Short and sweet — does exactly what it says on the can. Reputed to be directed by the Coen brothers.
While much of the alarm over global deforestation centres on the Amazon rainforest, which continues at a shocking rate, African rainforests receive relatively little attention. Yet a study published today in Nature demonstrates the increasing size of the carbon sink these forests contain: similar to Amazonian forests in per unit area terms.
A large international team of scientists, headed up by Simon Lewis at the University of Leeds, found that across 79 plots in ten African countries, the above-ground carbon storage increased by 0.63 Mg C per hectare per year, between 1968 and 2007. Scaling up to include unmeasured material — roots, small trees, rotting trees and so on — brings the continental increase in carbon storage to 0.34 Pg C (that’s 340 million tonnes of carbon) per year. Read the rest of this entry »
We’ve alluded to the idea that “food miles” need to be treated with caution elsewhere. Here’s another example: the Co-operative Group’s annual sustainability report contains details of a “life-cycle” analysis (LCA) of the amount of embedded carbon in a humble 400g punnet of strawberries.
The domestic “Ava” offering, grown at Blairgowrie farm in Scotland, contains 850g of carbon. The alternative “Sabrosa” strawberries, from Spain, contain only 600g of carbon. If you’re basing your purchase decision solely on global warming impact you should buy the Spanish version. Read the rest of this entry »
Carbon sequestration — taking CO2 out of the atmosphere, as opposed to merely not adding to it — is the thing that will fix the mess we’ve created. Avoiding emissions is all well and good, and will ensure that things get back to how they should be, eventually. But wouldn’t it be a good idea to help things along a little?
There have been lots of suggestions about how we might be able to draw CO2 back out of the sky. Solutions range from the mechanical (e.g. the fabled carbon capture and storage beloved of coal-firing power companies), through the chemical (like iron enrichment of the oceans to promote blooming of carbon-storing algae) to the biological (such as our favourite, planting trees). Read the rest of this entry »
Old growth forest on the western United States is dying back at an increasing rate, accoring to a study published this week in Science magazine. The study, led by USGS biologist Phil van Mantgem, found that background mortality rates — those not directly attributable to some catastrophic effect, such as fire — have risen rapidly in recent decades.
The study, which used census data from 67 long-term plots located in ancient forests (average age 450 years, some sites in excess of 1000 years), found that mortality rates had increased at the vast majority of sites, whereas recruitment rates — replacement of dead trees with new ones — had neither increased or decreased over the same period.
The dieback couldn’t be pinned down to any local effects, such as pollution, local competition or fire prevention measures. Instead, say the study’s authors, regional warming and the ensuing water problems it brings — faster snowmelt leading to longer summer drought — are putting the strain on the trees. Read the rest of this entry »