Well, let's just rough out the experiment, shall we?<p>First, we need to establish that human activity can change the climate. For the sake of argument, let's try rainfall in the Sonora Desert. What we could do is to burrow an underground canal from the Gulf of California into Laguna Salada, and from there to the Salton Sink. This would establish shallow, inland, saltwater seas upwind of the desert, in a very sunny area, as a source of atmospheric humidity. Evaporation would be further encouraged with sea salt manufacturing beds and Salicornia bigelovii plantations.<p>(It would also displace thousands of people whose homes would now be underwater, but let's handwave that aside for now.)<p>We then erect solar-powered ionization towers downwind of the new seas, to stimulate cloud formation via charged particles of dust. Those clouds will tend to blow east over the desert and rain out. To extend the rainfall further east, we simply plant dry-tolerant plants--such as sorghum, lucern, and field pea--in the newly wet areas, to recycle moisture back into the air via transpiration.<p>Results of the experiment will compare weather patterns in Yuma and Mexicali before and after the megaproject.<p>And then, after spending (optimistically) $20 billion on the subterranean saltwater tunnels, and $100 million on the cloud seeders, we can collect our $10000. Yay!<p>In comparison to what it would cost to test experimentally a hypothesis that states the entirety of global human economic activity is influencing weather patterns, you will have to spend an amount capable of simulating a portion of the global human economy towards a directed experimental purpose. $10000 isn't even a round-off error.<p>You would be better off buying up unproductive arid land and leasing it to cattle ranchers as semi-arid grazing land afterward.