Climate change is said to profoundly alter the world in the decades to come. It would deeply affect the entire planet’s ecosystem, the global economy as well as hundreds of millions of lives. In practice, it already has a notable geopolitical impact, with the potential to radically modify the existing international order. Climate change is a broad term encompassing various phenomena, the most important of which is surely global warming, largely imputed to the boom in CO2 emissions caused by the massive consumption of fossil fuels, animal breeding and deforestation. The rise in the world’s average temperatures, even by a few degrees, could have tremendous consequences on the planet and mankind. It would alter the existing climatological dynamics, resulting in more frequent and intense cases of extreme weather like droughts, violent storms, floods and blizzards. Desertification would extend to large swathes of territory. These factors, as well as the spread of pests, would cause a dramatic drop in agriculture output. Therefore, food security would be threatened across the globe. Warmer temperatures would also favour the diffusion of diseases and increase energy consumption. It would, therefore, create competition over energy sources. The whole ecosystem would be seriously harmed, both on and at sea, causing severe losses of biodiversity. This would, in turn, result in subsequent chain damages for agriculture and fishing that already suffer from over-exploitation. The ocean level would rise; putting at risk the living conditions of millions of people, who reside along the coasts. All this bears huge economic and social costs in the form of both losses and expenditures to repair or prevent its effects. This should be considered along with other phenomena caused by human activities, notably pollution and over-exploitation of water and soil. The combination of these factors has led some experts to label our current geological epoch as “Anthropocene,” which is a period marked by the human’s capacity to affect the environment to the point of derailing its dynamics out of the natural order. While the term remains debated among scientists, climate change has certainly taken considerable political relevance in the past few decades with the appearance of ecologist movements and parties all over the world. This also holds at the international level, with states making efforts to tackle its effects, as in the case of the 2015 COP21 agreement and other eco-friendly initiatives. However, climate change would also alter the global geopolitical and geoeconomic environment, with tremendous consequences for power distribution and international security. The whole of mankind is set to be harmed by climate change In general terms, the whole of mankind is set to be harmed by climate change. Apart from the direct economic loss in the form of reduced agriculture output, poorer fishing zones and damages to coastal areas caused by rising sea levels, climate change also has significant social and human costs due to environmental degradation, sanitary problems and migratory flows, which, in turn, would bring other expenses to repair and prevent its harmful effects. Yet, there are areas where its impact would be more marked than in others, namely equatorial Africa and South Asia. Both are extremely vulnerable due to their geographic position and are highly populated zones, whose economy is still underdeveloped. As a result, they have to bear all of its negative consequences: GDP loss, food insecurity, water scarcity, violent weather, epidemics, and so on. The consequences would be felt outside these regions, too. In South Asia, the costs of global warming might slow down and even stop India’s rise. Population displacement may result in humanitarian crises and social tension. This is notably the case in Bangladesh, a very poor and densely populated country, extremely exposed to the negative effects of climate change. Existing divergences over the control of the use of water basins might get more serious, for example between India, Pakistan and China over Kashmir, the cornerstone of the Indus river basin, or between India, China and Bangladesh over Ganges and Brahmaputra. The situation is dramatically similar in equatorial Africa. The deleterious consequences of climate change may compromise any hope of economic development and condemn the continent to poverty and perpetual conflict. As a matter of fact, fighting would result from increasing resource scarcity, notably of food and water, and, thus, make the situation along the conflict belt that crosses from Somalia to Nigeria even more troublesome. This is what could soon happen in Ethiopia, where the effects of climate change exacerbate economic and ethnic divides. War could also take a state-to-state dimension as it may break out over the control of rivers like the Niger, Congo or the Nile. With regard to the Nile river, some tensions already exist between Egypt and Ethiopia over its use, and a future water war is a real possibility. Finally, this catastrophic situation will push more and more people to displace, and thus, amplify an already serious humanitarian crisis. Many would try to reach Europe; perpetuating and worsening the migratory crisis it is facing along with all social and political consequences. Resultantly, global warming has global-scale consequences that would affect virtually any domain of human life. But, in general, it can be said that it puts our security at risk, be it economic alimentary, sanitary, physical or of any other type. Scientists have repeatedly raised the alarms over its deleterious effects, but up to now the actual effort to counter it is frankly quite insufficient. Since it appears that avoiding its impact is impossible and that we can, at best, limit its consequences, the best thing we can do is to foresee and understand them. We should prepare ourselves for the world, which would inevitably emerge from climate change. The writer is a biotechnologist and a columnist