What to wear both soft and lightweight and warm? A few months ago perhaps the answer is still cashmere, but now there is an increasingly popular single product desirable instead, it is the Tibetan people's necessities of life - yak. Maria Hannah Bass from WCMC recently at the UN International Conference on Deserts and Desertification held in Europe explained why yak cashmere can become a substitute for cashmere while preventing land desertification. I do not know whether this finding will improve herdsmen's economic income.