That's another vast question. In the mountains of both Canada and the United States, we are indeed seeing not necessarily a major decrease in precipitation over the whole year but a change in precipitation patterns. Before the advent of climate change two or three decades ago, when it started to become very noticeable, a high proportion of winter precipitation fell as snow. This meant that a reservoir of snow accumulated throughout the winter, and gradually melted from spring and summer onwards. This made it possible to have a relatively substantial flow rate in rivers that descended from the mountain ranges, providing water precisely when it was needed, that is, during the summer period, essentially for irrigation.
What we are seeing more and more is that the overall amount of drinking water that falls during the year doesn't decrease that much, but falls more and more in the form of rain in the winter, which has a number of consequences. First of all, the accumulation of snow cover is much less. As a result, in spring and summer, there will be a lot less snow melting and feeding the flow of the rivers—