China, India, Russia, and Japan, among the world’s largest emitters, must “really step up” and begin to reduce greenhouse gas emissions, according to US Special Presidential Envoy for Climate Change John Kerry, who also urged all nations to increase their ambition in the fight against climate change. Kerry joined UN Secretary-General Antonio Guterres for a virtual event on Friday to commemorate the United States’ re-entry into the Paris Agreement. Government pledges to reduce carbon dioxide and methane emissions are now insufficient, he added, to keep global warming to ...