美国宇航局的新闻地图证实，地球正在变得更绿

美国宇航局的新闻地图证实，地球正在变得更绿

Earth has continued to grow green since the turn of the century and this could help moderate global warming, according to new maps released by the United States National Aeronautics and Space Administration’s (NASA). High levels of carbon dioxide increased photosynthesis, according to authors of a review paper published in Nature Reviews Earth & Environment.

根据美国国家航空航天局(NASA)发布的新地图，自世纪之交以来，地球一直在持续变绿，这可能有助于缓和全球变暖。发表在《自然评论地球与环境》杂志上的一篇评论文章称，高浓度的二氧化碳增加了光合作用。

An updated map (above) released by the United States National Aeronautics and Space Administration’s (NASA) showed how greenness increased between 2000 and 2018 globally. The areas where greenness increased were marked in green and areas where it decreased were marked in brown.

美国国家航空航天局(NASA)发布的最新地图(上图)显示了2000年至2018年全球范围内的绿化情况。绿色增加的区域用绿色标记，绿色减少的区域用棕色标记。

NASA had in February 2019 established that earth was greener than it was in the 1980s. It had computed the data using Moderate Resolution Imaging Spectroradiometer on NASA’s Terra and Aqua satellites.

NASA在2019年2月确定，地球比上世纪80年代更环保。它利用NASA的Terra和Aqua卫星上的中分辨率成像光谱仪计算数据。

The map showed the trend in the "leaf area index"— the amount of leaf area relative to ground area — during the growing season. The second map (below) showed the predicted change in the growing season's "leaf area index" from 2081-2100 relative to 1981-2000. It showed how green cover might look like in the future.

这张图显示了“叶面积指数”的趋势——叶面积相对于地面面积的数量——在生长季节。第二张图(下图)显示了生长季“叶面积指数”在2081-2100年相对于1981-2000年的预测变化。它展示了绿色植被在未来的样子。

A significant increase in green cover in boreal and Arctic regions was observed in the new maps, which researchers attributed to rising temperatures. For example, Svalbard in the high-Arctic saw a 30 per cent increase in greenness, according to Rama Nemani of NASA’s Ames Research Center and co-author of review paper. The green cover grew with an increase in mean summer temperature from to 4.7° Celsius from 2.9° Celsius (37.2° to 40.5° Fahrenheit) between 1986 and 2015.

在新的地图中，北极和北极地区的绿色植被显著增加，研究人员将其归因于气温上升。例如，据美国宇航局埃姆斯研究中心(Ames Research Center)的拉玛·内马尼(Rama Nemani)称，北极高地区的斯瓦尔巴特群岛(Svalbard)的绿化面积增加了30%。内马尼是这篇综述论文的作者之一。从1986年到2015年，夏季平均气温从2.9摄氏度(37.2摄氏度到40.5华氏度)增加到4.7摄氏度，绿色植被也随之增长。

Authors of the paper reviewed more than 250 published articles and found that the global greening was due to increased levels of carbon dioxide in the atmosphere. Interestingly, this phenomenon made earth cooler; as vegetation consumed carbon dioxide, it performed evapotranspiration. According to scientists, global greening since the early 1980s may have reduced global warming by as much as 0.2° to 0.25° Celsius.

这篇论文的作者回顾了250多篇已发表的文章，发现全球变绿是由于大气中二氧化碳含量的增加。有趣的是，这种现象使地球变冷;由于植物消耗了二氧化碳，因此产生了蒸散作用。据科学家称，自上世纪80年代初以来，全球变暖的程度可能已经降低了0.2到0.25摄氏度。

It is ironic that the very same carbon emissions responsible for harmful changes to climate are also fertilising plant growth, which in turn is somewhat moderating global warming,” said Jarle Bjerke of the Norwegian Institute for Nature Research and co-author of the paper.

挪威自然研究所的Jarle Bjerke是这篇论文的合著者，他说:“具有讽刺意味的是，造成气候有害变化的碳排放同时也促进了植物生长，从而在一定程度上减缓了全球变暖。”

Shilong Piao of Peking University, and lead author of the paper, said:This greening and associated cooling is beneficial, but reducing carbon emissions is still needed in order to sustain the habitability of our planet."

这篇论文的第一作者、北京大学的裴石龙说:“这种绿化和相关的降温是有益的，但是为了维持我们星球的宜居性，减少碳排放仍然是需要的。”