Atmospheric CO2 growth is driven by anthropogenic emissions from fossil fuel burning and land use, but mysteriously, the natural carbon cycle feedbacks over land and ocean have been keeping up with the magnitude of anthropogenic emissions, absorbing ~50% of the anthropogenic emissions so far. Thus, achieving the climate goal of limiting temperature increase < 2°C by the end of this century critically depends on reductions of anthropogenic emissions and how the natural carbon sources and sinks will change in the future. However, large uncertainties still exist in the spatiotemporal distributions of CO2 sources and sinks, and the processes that control the natural carbon feedbacks. In this talk, I will focus on how satellite observations from Orbiting Carbon Observatory -2/3 (OCO-2/3) (launched in 2014 and 2019 respectively) in combinations with modeling tools and other observations contribute to improve quantification of fossil fuel emissions and understanding of the interactions between climate and natural carbon cycle over tropics, high latitudes and the impact of extreme events. In this end, I will discuss challenges and future opportunities.