Category Archives: Impacts Observed & Projected

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13 February 2018, NASA Goddard Institute, The rate of global sea level rise has been accelerating in recent decades, rather than increasing steadily, according to a new study based on 25 years of NASA and European satellite data. This acceleration, driven … Continue reading →

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30 January 2018, The Conversation, Climate scientists explore hidden ocean beneath Antarctica’s largest ice shelf. Antarctica’s Ross Ice Shelf is the world’s largest floating slab of ice: it’s about the size of Spain, and nearly a kilometre thick. The ocean beneath, roughly the volume of the North Sea, is one of the most important but least understood parts of the climate system. We are part of the multi-disciplinary Aotearoa New Zealand Ross Ice Shelf programme team, and have melted a hole through hundreds of metres of ice to explore this ocean and the ice shelf’s vulnerability to climate change. Our measurements show that this hidden ocean is warming and freshening – but in ways we weren’t expecting. A hidden conveyor belt  All major ice shelves are found around the coast of Antarctica. These massive pieces of ice hold back the land-locked ice sheets that, if freed to melt into the ocean, would raise sea levels and change the face of our world. An ice shelf is a massive lid of ice that forms when glaciers flow off the land and merge as they float out over the coastal ocean. Shelves lose ice by either breaking off icebergs or by melting from below. We can see big icebergs from satellites – it is the melting that is hidden. Because the water flowing underneath the Ross Ice Shelf is cold (minus 1.9C), it is called a “cold cavity”. If it warms, the future of the shelf and the ice upstream could change dramatically. Yet this hidden ocean is excluded from all present models of future climate. All major ice shelves are found around the coast of Antarctica. These massive pieces of ice hold back the land-locked ice sheets that, if freed to melt into the ocean, would raise sea levels and change the face of our world. An ice shelf is a massive lid of ice that forms when glaciers flow off the land and merge as they float out over the coastal ocean. Shelves lose ice by either breaking off icebergs or by melting from below. We can see big icebergs from satellites – it is the melting that is hidden. Because the water flowing underneath the Ross Ice Shelf is cold (minus 1.9C), it is called a “cold cavity”. If it warms, the future of the shelf and the ice upstream could change dramatically. Yet this hidden ocean is excluded from all present models of future climate. Read More here

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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

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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