The Paris Agreement is an agreement within the United Nations Framework Convention on Climate Change (UNFCCC), dealing with greenhouse gas emissions mitigation, adaptation, and finance, starting in the year 2020.

Statement 1 is incorrect. Not all UN member countries signed the Paris Agreement when the question was asked by the UPSC. As of today, 195 parties (194 states and the European Union) have joined.

Statement 2 is correct. The Paris Agreement's central aim is to limit global warming to well below 2 degrees Celsius above pre-industrial levels and to pursue efforts to limit the increase to 1.5 degrees Celsius.

Statement 3 is incorrect. The Paris Agreement acknowledges the historical responsibility of developed countries and calls for them to provide financial assistance to developing countries for climate change mitigation and adaptation. However, the specific amount of $1000 billion per year is not mentioned in the agreement. Rather, $100 billion was agreed upon but modalities are yet to finalise.