the 2040s. Curbing warming to 1.5C would help limit heat extremes, droughts and floods, more migration of people and even risks of conflict compared to higher rates of warming, according to the draft summary for policymakers. But a 1.5C rise might not be enough to protect many coral reefs, already suffering from higher ocean temperatures, and ice stored in Greenland and West Antarctica whose melt is raising sea levels. Read More here. For expert response read more here
11 January 2018, Yale Climate Connections, Bomb-cyclone’ weather in a warming world. This month’s Yale Climate Connections ‘This is not Cool’ video offers a plain-English science-based response to the inevitable ‘So much for climate change’ weather riddle. With New England, much of the middle Atlantic region, and parts of the southeast extending well into Florida suffering through late December-, early January-punishing cold temperatures, and in a number of places, record night-time lows and heavy snowfalls – the inevitable “so much for global warming” argument seemed certain to arise. On the one hand there were analytical news stories such as The Washington Post’s Capital Weather Gang’s story headlined “Historic ‘bomb cyclone’ unleashes blizzard conditions from coastal Virginia to New England. Frigid air to follow.” There also was President Trump’s “we could use a little more of that good old global warming” tweet from his “balmy Mar a Lago” residence looking forward to a frigidly cold New Years Eve dropping of the 2018 ball at Times Square in New York City. So how then to explain such not-at-all-unusual experience of cold weather temperatures even as the global temperatures continue rising? (One can safely anticipate having to explain cool summer-time daily temperatures in some places as the world continues warming.) To some extent, it’s a simple question of needing to repeatedly explain the difference between weather (short term and local) and climate (long term and global). Read More here
11 January 2018, The Conversation, Explainer: ‘bomb cyclones’ – the intense winter storms that hit the US (and Australia too). The eastern United States experienced a very severe winter storm last week, which caused damaging winds, heavy snow and the highest tide on record for Boston. Meteorologists call this type of storm a “bomb cyclone”, or simply a “bomb”. But what is it? A “bomb” is an old meteorological term for a low-pressure system outside the tropics (that is, an extratropical cyclone) that intensifies very rapidly, based on how fast the atmospheric pressure drops at the centre of the storm. A common benchmark is a drop of 24 hectopascals (hPa) over 24 hours, although this varies slightly with latitude. The recent bomb in the US had a reported pressure drop of 59hPa over 24 hours, making it one of the strongest such storms ever recorded. Read More here