According to the Organising Committee at the start of the talks, the key expected result was an agreement to set a target to limit global warming to „well below 2°C“ Celsius above pre-industrial levels. The agreement states that net-zero anthropogenic greenhouse gas emissions will be achieved in the second half of the 21st century. In the adopted version of the Paris Agreement, the parties will also „make efforts“ to limit the temperature increase to 1.5°C.  The 1.5°C target will require zero emissions between 2030 and 2050, according to some scientists.  In fact, research clearly shows that the costs of climate inaction far outweigh the costs of reducing carbon pollution. A recent study suggests that if the U.S. fails to meet its Paris climate goals, it could cost the economy up to $6 trillion in the coming decades. U.S. envoys continued to participate in UN climate negotiations as required to shore up the details of the deal. Meanwhile, thousands of leaders nationwide have stepped in to fill the void created by the lack of federal climate leadership, reflecting the will of the vast majority of Americans who support the Paris Agreement. Among city and state officials, business leaders, universities, and individuals, there has been a wave of participation in initiatives such as America`s Pledge, the U.S. Climate Alliance, We Are Still In, and the American Cities Climate Challenge. .