Decade-long study says trees may not be good at offsetting carbon

Step away from the vegetation, treehuggers, and find something else to embrace. New research finds that when it comes to offsetting greenhouse gases, trees may not be up to the challenge. For 10 years, Duke University researchers plied a stand of North Carolina loblolly pines with higher-than-normal levels of carbon dioxide; they found that the foliaged friends grew more than non-gassed trees, but did not consistently absorb significantly higher levels of CO2. “The responses are very variable according to how available other resources are — nutrients and water — that are necessary for tree growth,” says researcher Heather McCarthy. “It’s really not anywhere near the magnitude that we would really need to offset emissions.” For tree planting to have a discernible offsetting effect under the conditions they tested, the amount of fertilizer required would impact groundwater quality at a level “intolerable to society,” says project director Ram Oren. Sigh. Ocean-hugging, anyone?