Mountain treelines are rising in response to the climate crisis, a study has found. Scientists from the Southern University of Science and Technology in Shenzhen, China, used remote sensing to map the highest points of patches of tree coverage on mountains. They found that 70% of mountain treelines had moved uphill between 2000 and 2010. On average, treelines moved upwards by 1.2 metres (4ft) a year, but the shift was greatest in tropical regions, with an average increase in elevation of 3.1 metres a year – and in all regions they found the rate of change was accelerating. In total,…