Mark D. Schwartz is a synoptic climatologist and phenoclimatologist. His main research interests are plant-climate interactions during the onset of spring and autumn. He has received seven National Science Foundation grants, authored over sixty publications, and recently edited a book entitled Phenology: An Integrative Environmental Science. Phenology is the study of periodic biological events in the animal and plant world as influenced by the environment, especially temperature changes driven by weather and climate. Wide ranges of phenomena are included, from first openings of leaf and flower buds, to insect hatchings and return of birds. Each one gives a ready measure of the environment as viewed by the associated organism. Thus, timings of phenological events are ideal indicators of the impact of local and global changes in weather and climate on the earth’s biosphere. Schwartz is also co-founder of the USA National Phenology Network (USA-NPN).