I have a hard time deciding if you are actually this obteuse...
Or if this is your way of derailing discussions when you dont like where they are going. Its not an endearing habit of yours.
OF COURSE drought happened in the past, the point is that these changes will lead to more droughts, and more widespread droughts. THINK about whats involved if we have to change to a new global distribution of agriculture!
The problem isnt that the world will change, its that we will have to try to adapt to it smoothly or face very serious problems. We have built our culture and our infrastructure on the way the climate is, if that changes then we are going to have to expend great resources to adapt.