The Paris Agreement, adopted in 2015 by 195 countries, aims to limit global warming to well below 2 degrees Celsius and pursue efforts to limit the temperature increase to 1.5 degrees Celsius above pre-industrial levels. However, since its adoption, the agreement has faced challenges, including the withdrawal of several countries.

As of 2021, only one country has officially withdrawn from the Paris Agreement. In 2019, the United States, the second-largest greenhouse gas emitter after China, announced its intention to withdraw from the agreement, citing economic concerns and a desire to prioritize the American economy over environmental concerns. The formal process of withdrawal was initiated in November 2019 and became effective on November 4, 2020.

Despite the withdrawal of the United States, the Paris Agreement remains in force with the participation of 194 other countries. This demonstrates a strong commitment to addressing climate change and reducing greenhouse gas emissions worldwide.

Since the Paris Agreement was adopted, there have been concerns about the insufficient ambition of countries` emissions reduction commitments. This led to the development of the Katowice Rulebook at the 2018 United Nations Climate Change Conference, which aims to strengthen the transparency and accountability of countries` commitments.

In conclusion, only one country, the United States, has officially withdrawn from the Paris Agreement. Despite this setback, the overwhelming majority of countries remain committed to limiting global warming and reducing greenhouse gas emissions. The Paris Agreement continues to be a crucial international effort to address the urgent issue of climate change.