Crop production is a key component of global food security, but anthropogenic climate change threatens ecosystem function and agricultural productivity. The rising warming of the Earth’s temperature greatly impacts ecosystems globally, with important consequences for microbial diversity. The health of terrestrial ecosystems depends on soil biodiversity, which highly depends on climatic conditions. Microorganisms, which include bacteria, archaea, fungi, and viruses, play critical roles in ecological processes such as the nutrient cycle and decomposition. As global temperatures rise, microbial populations are projected to vary in composition, distribution, and activity. These shifts are influenced by temperature sensitivity, with some species thriving in warmer conditions while others may face decline. Changes in microbial diversity could destabilize ecosystems that rely on specific microbial functions. Soil health, which is directly impacted by microbial activity, could decline if key microbes are lost or altered due to warming. This chapter discusses current knowledge of warming on soil microbial taxonomic and functional diversity, as well as microbial diversity’s contributions to ecosystem processes.