Martin's research is about understanding how plants respond to increasing CO2, temperature and changing water availability. He is also interested in how this response of the vegetation to global change, affects the rate of climate change. He is particularly interested in ways to utilise experimental and satellite data to develop evidence-based models with a predictive capacity.

Martin is the co-chair of the management committee for the Community Atmosphere Biosphere Land Exchange (CABLE) model, Australia's community land surface model.