1) According to Steven Johnson, governments or religions fear air pumps and electrical machines because governments and religions should fear scientific progress in general. To explain further, air pumps and electrical machines (especially during John Priestly’s time) created ideas and theories that revolutionized science, toppling ideas that had been accepted for thousands of years. This power to change the traditional order so suddenly and so thoroughly, is terrifying to the established government and religion, especially if the governmental or religious ideals are based upon the previously accepted theory that one man has just debunked. Scientific revolution can cause people to question the established “rules,” which can lead to revolution and violent overthrow. And it did. Priestly supported both the American and the French Revolutions and attacked the doctrine of the trinity, embarrassing local nobles. But his work was too controversial and lead to his forced expulsion from Europe. I think the idea can be broken down into a simple cause and effect. New discoveries in science lead to revelations and even more questions, and free thought encourages free thought, which can cause a free thinker to question the established order, which can lead to that person rebelling against the established order. Governments and religions want docile followers, not rebellious leaders, which is why they should fear air pumps and electrical machines.
2) I think Johnson’s work sheds new light on climate research and new ways of harnessing energy, but I think it comes down to fear of losing money more than fear of “uprising” or “revolution.” For example, the current system (coal and oil) pays too well to make the expensive and potentially risky investment in a new system (wind and solar). Governments and religions can purposefully transfer their own fear of losing money into fear and uncertainty about the risks of a new system (or even if that new system is necessary in the first place) into their population. That’s scary.