【明報專訊】Global issues need to be addressed by international cooperation. This is true not only for addressing the pandemic, but also for tackling climate change. Following last week's climate change summit attended by China, France and Germany, the US will convene a virtual climate summit this week. To avoid the irreversible destruction caused by climate change, the international community must reach ''net-zero emissions'' by the middle of this century. Developed countries and developing nations should accelerate emission reduction in accordance with the principle of ''common but differentiated responsibilities (CBDR)''.