The Paris Agreement to combat climate change went into effect on Nov. 4—a landmark deal to tackle global warming amid growing fears that the world is becoming warmer even faster than scientists expected. So far 96 countries, accounting for just over two-thirds of the world’s greenhouse gas emissions, have formally joined the accord, which seeks to limit global warming to 2 degrees Celsius (3.6 degrees Fahrenheit). Secretary General Ban Ki-moon observed the event in a discussion with civil society groups at U.N. headquarters in New York to hear their concerns and visions for the future. Ban praised the civil groups for mobilizing hundreds of millions of people to back fighting climate change, but warned that the outcome remains uncertain. “We are still in a race against time. We need to transition to a low-emissions and climate-resilient future,” Ban said. Scientists praised the speed at which the agreement, signed by over 190 parties last December in Paris, has come into force, saying it underscores a new commitment by the international community to address the problem, which is melting polar ice caps, sending sea levels rising and transforming vast swaths of arable land into desert.