Abstract: The climate crisis and related events are often in the headline in recent years. The climate agreements reflected these concerns and called the researchers’ attention to the urgent need for climate mitigation and adaptation policies. Many countries made new commitments during the latest United Nations Climate Conference (COP26) in November 2021 in Glasgow. In turn, scientists and experts worry that new pledges are not ambitious enough. The first environmental regulation was ratified in Great Britain in 1863. Later, the industrial and agricultural revolution stimulated pollution and brought about the emergence of environmental issues. The first agreement aiming to mitigate environmental pollution and stabilize greenhouse gas concentrations in the atmosphere was the United Nations Framework Convention on Climate Change (UNFCCC), adopted at the Rio Earth Summit in 1992. Behind the European Union, the contribution of the biggest polluter countries to climate change is also significant. The objective of the paper is to investigate the explanatory factors of CO2 emission, focusing on the contribution of economic growth, agriculture, and trade along with free trade and climate agreements on climate change in Non-European Union member states, including the biggest emitters in the past two decades. In addition, it investigates the role of specific free trade agreements in emission cuts. The results showed an increase in CO2 emissions in third countries, the reduction in the impact of agricultural export on greenhouse gas emissions, underlining the potential hidden effect of trade-related emissions between 2000 and 2018. NAFTA was encouraged while EFTA, ASEAN and MERCOSUR reduced emission growth. The USA, China, and Russia have the highest responsibility in controlling climate change. The findings reflect the limited progress and implementation of climate and trade policies and agricultural-related emissions in Non-EU countries.