After the record breaking rainfall of Hurricane Harvey we now have Hurricane Irma, the most powerful storm ever recorded in the Atlantic. Already devastating small outlying caribbean islands, it's heading for the larger British Virgin Islands, Puerto Rico, Dominican Republic/Haiti, Cuba and others, homes to million of people. Projections vary but it looks very possible that it will make landfall as a major hurricane in Florida sometime on Sunday. The conspiracy oriented site Geoengineering Watch has already started to claim that Irma (and Harvey) were somehow deliberately created, steered, or intensified. http://www.geoengineeringwatch.org/hurricane-irma-manipulation-objectives-and-agendas/ The linked historical document is an overview of government weather modification research written in 1966 (51 years ago). It does indeed say And yes it would. However this does not mean that they can actually do it. In fact the documents goes into detail that the only one of these things they actually think they could currently do with any success was augment water supplies by cloud seeding with small planes and ground based silver iodide generators. This is something that has been done since the 1950s. It does not steer hurricanes. But no effects on hurricanes. When they discuss the current state of hurricane research they say: So if 50 years ago they were in the very early stages of thinking about how they could modify a hurricane, would it not make sense to assume that now they would have figured it out? Yes and no - they figured it out, but what they figured out was that it could not be done. There was actually a couple of decades in which hurricane modification research was done (most notable Operation Storm Fury) the research largely focussed on obtaining accurate measurements of the conditions around the genesis of a hurricane and its subsequent track and development, and then building predictive models. NOAA did conduct several practical experiments in Hurricane modification, but the results were inconclusive. Hurricanes vary in their paths naturally, and any effect of the seeding was undetectable. http://www.aoml.noaa.gov/hrd/about_hrd/stormfury_era.html However the research did pay off in a greater understanding of the physics of hurricanes and other storms. With that greater understanding came the realization that modification attempts were not going to work: The 1985 paper made this conclusion clear: So far from 70 years of hurricane modification, there were two decades in the 1970s and 1980s when they looked into it, and eventually figured out it could not be done. Hurricane modification is still a desirable goal. But the research focus is still on measuring, modelling, and predicting. The more we know about hurricanes, the less likely it seems that we will ever be able to control them with any degree of success. But research continues.