Richmond Times-Dispatch: WEST POINT In Sweet Hall marsh, the ghosts tell tales. Dead, bone-white trunks known as ghost trees say the marsh along the Pamunkey River is changing. Scientists suspect the trees were exposed to too much water, and possibly salt water, because the sea level — and hence, the river level — is rising. The rising sea is a well-documented effect of global warming. When water warms, it expands. The sea level is rising faster in southeastern Virginia than any other place on …