It is obvious that the way much coffee is grown affects many aspects of life, from the local environment to the global ecology. But consumers do have a choice. They can purchase shade-grown coffee whenever possible, although at a higher cost. The future health of the planet and mankind is surely worth more than an inexpensive cup of coffee. 

这是2015年高考英语陕西卷阅读理解C中的一小段，请问 shade-grown coffee 是什么意思？