WHAT IS SHOWN: Saguaro cactus loss in Saguaro National Park between 1935 and 2010. It can be easy to fall into the trap of ascribing any landscape change to "climate change," but the story of saguaros is much more complex. Many of the mature saguaros in the 1935 photo are thought to have died during severe freeze events. With a warmer climate, these freeze events may become less common. So climate change might actually be good news for the saguaro, right? There's more to it, however: saguaro seedlings are sensitive to drought, and recent prolonged drought and record heat has severely limited seedling establishment and survival. In addition, warmer temperatures also promote the spread of invasive buffelgrass, which fills in the spaces between saguaros and makes wildfire much easier to spread.