The frequency and the intensity of climatic disruptions pose a significant threat to human lives and livelihoods, necessitating immediate attention and effective mitigation measures. But the consequences of climatic vulnerabilities are not the same for all. Typically, the effects of climate change affect the impoverished disproportionately: low- and middle-income countries experience greater severe effects when compared to their wealthier counterparts. Concurrently, climate catastrophe is also shaped by the inherent socio-economic disparities within countries. An examination of the worldwide population divided into the bottom 50%, middle 40%, and top 10% based on their losses, emissions, and capacity to fund global climate initiatives provides a comprehensive understanding of climate disparities and a practical method for identifying the main sources of financing for policies aimed at reducing climate inequality.

Between 2020 and 2021, a close linkage between global GDP and carbon emissions has been visualised, with both experiencing significant growth rates of 5.9% and 6%, respectively. This shows that economic output and greenhouse gas emissions continue to remain intertwined in global production processes. But this linkage differs across countries. For instance, a recent study by the World Inequality Lab observed, “The global top 10% are responsible for almost half of global carbon emissions, and the global top 1% of emitters are responsible for more emissions than the entire bottom half of the world’s population.” Addressing regional climate inequalities is, therefore, a prerequisite for sustainable and inclusive development of all segments of societies. Moreover, it has a systematic connection with achieving Sustainable Development Goals and reducing inequalities (SDG10) and climate action (SDG13). In this study, the estimates are based on the Climate Inequality Report 2023.

All individuals contribute to emissions, albeit in varying degrees. The per capita emission of the bottom 50% is 1.4 tCO2/person, which accounts for 12% of the total emissions. The middle 40% emits 6.1 tCO2/person, while the top 10% has 28.7 tCO2/person representing 40% and 48% shares, respectively, of the total emissions. The carbon emissions per capita of the wealthiest 1% is 101 tonnes (16.9% of the total). The consumption and investment decisions made by a meagre share of the population are resulting in far greater ecological damage than the combined consequences of the entire bottom half of the global population. The carbon footprint of the top 10% of the population in North America is unquestionably the largest while the carbon footprint of the lower half of the population in sub-Saharan Africa is the smallest. The carbon footprint of a typical American citizen is nearly ten-fold that of an Indian. Over time, such disparities in per capita carbon emission become greater within countries than between countries.

The phenomenon of climate change has exacerbated economic disparities. Countries in lower latitudes are more severely affected by climate change than those in higher latitudes. Moreover, low-income households are relatively more vulnerable than higher-income households due to their dependence on employment in agriculture and construction. Conversely, high-income households are less likely to depend on employment income from industries vulnerable to natural catastrophes. Furthermore, the lower income strata allocate a disproportionate share of their earnings towards purchasing food and other items, making them more vulnerable in case of sudden increases in food and energy prices following natural catastrophes. The climate-dependent agriculture of less developed nations also bears the brunt of lower agricultural output. Evidence suggests that several economically disadvantaged areas are experiencing 30% or more agricultural productivity declines due to climate change, directly impacting poverty and food insecurity. Such consequences are most pronounced in regions that have made the least contributions to past emissions.

A number of countries in the global South are far poorer than they would have been if climate change had not occurred. For many tropical and subtropical countries, this trend is projected to persist and lead to revenue losses of over 80% by the end of the century. Within countries, economically disadvantaged population groups experience more severe losses from climate effects, which widen the inequalities. According to a report, the bottom 50% of the global population accounts for 12% of global emissions; however, it bears 75% of the relative economic losses caused by climate change. In contrast, the top 10% of the global population accounts for almost 50% of all emissions and, yet, experiences a mere 3% of relative income losses. Moreover, the estimates of WIL, 2023 suggest that the income losses resulting from climate hazards for the bottom 40% are 70% higher than the average in low- and middle-income nations. Nine of the ten countries most exposed to significant risks of flooding are low-income or middle-income countries. Assessment informs that approximately 23% of the global population is estimated to be exposed to flood threats. The vast population size and extensive coastlines of China and India, respectively, amount to the largest headcounts of flood exposure. Nearly 85% of the population in a comprehensive sample of countries resides in regions where impoverished individuals are disproportionately vulnerable to droughts.

Projections suggest that there could be a significant rise in mortality in the global South by the end of the 21st century. The varying climatic conditions have intensified the challenges of eradicating malaria and dengue in countries with low Human Development Index. In fact, climatic variations and their evolving patterns often facilitate the re-emergence of certain vector-borne diseases. There is also evidence of a detrimental impact on mental well-being, particularly that of the underprivileged. Women and those belonging to the lower socio-economic strata experience a higher prevalence of mental health issues compared to men and those belonging to the upper economic strata. Response and adjustment to climate effects are contingent upon financial resources. Resource availability among the climate-vulnerable population is less. Such an imbalance has implications for accommodation and mitigation of climate-induced challenges.

Efforts at reducing emissions are significantly lower among high-emitting groups. At the same time, climate finance remains inadequate in mobilising the promised amounts for developing countries. The adaptation funding gap is vastly underfunded and needs urgent attention. Relying on international transfers will not be enough to tackle climate inequality. Substantial modifications to global and domestic tax structures are required to ensure equitable distribution of mitigation and adaptation efforts across the population.

Udaya S. Mishra is Professor, Department of Biostatics at the International Institute for Population Sciences, Mumbai. Balakrushna Padhi is Assistant Professor, Department of Economics and Finance at the Birla Institute of Technology and Science. Ishawar Choudhary is pursuing a PhD in Economics at BITS Pilani. The views do not represent the official stance of the affiliated institutions.