Bjørn Lomborg: ‘Climate policies can end up costing more than 11% of world’s GDP’ – ‘We ought never to have entertained the notion that the world’s greatest challenge could be to reduce temperature rises in our generation by a fraction of a degree’
New Study by Dr. Indur Goklany: ‘Global Warming Policies Might Be Bad for Your Health’ – ‘Issues of poverty like malnutrition and unsafe water have a global impact of death and disease 70 times larger than that of theoretical climate change’
‘The hilarious history of ‘climate tipping points’ – ‘Marc Morano at Climate Depot debunks the fake hysteria’ – ‘Saturday Night Live ought to be parodying’
Sea Ice Update April 20 2014 – Global Sea Ice 1.05 million sq km Above Normal – Antarctic Sea Ice 42nd Daily Record
Columnist on IPCC: ‘Like all UN reports, it should be treated with the same kind of skepticism and contempt that greets every utterance that is farted out of the bowels of that corrupt, counterproductive, bloated and profoundly dangerous organisation’
Consensus Busting report: ‘The human impact on global climate is small; and any warming that may occur as a result of anthropogenic CO2 and other greenhouse gas emissions is likely to have little effect on either Earth’s climate or biosphere’
Nature Geoscience. doi:10.1038/ngeo2148
Author: Erich M. Fischer
Record-breaking heatwaves in 2003 and 2010 surprised both the public and experts. Observations provide new insights into how temperatures escalated to unprecedented values through the interaction of boundary-layer dynamics and land surface drying.
Nature Geoscience. doi:10.1038/ngeo2152
Author: Craig E. Manning
Carbon loss from subducting slabs is thought to be insufficient to balance carbon dioxide emissions at arc volcanoes. Analyses of ancient subducted rocks in Greece suggest that fluid dissolution of slab carbonate can help solve this carbon-cycle conundrum.
Nature Geoscience. doi:10.1038/ngeo2143
Authors: Jay J. Ague & Stefan Nicolescu
The balance between the subduction of carbonate mineral-bearing rocks into Earth’s mantle and the return of CO2 to the atmosphere by volcanic and metamorphic degassing is critical to the carbon cycle. Carbon is thought to be released from subducted rocks mostly by simple devolatilization reactions. However, these reactions will also retain large amounts of carbon within the subducting slab and have difficulty in accounting for the mass of CO2 emitted from volcanic arcs. Carbon release may therefore occur via fluid-induced dissolution of calcium carbonate. Here we use carbonate δ18O and δ13C systematics, combined with analyses of rock and fluid inclusion mineralogy and geochemistry, to investigate the alteration of the exhumed Eocene Cycladic subduction complex on the Syros and Tinos islands, Greece. We find that in marble rocks adjacent to two fluid conduits that were active during subduction, the abundance of calcium carbonate drastically decreases approaching the conduits, whereas silicate minerals increase. Up to 60–90% of the CO2 was released from the rocks—far greater than expected via simple devolatilization reactions. The δ18O of the carbonate minerals is 5–10 lighter than is typical for metamorphosed carbonate rocks, implying that isotopically light oxygen was transported by fluid infiltration from the surroundings. We suggest that fluid-mediated carbonate mineral removal, accompanied by silicate mineral precipitation, provides a mechanism for the release of enormous amounts of CO2 from subduction zones.
Nature Geoscience. doi:10.1038/ngeo2141
Authors: Diego G. Miralles, Adriaan J. Teuling, Chiel C. van Heerwaarden & Jordi Vilà-Guerau de Arellano
The recent European mega-heatwaves of 2003 and 2010 broke temperature records across Europe. Although events of this magnitude were unprecedented from a historical perspective, they are expected to become common by the end of the century. However, our understanding of extreme heatwave events is limited and their representation in climate models remains imperfect. Here we investigate the physical processes underlying recent mega-heatwaves using satellite and balloon measurements of land and atmospheric conditions from the summers of 2003 in France and 2010 in Russia, in combination with a soil–water–atmosphere model. We find that, in both events, persistent atmospheric pressure patterns induced land–atmosphere feedbacks that led to extreme temperatures. During daytime, heat was supplied by large-scale horizontal advection, warming of an increasingly desiccated land surface and enhanced entrainment of warm air into the atmospheric boundary layer. Overnight, the heat generated during the day was preserved in an anomalous kilometres-deep atmospheric layer located several hundred metres above the surface, available to re-enter the atmospheric boundary layer during the next diurnal cycle. This resulted in a progressive accumulation of heat over several days, which enhanced soil desiccation and led to further escalation in air temperatures. Our findings suggest that the extreme temperatures in mega-heatwaves can be explained by the combined multi-day memory of the land surface and the atmospheric boundary layer.
Nature Geoscience. doi:10.1038/ngeo2142
Authors: Jeffrey A. Nittrouer & Enrica Viparelli
The Mississippi River delta is undergoing a catastrophic drowning, whereby 5,000 km2 of low-lying wetlands have converted to open water over at least the past eight decades, as a result of many anthropogenic and natural factors. Continued net land loss has been thought inevitable due to a decline in the load of total suspended sediment—both sand and mud—carried by the river. However, sand—which accounts for 50–70% of modern and ancient Mississippi delta deposits but comprises only 20% of the sampled portion of the total load—could be more important than mud for subaerial delta growth. Historically, half of the Mississippi River sediment load is supplied by the Missouri River. Here we analyse suspended sediment load data from two locations downstream from the lowest Missouri River dam to show that the measured sand load in the lower 1,100 km of the Mississippi River has not significantly diminished since dam construction. A one-dimensional numerical model of river morphodynamics predicts that the sand load feeding the delta will decrease only gradually over the next several centuries, with an estimated decline from current values of no more than about 17% within the coming six centuries. We conclude that the lower Mississippi River channel holds a significant reservoir of sand that is available to replenish diminished loads via bed scour and substantially mitigate land loss.
Nature Geoscience. doi:10.1038/ngeo2164
Authors: J. García-Serrano & C. Frankignoul