Watson received a PhD in gas phase chemical kinetics (atmospheric chemistry) from Queen Mary College, University of London in 1973. He has received awards for his contributions to science, including the NAS Award for Scientific Reviewing from the National Academy of Sciences in 1992, the American Association for the Advancement of Science Award for Scientific Freedom and Responsibility in 1993, the insignia of Honorary Companion of St Michael and St George from the British Government in 2003, and the Champions of the Earth Award from the United Nations Environment Programme in 2014. In 2020 he was elected to the American Philosophical Society.