Supertankers and Military ships of various nations likely are being used for Stratospheric aerosol injection

Proposed tethered balloon to inject aerosols into the stratosphere.

If you look at this graphic from the article on Stratospheric Aerosol injuection by  wikipedia you can see one way this could be done. You send up a weather balloon with a 1/4 inch tube that contains whatever you want to inject into the atmosphere and you leave the weather balloon up while you travel say the pacific Ocean from say China to the U.S. with something like a supertanker or a container ship. You tell people this is a weather balloon you have aloft all the while you are spraying stuff at altitude into the air. This then affects the weather, especially in the Western United States to continue the drought another 20 years after the one we have just had. This also dims the sun to a greater and greater degree which changes weather worldwide which is good for some people but definitely bad for the western United States because of the drought it is causing.

This is also likely why China and Russia are not participating in Global Climate change talks in Europe also because this is likely what they are doing instead.