Even those man-made tremors large enough to be an issue are very rare, says a special report by the National Research Council. In more than 90 years of monitoring, human activity has been shown to trigger only 154 quakes, most of them moderate or small, and only 60 of them in the United States. That’s compared to a global average of about 14,450 earthquakes of magnitude 4.0 or greater every year, said the report, released Friday. …

Only two worldwide instances of shaking — a magnitude 2.8 tremor in Oklahoma and a 2.3 magnitude shaking in England— can be attributed to hydraulic fracturing, a specific method of extracting gas by injection of fluids sometimes called “fracking,” the report said. Both were last year. …

With increased drilling to satisfy the country’s thirst for energy, it is important to watch injection and other wells better and consider potential repercussions before starting, the report said. No one has been killed, nor has there been major damage, from man-made quakes in the United States, said the report by the council, which is part of the National Academy of Sciences, a private nonprofit institution that provides expert advice to the government.