Syrians and Iraq refugees arrive at Skala Sykamias Lesvos Greece. By Ggia (Own work) [CC BY-SA 4.0], via Wikimedia Commons

Conflict is one response to scarcity of resources. Although a lack of resources is rarely stated as the justification for war, such lack is often an underlying factor. Intercountry and civil war are the most extreme cases, but many lesser forms of conflict — food riots, for example — also can arise when resources are in short supply.Competition for resources resulting from population growth can engender conflict and disruption arising from conflict can in turn reduce access to family planning services. Failed and fragile states do typically have a high birth rate.

Migration is another response. Global migration is at record levels and likely to increase still further as population growth, increased exploitation and climate change increase pressure on resources — particularly fisheries. Increasing unemployment in poorer countries will lead growing numbers to seek a better life abroad.

Migration can bring benefits to both individuals and countries. The individual can gain access new opportunities and the country of origin receives monies sent back to relatives. Some countries rely on such remittances for a large proportion of their income. Likewise, the country of destination obtains skills and labour.

Large-scale and persistent net immigration can result in an imbalance between demand for consumption and sustainable resources. These flows of people represent a humanitarian crisis and put pressure on the sustainability of destination countries. Migrants from poor to rich countries increase their own consumption levels to match the unsustainable levels of their adopted country. Sustained net migration therefore exacerbates global unsustainability.

Countries throughout the world are responding to higher population levels and increasing migration by limiting immigration. No matter what level is set, policies should be applied in a humane and nondiscriminatory manner and the right to asylum of those in fear should be maintained.

We believe the only just and long-term solution to migration pressure is to address its underlying causes in the countries of origin, such as poverty, lack or overexploitation of resources, climate change and conflict. Developed countries have a clear moral responsibility to help with this because they contribute to migratory pressure by being both major consumers of resources from developing countries and the principal source of the causes of climate change.

For countries that have an ecological footprint larger than their carrying capacity, we propose limiting immigration to the extent necessary to allow population numbers to decrease gradually to a sustainable level.

Read more at PopulationMatters.org.