Desert turns forest, Viking giant, and dream inception: this week's science headlines

This week’s science roundup covers China’s Great Green Wall turning the Taklamakan Desert into a carbon sink and related emissions trends, a Viking Age mass grave near Cambridge that includes the skeleton of a towering man who may have undergone trepanation, a study showing that dreams can be subtly seeded to boost problem-solving, and a nature-made Valentine’s gift idea tied to a pink salt lake in Argentina, along with other climate, archaeology and space-related science news.