Encouraging cloud formation over the oceans by spraying seawater into the air would be roughly as helpful as pumping the stratosphere full of particles.
Such claptrap is the bedrock of countless Hollywood movies in which an intrepid whistleblower dodges black helicopters, robotic-like thugs in black suits, and spraying bullets to triumph over corporate evil.
According to PG Economics, a biotechnology consultancy, GM crops have reduced pesticide spraying by about 224m kg over the past decade, and have also greatly reduced greenhouse-gas emissions from agriculture.