Climate models project an even warmer, drier Southwest. As water is life in the desert, these projected changes may profoundly impact southwestern ecosystems and human society.
Records of past climate show that the Southwest’s climate has been highly variable over time, but now human activity is altering that climate to an unprecedented state. Climate models project that the Southwest will become even warmer and more arid than it is today. Because water is such a limiting resource for life in desert environments, a more arid climate could profoundly impact southwestern ecosystems and human society. This overview describes only some of those potential impacts to ecosystems in the Southwest. Because any impact to a part of an ecosystem can affect the whole, climate change impacts can cascade, indirectly affecting the biological processes of many different organisms. In addition, different impacts can interact with each other and compound the effects of climate change. For example, in the Sonoran desert, the combination of grasses invading the desert and an increased frequency of fires could devastate saguaro cacti. While scientists may not be able to forecast the exact impacts of climate change, human-induced climate change will clearly have consequences for the arid Southwest.
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Last updated: February 3, 2015