Yesterday there was an article about how a researcher thinks farmers may be slightly changing the weather in Chicago at the end of the summer. With technology, farmers have been able to increase the density of crops in fields in the Midwest and more plants put additional water vapor into the air. Over the decades, late summer weather in Chicago has been less hot but more humid.
Also recently there was an article about Bill Gates funding research into equipment that would spray ocean water up into the sky to make whiter clouds, reflecting more sun light.
I'm a fan of making dark surfaces lighter in color, which would reflect energy away. Making a roof white instead of black, for example, is the easiest and most passive thing to do. It'll also decrease summer cooling costs, which is great because that's when the demand for energy is the highest. Steven Chu, the US Energy Secretary, is also pushing for this.