美國(guó)一項(xiàng)最新研究成果說(shuō)，如果將種植其他農(nóng)作物的耕地改種甘蔗,，可有效降低當(dāng)?shù)貧鉁?，減緩氣候變化。
美國(guó)卡內(nèi)基學(xué)院研究人員17日在英國(guó)《自然》出版集團(tuán)新刊物《自然·氣候變化》網(wǎng)絡(luò)版報(bào)告說(shuō)，他們以甘蔗種植大國(guó)巴西約190萬(wàn)平方公里的土地作為研究對(duì)象,，通過(guò)衛(wèi)星圖像分析與溫度變化有關(guān)的一系列數(shù)據(jù),，包括氣溫、植物對(duì)陽(yáng)光反照率以及土壤和植物的水分蒸騰損失總量等,。
分析結(jié)果顯示,，如果在原來(lái)生長(zhǎng)自然植物的土地上改種農(nóng)作物或牧草，當(dāng)?shù)貧鉁仄骄鶗?huì)升高1．55攝氏度,；但如果再將農(nóng)作物或牧草改為甘蔗,，當(dāng)?shù)貧鉁仄骄鶗?huì)降低0．93攝氏度。
研究人員解釋說(shuō),，甘蔗對(duì)陽(yáng)光的反照率較高,，并且可以向周?chē)h(huán)境釋放水蒸氣,，因此具有“降溫”作用,。但他們同時(shí)強(qiáng)調(diào)，甘蔗的“降溫”作用只是相對(duì)于農(nóng)作物和牧草而言,，與自然植物相比,，它是遠(yuǎn)不能及的。（生物谷Bioon.com）
生物谷推薦原文出處：
Nature Climate Change doi:10.1038/nclimate1067
Direct impacts on local climate of sugar-cane expansion in Brazil
Scott R. Loarie,1 David B. Lobell,2 Gregory P. Asner,1 Qiaozhen Mu3 & Christopher B. Field1
The increasing global demand for biofuels will require conversion of conventional agricultural or natural ecosystems. Expanding biofuel production into areas now used for agriculture reduces the need to clear natural ecosystems, leading to indirect climate benefits through reduced greenhouse-gas emissions and faster payback of carbon debts1. Biofuel expansion may also cause direct, local climate changes by altering surface albedo and evapotranspiration2, but these effects have been poorly documented. Here we quantify the direct climate effects of sugar-cane expansion in the Brazilian Cerrado, on the basis of maps of recent sugar-cane expansion and natural-vegetation clearance combined with remotely sensed temperature, albedo and evapotranspiration over a 1.9?million?km2 area. On a regional basis for clear-sky daytime conditions, conversion of natural vegetation to a crop/pasture mosaic warms the cerrado by an average of 1.55 (1.45–1.65)?°C, but subsequent conversion of that mosaic to sugar cane cools the region by an average of 0.93 (0.78–1.07)?°C, resulting in a mean net increase of 0.6?°C. Our results indicate that expanding sugar cane into existing crop and pasture land has a direct local cooling effect that reinforces the indirect climate benefits of this land-use option.
