[E. Pluribus Unum]

The simple expansion of irrigation on a massive scale, worldwide, plus building tens of thousands of golf courses with super-duper greens control systems, could explain everything.

70% of the earth's surface is covered with water, but you believe that a few measly irrigation systems and golf courses have a greater impact?

Unbelievable.

[muawiyah]

It's the relative rates of evaporation. You have "dry air" blowing over the land and "moist air" blowing over the ocean. The "dry air" will absorb more water than the "moist air" (given the same temperature, right?)

We can even estimate the temperature of the water being used, in general, for irrigation purposes, as well as how much of it is sprayed and so forth, and it turns into a simple mathematical exercise.

Irrigation could very well increase the amount of water evaporated into the air several percentage points.

So, you're the smart guy, give us the answers on this one.