State of the Planet

News from the Columbia Climate School


A Faustian Choice: Population and Environment

Malian women working on vulnerable barren lands near Timbuktu.

By Jyotsna Puri

If all mankind were to disappear, the world would regenerate back to the rich state of equilibrium that existed ten thousand years ago. If insects were to vanish, the environment would collapse into chaos. E.O. Wilson (1929 – )

In October 2009, in a seminal article in Nature, a group of scientists pointed out that three of nine subsystems that constitute planetary boundaries have transgressed them. These three subsystems include rate of biodiversity loss, climate change and the nitrogen cycle. Other subsystems are under pressure.

Population growth is a key contributor to these pressures. In Rio+20 discussions, implications of population growth have become shrouded in platitudes. It is important that discussions on planetary limits clearly lay out possible strategies that can alleviate these pressures.

World population will reach 7 billion this year, 9.3 billion by 2050. This is not expected to reverse: Global life expectancy has risen from 47 years (in 1950-55) to 68 (2005-10). Fertility rates are showing a declining trend in almost all countries (although rates vary broadly).  Globally, crude birth rates fell from 37 to 20 per thousand and total fertility (children per woman) fell from 4.92 to 2.57 during the same period.

Population: A challenge and an opportunity. Although couples may be having fewer children, the number of births is large. This surge in young population can be a security concern (the ‘youth bulge’) but also be a window of opportunity, (the ‘demographic dividend’), since it reduces dependency ratios.

Most of the world’s population lives in developing regions, especially in Asia. It is here that younger populations are apparent whereas developed countries show an aging population.  Fertility decline between 1950-55 and 2005-10 was much greater in developing countries (from 6 to 2.7) than in developed countries (2.8 to 1.64).

Urbanization: Urban population is also on the rise. In 1950, less than one-third (29%) of the world population lived in urban areas. By 2010, the numbers had soared and half the world’s population lived in urban areas. . In Asia and Africa, 40% of the population lives in urban areas and growth rates remain high.

Areas otherwise vulnerable to climate change are recording perilously large increases: Urban population in dry lands is estimated to increase from 967 million (45%) in 2000 to 1,590 million (55%) in 2025. Similarly, coastal zones represent 2% of the earth’s land but house 14% of the total world population and 23% of the urban population of the world. Some 18% of the world’s population occupies low-elevation coastal zones (areas between the tidal line and 10m above sea level), frequently in agglomerations of 1 million inhabitants or more.

Policy: Sustainable development strategies must address the question of population pressures and alleviating them. Decoupling or disengaging economic growth from resource use is key. Two thrusts are necessary:

First, addressing the ‘energy efficiency gap’: The energy efficiency gap is the failure of consumers and industry to invest in energy efficient technologies despite the fact that such investment will yield favorable economic returns purely from energy costs, even without accounting for environmental benefits. One key factor is the lack of understanding of cost and energy impacts of commonly used technologies.

Second, altering current consumption patterns: The global use of plastics, food consumption and automobile use are showing worrisome patterns.

Global use of plastics has more than doubled between 1990 and 2009. One-fourth of this production occurs in Europe and one of the most dramatic consequences of this is the ‘Great Pacific Garbage Patch,’ a large area in the North Pacific ocean containing huge amounts of plastic waste systemically infecting the ocean food chain.

Meat production in its current form takes a heavy toll on land, water and nutrients. It is predicted that by 2020 over 60% of meat and milk consumption will take place in the developing world and the production of beef, meat, poultry and pork and milk will at least double from 1993 levels. Grain crop farming, dairy farming, and cattle farming are the largest contributors to the diminishing quality of water indicators such as eutrophication and acidification.

Automobile use has grown exponentially. In 1970 there were 200 million automobiles globally. In 2006, the number had more than quadrupled to over 850 million. This is expected to further double in the next 20 years. Air quality and crowding in cities will further worsen if this is not halted.

Differentiated and adaptive policy: The impact of population growth is highly concentrated in some parts of the world and this will create novel and potentially dangerous pressures.  Differentiated and focused strategies are required.

Differentiated policy: Carbon dioxide emission rates vary markedly between developed countries and developing countries.  Per person per year emissions in high income countries in 2007 were 12.5 tons. In middle income countries this was 2.4 tons. In least developed countries, this was 0.28 tons. China is now the largest emitter of GHGs per year although it remains behind the US and Japan in terms of per capita emissions.

In least developed countries, though fertility rates for women have fallen from 6.54 children per woman, to 4.41 these remain high. The difference in age structures has some environmental consequences that are less recognized. A recent paper on emissions in 25 OECD countries shows that societies with a higher proportion of elderly (65 years of age and more) tended to emit more sulphur dioxide (although, cohorts that had a larger population born after 1960, tended to emit less).

Target the household: In the developed world, households are smaller in size but increasing in number. In urban China, an increase in the number of (smaller) households is matched by a concomitant increase in the number of appliances per capita and escalated electricity consumption.

Bring energy to the poor via increased energy efficiency and increased use of renewable energy. The largest causal factor for increased emissions in 2050 will be the increase in population. Although the causality is complex, in some studies, improving energy efficiencies and alternative energy show that world’s population could be cut in 2050 by as much as 30% from a potential of about 10 billion. Most of this is a result of improved human development indicators associated with better energy access.

Focus on youth: Policies should take advantage of the demographic dividend in countries. A study by Collier (2006) suggests that countries that have 10 percentage points more of its youth in schools cuts its risk of being in conflict by 4 percentage points.  Similarly, in 1994 Washington-based ICRW conducted a survey of more than 200 programs working with adolescents. Active participation by adolescents in all stages of program design and implementation while ensuring dialogue, meant a higher likelihood of success for most adolescent targeted strategies (Esim et al. 2001).

Conclusion: Differentiated and focused policies are required. The better the living conditions, the smaller the family size. Change is possible via policies that address consumption patterns, differential urbanization rates and women’s rights and sexual and reproductive health. Tailoring public programs such as micro-credit to youth, vocational training and employment creation through green jobs is critical.

Cited studies:

Rockstrom et al. “A Safe Operating space for Humanity,” Nature 461, 472-475, September 2009.

Collier, P “Economic causes of Civil Conflict and their Implications for Policy”, Oxford University, April 2006.

Esim, S., A. Malhotra, S. Mathur, G. Duron, C. Johnson-Welch “Making it Work: Linking Youth Reproductive Health and Livelihoods,” ICRW, 2001.

Dr. Puri is currently the deputy executive director of the International Initiative of Impact Evaluation (3ie). Previously as green economy policy adviser at UNEP she has provided technical and strategic advice to governments and engaged in international dialogues for evidence based equitable, green policy transitions. She has been associate research scientist at the Earth Institute, Columbia University, New York and adjunct faculty at the School of International and Public Affairs (SIPA), Columbia University. Jo is the lead author of a book on measuring and interpreting monitoring and evaluation indicators prepared for the Human Development Report Office (UNDP). She led the publication of a synthesis report on Forests in a Green Economy published by UNEP. She is also contributing author and reviewer for the Green Economy Report published by UNEP and co-author of a book examining implications of Joint Implementation of Climate Change commitments for developing countries.

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