来自非洲撒哈拉/萨赫勒地区的尘埃排放是气候系统中的一个重要因素，但非洲尘埃之产生的长期历史仍然在很大程度上不为人们所知，部分原因是，人类对非洲尘埃排放的贡献是一个有争议的问题。
现在，通过研究位于西非尘埃柱下一个海洋点上所沉降的沉积物的化学组成及颗粒大小分布，Mulitza等人构建了关于非洲西北尘埃沉降的一个3200年的记录。他们的发现数据显示，由人类诱导的尘埃排放在距今约200年前的商业化农业生产发端期间开始对总尘埃预算有较大贡献，并且从此以后一直在继续增加。 (生物谷Bioon.net)
生物谷推荐原文出处：
Nature doi:10.1038/nature09213
Increase in African dust flux at the onset of commercial agriculture in the Sahel region
Stefan Mulitza,David Heslop,Daniela Pittauerova,Helmut W. Fischer,Inka Meyer,Jan-Berend Stuut,Matthias Zabel,Gesine Mollenhauer,James A. Collins,Henning Kuhnert& Michael Schulz
The Sahara Desert is the largest source of mineral dust in the world1. Emissions of African dust increased sharply in the early 1970s (ref. 2), a change that has been attributed mainly to drought in the Sahara/Sahel region2 caused by changes in the global distribution of sea surface temperature3, 4. The human contribution to land degradation and dust mobilization in this region remains poorly understood5, 6, 7, 8, 9, 10, 11, owing to the paucity of data that would allow the identification of long-term trends in desertification12. Direct measurements of airborne African dust concentrations only became available in the mid-1960s from a station on Barbados2 and subsequently from satellite imagery since the late 1970s: they do not cover the onset of commercial agriculture in the Sahel region ~170 years ago11, 13, 14. Here we construct a 3,200-year record of dust deposition off northwest Africa by investigating the chemistry and grain-size distribution of terrigenous sediments deposited at a marine site located directly under the West African dust plume. With the help of our dust record and a proxy record for West African precipitation15 we find that, on the century scale, dust deposition is related to precipitation in tropical West Africa until the seventeenth century. At the beginning of the nineteenth century, a sharp increase in dust deposition parallels the advent of commercial agriculture in the Sahel region. Our findings suggest that human-induced dust emissions from the Sahel region have contributed to the atmospheric dust load for about 200 years.
