明確氣溶膠對云反照率的影響（實(shí)質(zhì)上是它們對氣候的作用力效應(yīng)）是現(xiàn)代氣候科學(xué)的最大挑戰(zhàn)之一,。
人們經(jīng)常默認(rèn)：持續(xù)的高不確定性主要與由人類活動造成的排放有關(guān)。換句話說,，如果人類的影響能夠被更好地了解,，總體效應(yīng)也就會被更好地了解。
現(xiàn)在Ken Carslaw及同事發(fā)表了代表對可能會影響云亮度的氣溶膠和前體氣體排放以及其他因素的28個參數(shù)所做的一項(xiàng)分析,。
他們發(fā)現(xiàn),，自工業(yè)化前期（公元1750年左右）以來氣溶膠作用力所發(fā)生變化的只有34%與人類活動造成的排放有關(guān)，而45%的變化與火山二氧化硫的自然排放,、海洋二甲基硫化物和其他自然來源有關(guān),。
這項(xiàng)工作向純粹通過在了解人類活動產(chǎn)生的氣溶膠方面的發(fā)展所能獲得的進(jìn)展程度提出了質(zhì)疑，同時也表明我們需要對工業(yè)化之前的環(huán)境機(jī)理有更多了解,，當(dāng)時的自然氣溶膠居主導(dǎo)地位。（生物谷Bioon.com）
生物谷推薦的英文摘要
Nature doi:10.1038/nature12674
Large contribution of natural aerosols to uncertainty in indirect forcing
K. S. Carslaw,，L. A. Lee,，C. L. Reddington，K. J. Pringle,，A. Rap,，P. M. Forster，G. W. Mann,，D. V. Spracklen,，M. T. Woodhouse，L. A. Regayre& J. R. Pierce
The effect of anthropogenic aerosols on cloud droplet concentrations and radiative properties is the source of one of the largest uncertainties in the radiative forcing of climate over the industrial period. This uncertainty affects our ability to estimate how sensitive the climate is to greenhouse gas emissions. Here we perform a sensitivity analysis on a global model to quantify the uncertainty in cloud radiative forcing over the industrial period caused by uncertainties in aerosol emissions and processes. Our results show that 45 per cent of the variance of aerosol forcing since about 1750 arises from uncertainties in natural emissions of volcanic sulphur dioxide,， marine dimethylsulphide,， biogenic volatile organic carbon， biomass burning and sea spray. Only 34 per cent of the variance is associated with anthropogenic emissions. The results point to the importance of understanding pristine pre-industrial-like environments,， with natural aerosols only,， and suggest that improved measurements and evaluation of simulated aerosols in polluted present-day conditions will not necessarily result in commensurate reductions in the uncertainty of forcing estimates.
