The scientific theory of human-induced climate change is well established and goes back almost two centuries. Solar energy drives the earth’s climate, and the atmosphere is the principal component of the system that maintains the earth’s radiative balance. As a result of human activities such as fossil fuel-based energy consumption and deforestation, heat-intercepting greenhouse gases are emitted into the atmosphere. Capable of absorbing thermal radiation, these greenhouse gases accumulate in the atmosphere and affect the radiative balance of the earth. In the period of just two hundred and fifty years after 1750, atmospheric concentrations of the most important greenhouse gases, namely carbon dioxide, methane and nitrous oxide have risen by 40%, 150%, and 20%, respectively. As a consequence of the higher quantity of greenhouse gases in the atmosphere, global average temperatures have risen by 1.1 °C over the same period. In addition to increasing global temperatures, it is easy to find empirical evidence about anthropogenic climate change in the climate system. Ocean acidification, the increasing heat of the oceans, rise in sea levels, destruction of coral reefs, melting ice sheets, and retreating glaciers are listed among the most critical impacts of climate change. The scientific consensus on climate change can be found in the climate science literature. According to the most quoted evidence of the consensus among scientists, 97% of the scientific papers published in scientific journals accept that climate change is occurring, and the main cause is human activity. The Intergovernmental Panel on Climate Change, which is the leading scientific authority on climate change, states, in its 5th climate assessment report (2013), that the “Warming of the climate system is unequivocal, and since the 1950s, many of the observed changes are unprecedented over decades to millennia. The atmosphere and ocean have warmed, the amounts of snow and ice have diminished, sea level has risen, and the concentrations of greenhouse gases have increased…It is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century…”

The picture emerging in the scientific field shows that the sustainable solution to climate change lies primarily in reducing human-induced greenhouse gas emissions. The key document signed in the international arena on climate change is the United Nations Framework Convention on Climate Change (UNFCCC), which was signed in 1992. In Article 2 of the Convention, it is stated that the ultimate goal of the UNFCCC “is to fix the greenhouse gas concentrations in the atmosphere at a level that will prevent a dangerous human intervention to the climate system.” Conversely, the distinction between developed and developing countries, especially in terms of responsibilities regarding greenhouse gas reduction has become an important problem to be overcome in international negotiations. For example, in Article 3 of the UNFCCC, which lists the basic principles to be followed to achieve the ultimate goal, concepts such as equity, development, precaution, and sustainability are highlighted. According to these principles, “the climate system should be protected for the benefit of present and future generations and by the principle of equity.” As a requirement of the principle of equity, the responsibilities of developed and developing countries should be common but following differentiated responsibilities and respective abilities.

Within the Kyoto Protocol, which was negotiated within the scope of the UNFCCC and signed in 1998 and whose implementation period started in 2005, developed countries committed to cutting their average greenhouse gas emissions by 5%. The distinction between developed and developing countries in terms of emission reduction commitments has been one of the most prominent aspects of the Kyoto Protocol. Another internationally important document, signed in 2015, is the Paris Agreement. Unlike the Kyoto Protocol, in the Paris Agreement, the main target is to hold the increase in average temperatures in the twenty-first century to well below 2 °C compared to the pre-industrial period. In addition to the 2 °C target, it is decided that efforts should be pursued to limit the temperature increase to 1.5 °C above preindustrial levels. Unlike the Kyoto Protocol in which countries aim to participate in an emission reduction target determined at the international level, the parties in the Paris Agreement set a target according to themselves. Although it is presented as a single agreement, the Paris Agreement consists of different national commitments prepared and announced by the parties, in line with their own conditions. Although international participation against climate change has been achieved in the agreement, it is seen that the de facto distinction between developed and developing countries in the UNFCCC is maintained.

The fact that there are developed and developing countries among the G20 countries, including Turkey, makes it possible to analyze the political divergence in the fight against climate change since the UNFCCC. However, the fact that the G20 countries constitute 63% of the world’s population, 80% of the national income, 78% of the energy supply, and 81% of the fossil-fuel based carbon dioxide emissions as of 2017 helps to interpret the results of the analysis in terms of the world. The cluster analysis based on per capita income and carbon dioxide emissions show that the gap between developed and developing countries did not close in the 1990-2017 period. The increase in the total emissions of countries such as China and India is remarkable. However, within the G20, developed countries’ per capita emissions are still relatively high compared to developing countries. As a global environmental problem, human-induced climate change requires the participation of all countries. However, demographic, economic, and technological differences between countries indicate that achieving global cooperation is not as easy as desired. The sustainable solution or management of climate change necessitates reducing these differences between countries. At this point, the aim should not only be to put pressure on developing countries to reduce their greenhouse gas emissions but also to build a structure that helps developing countries to gain the institutional, economic, and technological capability and capacity they need in the fight against climate change.