Regional climate change may arise from changes in global forcing (greenhouse gases, volcanoes, changes in output of the sun) or regional forcing (emissions of sulfate aerosol that are scavenged regionally from the atmosphere near where they were emitted). Another source of regional climate change is changes in land use that changes the regional heating and/or evaporation pattern. Solar radiation that is not reflected after it strikes the ground may (a) warm the soil, (b) warm the air, (c) lead to photosynthesis, or (d) evaporate water. If there is less water on the surface to evaporate (e.g., due to tile drainage) then more solar energy goes to heating soil or air and less water is put into the atmosphere. Marshall et al. (2003) find that draining of land in south Florida likely has created climate change by allowing night time temperatures to dip below freezing more than under natural conditions. Standing water that is warmed by the sun during the day emits more heat at night than bare soil and hence holds the night-time temperature higher.
Reference
Marshall, C. H., R. A. Pielke, Sr., and L. T. Steyaert, 2003: Crop freezes and land-use change in Florida. Nature, 426, 29-30.