Data from 2015 showed that, although extreme poverty had declined significantly over the past two decades, 14 per cent of the population of the developing world was still subsisting on less than $1.25 per day, defined by the UN as an international indicator of poverty. 

The greatest long-term personal contribution that most people can make to sustainability is to refrain from having an unsustainable number of children — as explained in our smaller families webpage.

Background We live in an Age of Migration, with 244 million people, or 3.3 per cent of the world’s population, living outside their country of birth in 2015. 1 Migration, as such, is not new. Studies by paleoanthropologists suggest that, since the earliest times for which we have evidence, our human ancestors and other hominids have migrated. More recently, many significant migrations have been recorded — for example, between 1836 and 1914 more than 30 million.

World population Genetic information suggests that around 70,000 years ago there was a dramatic collapse in the world human population, and it fell to very low numbers.1 Subsequently, numbers recovered and the development of agriculture and settled communities enabled populations to grow.

Availability of clean renewable energy is a critical issue affecting the future of humanity. It is one of the most significant constraints both on the lifestyles and on the number of people that will be sustainable in generations to come.

The future population growth of the world is difficult to predict accurately. A range of projections has been published by organizations such as the United Nations and the US Census Bureau, depending on different assumptions of birth rates and other factors affecting numbers.

Global perspective

Worldwide, 225 million women have an ‘unmet need’ for modern contraception. Having an unmet need is defined as wanting to stop or delay childbearing but not using any method of contraception1. 

Only recently has it been possible directly to measure temperature, rainfall and the other weather variables that make up our climate. H

These two concepts were developed by the Global Footprint Network (GFN) and are quantified as global hectares (gha). They provide a common basis on which to compare the biological capability of the environment to provide food and meet other essential needs, versus the demands placed by human communities on these ecological services.

Responding to ageing populations Populations around the world are ageing as life expectancy increases and as birth rates fall. At present, the increased proportion of elderly people in the population is generally higher in developed countries than in others, but ageing is increasingly becoming a global phenomenon.