At the end of the course, the participants will be able to: 1.Understand the mechanism of global warming, the role of anthropogenic activities in its rise, and why CO2 is the main target. 2.Explain the working principles of different technologies for reducing CO2 emissions and atmospheric CO2 reduction. Particularly for the hydrogen economy, understand the advantages of using hydrogen as a green fuel, and be familiar with the ecosystem of a sustainable hydrogen economy, e.g., production, storage & transportation, and utilization. 3. Analyze and evaluate the renewable and low CO2 emission alternative energy technologies and utilization options. For green hydrogen technologies, understand simple life-cycle analysis and technoeconomic assessment for model systems. 4. Introduce the general technological & engineering challenges ahead for establishing a hydrogen economy. 5. Connect the ideas in this module to give informed opinions on zero-carbon future pathways.