Heads of state and other leaders affirmed their commitments to fight climate change at the One Planet Summit in Paris on December 12, on the two-year anniversary of the Paris Agreement. Their calls for concrete action came as concentrations of the greenhouse gas carbon dioxide reached their highest level in 800,000 years. CO2 emissions rose 60% between 1990 and 2014. In the last three years, global emissions had leveled off, but they recently began to rise again.
source: worldbank