May 16th, 2010 by Joshua S Hill
A new study looks specifically at the benefits and tradeoffs that the planet’s forests play in the global carbon cycle.
[social_buttons]Published in the spring edition of Issues in Ecology, the study authored by Mike Ryan from the United States Department of Agriculture, Forest Service and colleagues looked at how the carbon offsets provided by forests and harvested woods can increase, and what the tradeoffs will be.
“Several strategies for offsetting carbon emissions have been proposed or are currently being implemented in the U.S.,” says Ryan, lead author of the paper. “Some of the important tradeoffs are worth mentioning because many people have viewed forests as a simple and uncomplicated partial solution to reducing CO2 in the atmosphere, and they are not.”
Ryan and colleagues looked at eight separate strategies currently in effect or proposed in the United States, their risks, uncertainties and the individual tradeoffs: avoiding deforestation, afforestation (planting or replanting forests), decreasing harvests, increasing the growth rate of existing forests, using biomass energy from forests to reduce carbon emissions, using wood products in place of concrete or steel for building materials, implementing urban forestry and using fuel management to reduce fire threats.
But each of these steps forward need to be taken understanding that there will be tradeoffs in doing so. For example, a wholesale reduction in harvesting, avoiding deforestation or planting entire new forests could very well increase the amount of carbon stored within forests in the US. However there are implications for doing so.
For example, the demand for forest products will not simply disappear overnight just because the government decides to stop harvesting forests.
“The numbers are daunting because our fossil fuel use is so large,” says Ryan adding another example to the pile. “Take increasing the use of wood for biomass energy: In order to offset just 10 percent of our fossil fuel use, we would need to harvest all of the annual forest production of U.S. forests. This practice also would lower the long term effects of carbon stored in forests.”
“To offset another 10 percent of our fossil fuel use with tree planting would require planting trees on one-third of our agricultural land,” adds co-author Robert B. Jackson from Duke University.
On top of the tradeoffs that will have to be negotiated, and the issues with pushing forward cost ineffective measures, are the results of our increasing carbon. The climate change that we are hoping to negate by increasing the carbon in our forests could in fact increase the fires, storms and insect outbreaks which all decrease the amount of carbon stored in the forests.
“So, we need to make sure we focus on retaining the forests we have by making sure we get tree regeneration after these disturbances,” says Ryan.
“This topic could not be more relevant,” says Jill Baron, Editor-in-Chief of Issues in Ecology. “The need for biological carbon storage is ever apparent, but the methods for making the most of our forest stores while not reducing other important forest ecosystem services are still underexplored. This paper, like future Issues in Ecology, provides a synthesis of the current scientific research and understanding on the topic. It should be on the desk of anyone interested in how to minimize the effects of climate change, and certainly anyone assigned with mitigating climate change through forest carbon storage.”
Source: Ecological Society of America
Image Source: Horia Varlan
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