There is an almost linear relationship between global warming and cumulative carbon dioxide (CO2) emissions. The United Nations Framework Convention on Climate Change (UNFCCC) in 1992 noted that per capita emissions in developing countries are still “relatively low” and that their share in the global emissions will grow to meet their social and developmental needs.
The Convention recognises the ‘common but differentiated responsibilities and respective capabilities’ (CBDR-RC) principle. This means different States have different responsibilities and respective capabilities in tackling climate change. This principle has been reaffirmed in the Paris Agreement, whose main aim is to hold “the increase in the global average temperature to well below 2 degrees C above pre-industrial levels’‘ and pursue efforts “to limit the temperature increase to 1.5 degrees C above pre-industrial levels”.
According to the Intergovernmental Panel on Climate Change’s Sixth Assessment Report (IPCC AR6), every 1,000 billion tonnes of CO2 in emissions causes an estimated 0.45 degrees C rise in the global surface temperature. Axiomatically, limiting the rise in global temperature to a specific level means limiting cumulative carbon dioxide emission to within a carbon budget.
