The accuracy of a knowledge base can be maintained and improved over time by providing it with feedback -- confirmation or correction of the current categorization.
Uncertainties in the future rate of (temperature) rise, stemming largely from the 'feedback' effects on water vapour and clouds, are topics of current research.
未来（温度）上升率的不确定性很大程度上由水汽和云层‘反馈’效果造成，这些是当前研究的课题。
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Feedback: Concrete feedback about the current state of the system is absolutely priceless.