A new study published in Nature magazine shows that dry climates across the world have increased. They note that “About 5.7% of the global total land area has shifted toward warmer and drier climate types from 1950–2010, and significant changes include expansion of arid and high-latitude continental climate zones, shrinkage in polar and midlatitude continental climates….”
At the same time, the area of higher latitude climate types has decreased and tropical areas have expanded slightly. The study attributes these changes to the 1 degree F increase in global temperature since 1950, which is due primarily to anthropogenic causes such as the burning of fossil fuel.
You can read an article about this study here.