Pecologix Political Ecology Blotter

An important source of uncertainty in anticipating the effects of climate change on agriculture is limited understanding of crop responses to extremely high temperatures1, 2. This uncertainty partly reflects the relative lack of observations of crop behaviour in farmers’ fields under extreme heat. We used nine years of satellite measurements of wheat growth in northern [...]

Cyanobacteria are the Earth’s oldest (∼3.5 bya) oxygen evolving organisms, and they have had major impacts on shaping our modern-day biosphere. Conversely, biospheric environmental perturbations, including nutrient enrichment and climatic changes (e.g. global warming, hydrologic changes, increased frequencies and intensities of tropical cyclones, more intense and persistent droughts), strongly affect cyanobacterial growth and bloom potentials in [...]

The first plants to colonize land didn’t merely supply a dash of green to a drab landscape. They dramatically accelerated the natural breakdown of exposed rocks, according to a new study, drawing so much planet-warming carbon dioxide (CO2) from the atmosphere that they sent Earth’s climate spiraling into a major ice age. DOI: http://dx.doi.org/10.1038/ngeo1390

Ocean acidification (OA) is a reduction in oceanic pH due to increased absorption of anthropogenically produced CO2. This change alters the seawater concentrations of inorganic carbon species that are utilized by macroalgae for photosynthesis and calcification: CO2 and HCO3− increase; CO32− decreases. Two common methods of experimentally reducing seawater pH differentially alter other aspects of [...]

High precision measurements of Δ14C were conducted for monthly samples of CO2 from seven global stations over 2- to 16-year periods ending in 2007. Mean Δ14C over 2005–07 in the Northern Hemisphere was 5 ‰ lower than Δ14C in the Southern Hemisphere, similar to recent observations from I. Levin. This is a significant shift from [...]

A recent study of the net land carbon sink estimated using the Mauna Loa, Hawaii atmospheric CO2 record, fossil fuel estimates, and a suite of ocean models suggests that the mean of the net land carbon uptake remained approximately constant for three decades and increased after 1988/1989. Due to the large variability in the net [...]

How much and why precipitation changes as the climate warms is uncertain, even for the global mean. In the 21st Century of the IPCC AR4 A1b forcing scenario, global-mean precipitation increase per degree warming varies among models by over a factor of three. Clear-sky atmospheric shortwave absorption change explains over half of the intermodel spread [...]