In recent days, one news story that has dominated the international media was the drowning of a boat of African immigrants in the Italian seas. The uproar at the human tragedy has brought to the fore one key issue that faces mankind: the issue of immigration and migration. This issue is as old as human civilization itself and no single factor has contributed to the rise and fall of civilisations than immigration. Be it the Great Wall of China, constructed by successive Chinese dynasties to protect themselves from invasion by northerners or the collapse of the Roman Empire starting with migration flows of ‘barbarians’, leading to outright invasions, the migration of humans from less privileged areas to prosperous ones and the subsequent shake ups have been at the heart of evolution in human history. So, just when human plight and the immediate causes of migration are talked about, to understand the phenomena one needs to analyse migration in a broader historical and sociological context to better understand what is at stake and why policymakers are responding the way they are.Migration has two broader patterns. First are migrations related to economic activity. These migrations can be classified into international migrations and intra-country migrations in the present political setup. Second are migrations related to climatic change. Interestingly, we are living at a time when both these patterns are ready to play a part in migrations across the globe, remaining the biggest threat to the global order. Economic activity is causing massive migrations across the globe. The west, which enjoyed a competitive advantage emanating from the Industrial Revolution and colonisation, started the process itself by inviting migrants from colonies to act as the labour force. This initiated a process of interaction between the haves and have-nots. Seeing the opportunity in the ‘have-lands’, the have-nots started moving in droves to these places even when labour resources reached a saturation point in developed economies. A similar phenomena happened in the US where the influx of Latin-American immigrants, particularly Mexicans, contributed to the massive influx of low-skilled labour migrants. At another level, a similar phenomena is in play within countries as well where massive migration is taking place from rural areas to cities in developing and under-developed economies. These migrations, even if planned and controlled, are leading to major ecological strains on the urban life of those nations. Now these migrations have reached a point where they are all set to shake the existing order, internationally as well as within nation states. The phenomenon is irreversible but the only thing that can reverse it is income equality. If a sweeper at a restaurant of an international fast food chain in Lahore earns 40 cents while the same sweeper earns $ 10 in the US for the same job, migration flow will continue. This equality is easier to achieve and manage for intra-state migrations than for international migrations. Even for intra-state migration, this equality solution will be a hard sell because of the shortsighted vested interests of the powerful. However, if by some magic wand, humanity manages to tackle the threat of economic migration, the threat of migration will still loom for ecological reasons.And here comes the bigger threat of migrations because of climate and eco-system related issues. Because of the changing climate, rising sea levels and water shortage, many places are fast becoming inhabitable. Ecological pressures caused by rapid urbanisation and population explosion are making matters worse. because of this reason, the migration threat looms and is getting graver. One of the major waves of migration to Karachi was in the aftermath of the 2011 floods. I have been writing for some time that central Punjab has become ecologically unsustainable because of unmanageable population density, lowering of the water table and lack of indigenous energy sources. The same pattern is in play in the northern parts of India. Both areas are sitting on an ecological time bomb and once this bomb explodes, it will open the floodgates of the biggest mass migration in human history, followed by subsequent suffering. This area is not the only area in the world facing such a threat. From Australia to the Americas, from Manchuria to Africa, many are in line. Facing this challenge requires a radical departure from the problem-solving approach deployed thus far. It will require taking on self-centred, short-term, powerful interests driven by greed and inequality. A few may think they can fly to Mars once push comes to shove but, for mankind, departing earth may not be the option. Before the aliens come in full force, we still have time. The author can be reached on twitter at @aalimalik