Water vapor is the most important greenhouse gas in the atmosphere although changes in carbon dioxide constitute the "control knob" for surface temperatures. While the latter fact is well recognized, resulting in extensive space-borne and ground-based measurement programs for carbon dioxide as detailed in the studies by Keeling et al. (1996), Kuze et al. (2009), and Liu et al. (2014), the need for an accurate characterization of the long-term changes in upper tropospheric and lower stratospheric (UTLS) water vapor has not yet resulted in sufficiently extensive long-term international measurement programs (although first steps have been taken). Here, we argue for the implementation of a long-term balloon-borne measurement program for UTLS water vapor covering the entire globe that will likely have to be sustained for hundreds of years.

中文翻译：

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需要对对流层和平流层下层的水蒸气进行长期，准确的长期测量，并覆盖全球。

水蒸气是大气中最重要的温室气体，尽管二氧化碳的变化构成了表面温度的“控制旋钮”。尽管后一个事实已广为人知，但导致了广泛的星空和地面二氧化碳测量程序，如Keeling等人的研究所述。（1996），Kuze等。（2009年）和Liu等。（2014年），对高对流层和低平流层（UTLS）水蒸气的长期变化进行准确表征的需求尚未产生足够广泛的长期国际测量计划（尽管已采取了第一步）。在这里，我们主张实施一项覆盖整个地球的UTLS水蒸气长期气球测量计划，这可能必须持续数百年。