Fallen Angels by Jerry Pournelle, Larry Niven and Michael Flynn
Free at webscription.net
I had completely forgotten about this book. I read it a long time ago so it
may will be dated.
Synopsis
"That government, dedicated to saving the environment from the evils of technology, had been voted into power because everybody knew that the Green House Effect had to be controlled, whatever the cost. But who would have thought that the cost of ending pollution would include not only total government control of day-to-day life, but the onset of a new Ice Age "