Trees often get a bad rap because of the potential to spread fire in the crown, but that is seldom a hazard to structures. There are exceptions, however.
Trees: Possible Problems
Major concerns from trees are those that they spread embers around a neighborhood. Pines, in particular, can have cones that ignite and are carried a great distance by the wind. Another problem common to all trees is that the leaves or needles that drop onto roofs or other places become very dry tinder in fire season. Any trees with limbs that are near or above power lines are especially hazardous.
Trees: Potential Solutions
The rule of thumb is that trees should not have branches that come within 6 feet of the vertical plane of a house.
Obviously, there are a number of trees that violate this, so some judgment should be used as to the remedy. A good idea is to evaluate all of your trees and make both short-term and long-term plans, from pruning to replacement. Those with branches that overhang the roof or power lines should be pruned to eliminate or minimize the overhang. In the case of power lines, those crossing your property are your responsibility and not that of the power company. A licensed tree pruner should be used to remove such branches and any others that might later grow into a hazard.
If the tree is deciduous, then it will probably lose its leaves before the fire season, so it may not be a flammability hazard at all. Placing deciduous tree on the southerly side of a building is good energy saving practice. Trees in this location shad the building in the summer and permit passive solar heating in the winter. However, it is still an indirect hazard because of leaves that are dropped (typically just before the fire season).