The Machine That Saved the World — Murray Leinster

What if the inhabitants of Earth received a message from the future warning of an upcoming calamity that could wipe out the entire planet? That's the plot that propels "The Machine that Saved the World" by prolific SF luminary Murray Leinster. When the denizens of the future propose a solution, however, one man harbors suspicions. Is he merely paranoid, or are his misgivings well founded?