Climate change is more than just warming.

The IPCC report says:

Impacts from recent climate-related extremes, such as heat waves, droughts, floods, cyclones, and wildfires, reveal significant vulnerability and exposure of some ecosystems and many human systems to current climate variability (very high confidence). Impacts of such climate-related extremes include alteration of ecosystems, disruption of food production and water supply, damage to infrastructure and settlements, morbidity and mortality, and consequences for mental health and human well-being. For countries at all levels of development, these impacts are consistent with a significant lack of preparedness for current climate variability in some sectors.

A few pages afterwards they list high confidence for climate change attributed water issues in the US West Coast.

The IPCC report is a really nice document and might be one of the best sources for understanding climate change.

FWIW, [I heard that] arid ecosystems might arise from cooler and drier climate, not only warmer and drier ones. Thus, if global warming makes Gulf Stream disappear and it leads to cooling of some areas it used to affect, they may become arid geologically soon. But I am not an expert, this is just how I imagine it could happen.

I'm not sure, but I heard this and asked an expert I know (an economist who studies global warming) who confirmed it.