Ask engineers and they’ll say there is an engineering solution to any problem. With respect to climate change and geoengineering that’s hotly debated, with respect to overpopulation it’s a novelty.

Today the UK-based Institution of Mechanical Engineers presented a report called ‘Population: one planet, too many people?’ (PDF), backed by research of 70 involved engineers, issuing several engineering solutions that will have to be ‘urgently implemented’ to prevent this Century’s 2.5 billion extra people from ‘crushing earth’s resources’.

Today we’ll start with the quantitative demographic projections the report – in a somewhat random fashion – presents. Most are not based on own research, but on the medium variant of the UN World Population Prospects (2008 Revision):

World, historic

• 1800: 1 billion
• 1950: 2.5 billion
• 2010: 6.9 billion

World, projected

• 2050-2100, medium variant: peak at 9.4 billion
• Uncertainty (low & high variant) for 2050 between 8 and 10.5 billion, 2100 5.1 and 14.2 billion
• All 21^st Century growth is accounted for by the South: Africa, Asia and Latin America. The latter two are forecast to peak in the second half of the Century, Africa is not

Europe (UK)

• Over the course of the Century the European population is forecast to decline by 20 percent, from 0.73 billion to 0.59 billion
• In 2050 in the UK 23 percent of the population will be over the age of 65
• In 2050 in the UK 34 percent of the population will be under the age of 30

Africa (Nigeria)

• Population growth in Africa is by far the fastest. The African population growth is expected to be around 150 percent*, over the period 2010-2100
• Today 1 billion people live in Africa. This is forecast to increase to 2.5 billion
• 50 percent of African population will settle in cities [Recently we reported on a different UN urbanisation outlook for Africa, stating by 2050 60% will live in the cities – tripling urban population over just 40 years.]
• In 2050 Nigeria will have more than half its population (53 percent) under age 30
• Nigerian population will increase from 158 to 338 million
• Some sub-Saharan nations’ populations are expected to triple or quadruple
• (*This projected African population growth includes AIDS mortality)

Asia (China)

• Asia, already home to half the world’s population, will see a further population growth of 25 percent by 2065
• Chinese population will decline from 1.35 to 1.20 billion people [we recently reported on another Chinese population projection, expecting an increase to 1.4 within a decade]
• India’s population will increase from 1.21 to 1.54 billion people
• China is forecast to have major problems with water supply. The country already has 20 percent of the world population, compared to just 7 percent of freshwater resources. Currently in populated areas 90 percent of Northern China’s aquifers are polluted.

Urbanisation

• The urban population will increase from 3.3 billion in 2007 to 6.4 billion in 2050
• In 2025 the world will have 29 ‘mega-cities’ – with over 10 million inhabitants
• By the end of the Century 75 percent of world population will live in urban settlements

Water

• In 2030 water consumption will have increased by 30 percent, due to increased demand for drinking water, industrial water and increased agricultural water use (70%)
• Industrial water use in Asia will grow by 50 percent over that same period

Food

• In 2050 agricultural demand will have increased by 100 percent, due to population growth and changing dietary habits, including an increase of meat consumption.

Energy

• Energy demand will double (this is the IEA figure) towards 2050 (which means carbon intensity has to at least decline by 75% as G8 and UN climate mitigation ambition requires a GHG reduction of at least 50% between 1990 and 2050).

Tomorrow we’ll go through the second part of the report, ‘What needs to change,’ pages 40-42. Here the authors present the engineering solutions to having over 9 billion people share one planet’s resources. Tip of the veil: engineers do not suggest actual demographic solutions. Again, we cannot resist pointing to the CO2 analogy.

© Rolf Schuttenhelm | www.bitsofscience.org