Volume 2 Issue 12, December 2009

The fact that cumulative carbon dioxide emissions are more important than annual emission rates calls for a fresh approach to climate change mitigation. One option would be a mandatory link between carbon sequestration and fossil fuel extraction.

Storage of the carbon dioxide that is produced by burning fossil fuels is one way to avoid the damaging consequences of climate change. A range of observations suggests that geological carbon storage is much less risky than unabated carbon emissions to the atmosphere.

The conversion of coal into liquid fuel is one of the dirtiest ways to produce transportation fuel. But if carbon is captured and stored, and some biomass is added, it could become the cleanest way to power jets, trucks and trains.

The path towards mitigating global warming is going to be tortuous. Capturing carbon dioxide and pumping it directly into the deep ocean to avoid atmospheric build-up is an option that has been dismissed prematurely.

Volcanic rocks on the sea floor are home to diverse and abundant microbial communities. Microscopic and spectroscopic analyses suggest that iron and manganese derived from hydrothermal venting support microbial colonization of the ocean crust.

In a warming climate, large lakes experience increasing water temperatures and ice loss. Observations from Lake Superior show that regional temperature rise has led to an increase in wind speeds over the lake.

Processes and triggers of deformation in big, slow-moving landslides are often unclear. The Slumgullion slide seems to stick and slip in tune with atmospheric tides.

Efforts to control climate change require the stabilization of atmospheric carbon dioxide concentrations. An assessment of the trends in sources and sinks of atmospheric carbon dioxide suggests that the sinks are not keeping up with the increase in carbon dioxide emissions, but uncertainties are still large.

The rapid increase in anthropogenic emissions of greenhouse gases necessitates the consideration of mechanisms for capturing and storing carbon dioxide. Recent work suggests that fluid or gaseous carbon dioxide can be injected into the Earth's crust, and locked up as carbonate minerals to achieve near-permanent and secure sequestration.

Carbon dioxide uptake by the terrestrial biosphere has the potential to mitigate fossil fuel emissions. Comprehensive estimates of Europe's greenhouse-gas balance suggest that any uptake of carbon dioxide by the terrestrial biosphere is offset by methane and nitrous oxide emissions.

A set of lakes filled with liquid hydrocarbon have been discovered in the high latitudes of Saturn’s moon Titan. A quantification of these lakes shows a dramatic hemispheric asymmetry in their occurrence, which could be a result of the orbital configurations of Titan and Saturn.

Surface water temperatures in Lake Superior have warmed faster than air temperature during the thermally stratified summer season. Analyses of a range of observations show that as a result surface wind speeds above the lake have been increasing by nearly 5% per decade.

Accurate quantification of Antarctic ice-sheet mass balance and its contribution to global sea-level rise remains challenging. Gravity Recovery and Climate Experiment data spanning the period April 2002 to January 2009 confirm earlier estimates of ice loss for Antarctica and indicate that East Antarctica started losing mass in about 2006.

The Slumgullion landslide in the western United States has been moving almost continuously for over 100 years. Observations and numerical modelling show that air pressure changes from atmospheric tides trigger daily movement.

Oceanic nitrogen concentrations are controlled by the balance between nitrogen fixation and denitrification. Examination of nutrient concentrations in the North and South Atlantic Ocean suggests that nitrogen fixation is controlled by the supply of dissolved iron.

Exposed rocks on underwater mountains and ridges host abundant and diverse microbial communities. X-ray and microscopic analyses of volcanic rocks associated with Loihi seamount in Hawaii suggest that seafloor microbes may commonly be sustained by energy inputs from the water column.

A significant number of the early aftershocks following large shallow earthquakes are missing in existing earthquake catalogues. An analysis of the waveforms of 3,647 relocated earthquakes along the Parkfield section of the San Andreas fault reveals 11 times more aftershocks within three days of the 2004 Parkfield earthquake than listed in a standard catalogue.

Earthquakes are far more common along the San Jacinto fault in California than the nearby southern San Andreas fault. An analysis of seismic and geodetic data suggests that the excess seismicity along the San Jacinto fault is due to a creeping motion along the deeper parts of the fault.

Zircon is a common mineral in continental crustal rocks, and is often used in the reconstruction of geological processes. Analyses of the isotopic and trace element compositions of large zircons of gem quality from the Bohemian Massif reveal that zircons can remain intact in the upper mantle under specific chemical conditions for about 20–60 million years.

Geochemical analyses and climate modelling suggest that 2.5 billion years ago much of the nitrogen now stored in the solid Earth was in the atmosphere, and that the higher atmospheric nitrogen levels would have increased the efficacy of greenhouse gases, thus warming the Earth.

As the world's leaders are getting ready to negotiate a new climate treaty in Copenhagen, there is No. sign of a long-term reduction in human-made carbon dioxide emissions. As a result, carbon sequestration may turn out to be our only option for controlling climate change. In this focus we collect articles that cover emissions budgets of carbon dioxide and other greenhouse gases and options for sequestration, as well as commenting on the difficult choices we are going to face in combating climate change.