Planet Earth 2025: A look into the future world of 8 billion humans

Posted: 7 September 2000

Author: Don Hinrichsen & John Rowley

Forecasting the future is asking for trouble. There are too many interacting uncertainties and too many unknowns. The Soviet Union collapsed only months after one eminent historian was predicting its survival long into the 21st century. Indian famines, forecast in the 1960s, have thus far been averted. No one quite knows how fast the earth will warm.

But some factors are more certain than others. Because tomorrow's parents are alive today, population projections for the next quarter century are reasonably predictable, (although the HIV/AIDS pandemic has already had an impact on future forecasts). And related resource challenges are quite visible.

It is now clear that population growth in the next 25 years will not only take place very largely in the less developed countries, but most noticeably in certain regions such as South Asia and sub-Saharan Africa. Pakistan, for example is expected to add another 90 million people to its population of 146 million, while Nigeria could nearly double its numbers from 113 to over 200 million. By contrast, Europe's population will decline over coming decades. Some of the likely consequences are outlined below.

Food forecast As the world's population grows to around 8 billion by 2025 - 35 per cent more than in 1995 - the demand for food and fibre will rise by even more as incomes rise, diets diversify and urban growth accelerates.

© Hartmut Schwarzbach/Still PicturesBut, according to the International Food Policy Research Institute (IFPRI), if present levels of investments in agriculture and social welfare continue, food grain production in some regions of the developing world will only increase by about 1.5 per cent a year over the next two decades. Livestock production, it estimates, will grow faster at 2.7 per cent. But both these levels are much lower than in previous decades and will see population outstripping supply unless there is a big increase in developing country imports.

Even if this happens IFPRI believes that one out of four children under six years of age will still be malnourished in 2020. This is a slight improvement on the situation in 1995 when one out three children were malnourished, but disappointing nevertheless.

But can this really be achieved? Only, IFPRI says, if a big effort is made to improve the capacity of developing countries to enhance the wellbeing of the poor, improve research and extension systems, develop better management and markets and expand international assistance. A big effort will also have to be made to avert the consequences of widespread soil degradation, especially in sub-Saharan Africa and poorly irrigated areas of South Asia.

Liquid of life

One limiting factor in this equation will be the availability of water, without which the blue planet would be a dead and barren wasteland. Today, 31 countries with a collective population of half a billion people are experiencing chronic water shortages. Within 25 years the figure is expected to explode to 3 billion in close to 50 countries, making up more than a third of the world's projected population.

The main reasons for this are population growth and rising consumption. In the last half century, for example, annual demand for water has grown twice as fast as population. Especially worrying is the overpumping of underground waters in countries such as India. According the International Water Management Institute (IWMI), water in India is being pumped at twice the rate it is being replenished by rainfall. The consequence, it speculates, could be a reduction of a quarter in India's harvest, at a time when population there is increasing by 100 million in each decade.

Forest lungs

Another desperate concern is the continued destruction of the earth's forest mantle, which absorbs carbon dioxide and produces oxygen, anchors soils, regulates water flow, modifies climate and provides habitat for countless species of plants and animals.

Each year an area of forest the size of Nepal is cut, bulldozed or razed by fire. It is a process that has destroyed half the world's original forest cover of some 3 billion hectares, mostly in the last 40 years. Only a fifth of what remains is 'frontier forest', undisturbed by human activities, says the World Resources Institute.

One recent survey concludes that population pressure impinges mainly on the forests of Asia. However, according to Population Action International (PAI), the number of people living in countries with critically low levels of forest cover could triple by 2025, rising from 1.7 billion to 4.5 billion or from nearly a third to over a half of the world's people.

Degraded land

Similar projections point to a critical loss of cropland per person, as population increases in some less developed countries. In Ethiopia, for example, where population is projected to grow from 60 to 100 million by 2025, the current 0.12 hectares per person, will be nearly halved. The same factor is a crucial element in migration from the land and the rise in the number of 'environmental refugees', already numbering some 25 million according to the Environmental Exodus report by Myers and Kent.

© Heine Pedersen/Still PicturesThe situation is not helped by the steady degradation of soils in many parts of the planet.

Worldwide, nearly 2 billion hectares of crop and grazing land an area larger than the United States and Mexico combined suffer moderate to severe degradation. To blame are soil erosion, poorly built irrigation systems and other inappropriate farming systems, including the misuse of agricultural chemicals. In the Philippines, for instance, nearly a quarter of cropland is degraded.

According to WRI projections, 40 per cent of the global population - or some 3 billion people - will live in land-short countries by 2025. In these regions there will be fewer than 0.07 hectares of fertile land per person - roughly the size of two tennis courts.

Death by breath

Population growth translates directly into more consumers of energy, more vehicles on the road, more industries and hence more urban pollution. The cumulative effects of population and income growth in the developing world and continued rise in energy consumption in industrialised countries are contributing to pollution and global climate change.

Today, over one billion people suffer from dangerously high air pollution levels, most of them in sprawling cities where industries and power plants have few, if any, pollution controls and where traffic jams are a perpetual feature of urban life. In 20 cities, most of them in the developing world, indoor and outdoor pollution is one of the leading causes of respiratory infections and premature death.

If trends continue, by 2025 close to two billion people will be living in urban areas with elevated levels of air pollution particulates, sulphur and nitrogen dioxides, heavy metals and secondary pollutants such as ozone.

Ocean planet

Today, just over half of humanity, some 3.2 billion people, live and work within 200 kilometres of a sea coast, on just 10 per cent of the earth's land area. A full two-thirds of the world's population are found within 400 km of a coast. Unbridled coastal development and mounting pollution loads pouring into near-shore waters have taken a grim toll on coastal ecosystems.

In the next 25 years, at least another billion people are expected to live within these coastal regions, putting pressure on coastal wetlands, seagrass beds, fisheries and beaches.

Of special concern are the 600,000 square kilometres of coral reefs, more than a quarter of which have already been destroyed. It is estimated that if global warming,coral bleaching and other damage continues, 40 per cent will be gone by the end of this decade and 60 per cent within 25 years. The latest (2001) report by the Global Coral Reef Monitoring Network, says 70 per cent is likely to be gone by the middle of the century

Losing species

One final challenge is the unprecedented rate of habitat loss and species extinction, which could lead to the greatest such event since the mega-extinctions of the Jurassic Period, some 65 million years ago. Some experts have estimated that around 150,000 plant and animal species (or about a quarter of the total) may become extinct within the next 100 years. The projected loss of insects and micro-organisms is incalculable.

Human-induced habitat destruction and the introduction of exotic, or non-native species, has shoved the per cent of birds, mammals, fish, reptiles and amphibians threatened with extinction into double digits. The latest estimate by the World Conservation Union (IUCN)is that over 11,000 species of plants and animals face a high risk of of extinction in the near future. One leading zoologist estimates that current extinction rates are between 1,000 and 10,000 times the historical norm.

Of course, the future is always uncertain, and remains in our own hands to fashion, but the writing is on the wall.