New paper rules out volcanoes as the cause of the ‘pause’ – Published in Atmospheric Science Letters

The impact of volcanic eruptions in the period 2000–2013 on global mean temperature trends evaluated in the HadGEM2-ES climate model

Jim M. Haywood, Andy Jones, Gareth S. Jones

The slow-down in global warming over the last decade has lead to significant debate about whether the causes are of natural or anthropogenic origin. Using an ensemble of HadGEM2-ES coupled climate model simulations we investigate the impact of overlooked modest volcanic eruptions. We deduce a global mean cooling of around −0.02 to −0.03 K over the period 2008–2012. Thus while these eruptions do cause a cooling of the Earth and may therefore contribute to the slow-down in global warming, they do not appear to be the sole or primary cause.

New paper finds Greenland melt ‘strongly influenced’ by natural geothermal heating

New paper finds Greenland melt ‘strongly influenced’ by natural geothermal heating

http://hockeyschtick.blogspot.com/2013/08/new-paper-finds-greenland-melt-strongly.html

Greenland ice sheet IS melting but much of the heating is coming from INSIDE the earth

Study suggests melting in an area is due to composition of Earth’s mantle 

The IceGeoHeat team claims they produced more accurate forecasts by adding their new findings to earlier models on climate change

By ELLIE ZOLFAGHARIFARD The Daily Mail

PUBLISHED: 08:04 EST, 12 August 2013 | UPDATED: 08:25 EST, 12 August 2013

Ice in Greenland is melting partly because of heat from the Earth’s mantle, according to a team of international researchers.

The group claims that they are the first to find a connection between melting of the Greenland ice sheet and the high heat flow from the Earth’s mantle.

The findings, they suggest, could have implications for future predictions on climate change and the reasons behind ice melt in the region.

The Greenland ice sheet is often considered an important contributor to future global sea-level rise over the next century or longer.

In total, it contains an amount of ice that would lead to a rise of global sea level by more than seven metres, if completely melted.

The ice loss from the ice sheet has been increasing over the last decade, with half of it attributed to changes in surface conditions with the remainder due to increased iceberg calving – the process by which ice detaches from the glacier to become an iceberg.

The international research initiative IceGeoHeat, led by the GFZ German Research Centre for Geosciences, said that the effect of the Earth’s crust and upper mantle in current climate modelling are too simplistic.

They modelled the Earth’s mantle against the ice sheet and found that melting occurs in a given area due to the composition of the mantle underneath it.

Writing in the current online issue of Nature Geoscience, the group argues that this effect cannot be neglected when putting together data on climate change.

The Greenland ice sheet loses about 227 gigatonnes of ice per year and contributes about 0.7 millimeters to the currently observed mean sea level change of about 3 mm per year.

The team point out, however, that existing model calculations were based on a consideration of the ice cap. 

GFZ scientists Alexey Petrunin and Irina Rogozhina have now combined earlier ice and climate models with their new thermo-mechanical model for the Greenland lithosphere. …