In some parts of the world, the human cost from cooking-related air pollution is increasing. The change over time in the population lacking access to clean cooking solutions, known as the access deficit, is illustrated for each region in figure 2.7. The plot shows that the global population lacking access to clean cooking has plateaued at around 3 billion. This is because substantial deficit reductions in the two Asian regions are being offset by increases in the Sub-Saharan African region (figures 2.7 and 2.8).