Greenhouse gas emissions driving catastrophic global warming, coastal cities to be submerged by 2050.
Greenhouse gas emissions, like CO2, are causing global warming, leading to severe climate changes. The USA and China are top emitters, contributing 40% of global CO2 emissions. Developed and developing countries together emit 90% of these gases. Rising ocean levels threaten coastal areas by 2050 and risk extinctions of insects and animals. Urgent action is needed to cut emissions for the future.