This lecture provides a recap of the outcomes of COP27, including the establishment of a Loss and Damage fund, weaker language on the 1.5°C goal, and the endorsement of low-emission technology. It discusses the disappointment over unmet expectations and the need for action from countries like the US and China. The lecture also covers the remaining carbon budget to limit global warming and the challenges in reaching net-zero emissions. Various metrics like Global Warming Potential (GWP) and Global Temperature change Potential (GTP) are explained, highlighting the complexities in comparing different greenhouse gases and emission scenarios.