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Posts Tagged ‘carbon-capture’

Economic Value of an Urban Forest: $80 billion

Posted in Models, Research, Tools by Kate Archdeacon on March 22nd, 2012


Photo by Mike_tn via flickr CC

From “Environmental contribution of Tennessee’s urban trees: $80 billion”  by James Holloway:

A study published by the US Forest service values the State of Tennessee’s urban forest at $80 billion thanks to its contributions to the environment. With an urban population of 284 million, that equates to a mean value of $282 per tree.

The total is based on a number of costs that are to some extent offset by the presence of Tennessee’s urban forest (its urban tree population, in other words). These include $350 million-worth of carbon storage based on the current standing stock, over $204 million every year in pollution removal, $18.4 million per year in additional carbon sequestration, and $66 million per year in energy savings-“the most significant contribution” made by the urban forest, according to State Forester Steven G. Scott. But how are the environmental benefits of the trees evaluated?

Data was collected and analyzed using the Forest Service’s own i-Tree Eco software. Using a mobile app providing strict protocols for data collection, researchers took information from 2418 trees and saplings across 255 field plots. Variables noted include species, diameter at breast height (or DBH—taken at 1.4 meters above ground), height, crown dimensions, foliage transparency, damage, and proximity to buildings. The pool of sample data is assumed to be representative of the total population, and from there the software crunches the numbers using “peer-reviewed equations” to paint a macro-scale picture of the urban forest, based on quantifiable characteristics that describe its structure, condition and function.

>>Read the full article by James Holloway on Ars Technica.
>>Read the US Forest Service study.


Nature, Science and Livelihood: effective carbon capture & storage

Posted in Research by Kate Archdeacon on November 2nd, 2009

Source: The Ecologist, from the article  “Forests and oceans more effective than carbon capture technology”, Oct 14

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Image: brentbat via flickr CC

Two new reports say existing forest and ocean systems offer the most cost effective way to capture and store carbon – far cheaper than industrial Carbon Capture and Storage (CCS) technology.

Forests:

Research led by University of Michigan has shown that there is more potential than we realise for forests to act as carbon ‘sinks’. The study looked at 80 forests in the developing world over 15 years and found that local ownership rather than government control of the land was the best guarantee against misuse. The research suggested this is because local communities were dependent on the forests for their livelihoods, and so valued its preservation more highly.  ‘The urgency of the global need to increase carbon storage in forests and local reliance on forests for continuing livelihood benefits through extraction of forest biomass make it especially important that scientists better understand the relationship between carbon storage in forests and their contributions to livelihoods,’ said lead author Professor Arun Agrawal. ‘We show that larger forest size and greater rule-making autonomy at the local level are associated with high carbon storage and livelihood benefits,’ he said.

Marine Systems:

In a separate development, a report by the United Nations Environment Programme (UNEP) has estimated that marine ecosystems are storing carbon equal to half the annual emissions of the global transport sector. It says that 55 per cent of the biological carbon captured in the world is removed from the atmosphere by marine organisms, producing so-called ‘blue carbon’. Unlike carbon capture and storage on land, where carbon may be locked away only for decades or centuries, that stored in the oceans remains for millennia. ‘We already know that marine ecosystems are multi-trillion dollar assets linked to sectors such as tourism, coastal defense, fisheries and water purification services: now it is emerging that they are natural allies against climate change,’ said Achim Steiner, UN Under-Secretary General and UNEP Executive Director. ‘Indeed this report estimates that halting losses and catalysing the recovery of marine ecosystems might contribute to offsetting up to seven percent of current fossil fuel emissions and at a fraction of the costs of technologies to capture and store carbon at power stations,’ he added.

Kate says: Unfortunately, this is not necessarily all good news… Check out this article in the Guardian on how carbon absorption is raising ocean acidity to corrosive levels.