The Future of the Global Environment:
A Model-based Analysis Supporting UNEP's
First Global Environment Outlook
Inequality increases in a wealthier and healthier world
In the Conventional Development scenario analyzed in this report, global per capita income increases by 50% and 100%, and life expectancy by 5% and 8%, by 2015 and 2050, respectively. However, inequalities in income between regions become larger in the scenario up to 2015, after which the gap begins to narrow. In some of the poorest regions the demographic transition stagnates and health problems persist.
Environmental pressures build up
Growth in consumption and production exceeds gains from improvements in productivity. In the scenario, energy efficiency is projected to increase by a factor of 1.2 by 2015 and 1.8 by 2050. At the same time, total demand for energy increases by a factor of 1.8 by 2015 and 2.6 by 2050. Agricultural efficiency is projected to increase by a factor of 1.2 by 2015 and 1.4 by 2050. At the same time, total food demand increases by a factor of 1.5 by 2015 and 2.0 by 2050. However, the regional differences in environemtal pressure are great.
Renewable resources at risk of depletion
While depletion of exhaustible resources in the seventies was considered as a major threat to development, integrated assessment based on the Conventional Development scenario suggests that the degradation of renewable resources such as water, land and forests now creates risks that are much more urgent. This may increasingly hinder development on local and regional scales. In the scenario, social and economic capital seems to increase globally, while natural capital is being depleted.
Climate goals are not being achieved
Interacting biogeochemical cycles are increasingly disturbed by human activities. For example, the current commitments of the Climate Convention are insufficient to stabilize atmospheric concentrations in the coming century. Emissions of greenhouse gases from developing regions, notably Asia, will grow rapidly, leading to a 50% increase in 1990 of global carbon dioxide emissions by 2015, and more than a doubling by 2050. Consequently, in addition to increased preventive efforts to control emissions, preparing for adaptation to projected climate impacts becomes urgent. This is particularly true for areas vulnerable to climate impacts in developing regions in low latitudes. Another example is acidification, becoming more important in developing regions with vulnerable soils and accelerating economic development.
Can a 'second' world be fed ?
The key challenge for the world’s agricultural sector will be how to feed double the present population by 2050. Increasing demand for animal products will further boost total agricultural demands. Theoretically, increasing productivity, extending agricultural land and reversing land degradation can provide sufficient food on a global scale. Achieving this and ensuring the adequate distribution of food pose a formidable challenge. Regions such as Asia, West Asia and Africa are projected as being able to increase their food imports, enlarging the scale of agricultural trade significantly.
A serious threat to development by water scarcity confirmed
In many regions, water demand from industry and households is in increasing competition with water for agricultural production. Preliminary global analysis at the catchment level confirms that water scarcity is affecting increasingly large areas, particularly in West Asia and Africa. This may lead to serious security problems, conflicts and large-scale migration. Integrated water management at the riverbasin level and adequate water pricing form the key to alleviating these pressures.
Further conversion of natural lands appears inevitable
In the Conventional Development scenario, agricultural land increases from one-third to almost one-half of the earth's land mass by 2050. This increase is concentrated in tropical and subtropical zones. The remaining natural areas are formed to a large extent by mountainous, boreal, subpolar, arid and semi-arid lands, which are less suitable for human settlement. Simultaneously, these remaining natural areas will be under increasing pressure from population growth, economic development and associated environmental stresses such as climate change. Consequently, biodiversity will be severly affected in the scenario, both in terms of quantity and quality.
Environmental degradation may threaten global health in the loing
In the Conventional Development scenario, life expectancy increases worldwide, up to 70 years. Morbidity declines drastically, especially in developing countries. Expected improvements in income, education, nutrition and water supply will stimulate the decline in fertility needed to stabilize the global population, but how much and how fast is by no means certain. Unfortunately, in many areas (notably, Sub-saharan Africa and many urbanized areas) environment-related health problems will persist or be aggravated. Also, in the long term, an increased population, older in composition and more demanding, will further increase environmental pressures and is likely to undermine its own resource base, which may eventually threaten global health. In this context, increased environmental protection, especially in developing countries, will be essential in the prevention of an increase of disease.
Environmental transitions needed and, in some cases, already
With current technology - where appropriately coupled to behaviourial changes - major progress can be made to reverse the negative developments outlined above and accelerate transitions towards the sustainable use of energy, raw materials, land and water. While the onset of these transitions can be discerned, adequate social, economic and institutional conditions have to be met for realizing these transitions in working towards the Agenda 21 goals.
Linking issues and boosting efficiency in a comprehensive
To promote transitions, linking of issues provides new options for joint gains by the different actors implicated. Many environmental problems can be addressed by focusing efforts on integrated energy and agriculture policies rather than on single-issue policies. Just to keep pressures at current levels, resource efficiencies would have to increase by a factor of 4 to 5 globally by 2050. To reduce pressures towards sustainable levels and re-allocate available resources more equitably, this factor on a regional level may have to be high as 20.
Impact of enhanced policies would be large
Technically, there is much room for mitigating future increases in pollution, resource use and pressure on natural areas. That is: if best available technology could be applied to all new investments, the projected environmental impacts would be much less severe. More structural changes in production and consumption patterns - such as a shift to renewable energy resources and a change of diets - would give humankind even more space. Obviously, this will require broad access to capital and knowledge, and most of all it requires the political determination to make the world a sustainable one.
Integrated assessment: not a solution but a framwork for analysis and
The integrated assessment in this report is based on a quantitative systematic framework for analyzing future global and regional developments, and their interlinkages. However, this assessement is based on a limited set of methodologies and only one scenario depicting neither the most probable nor the most desirable future. To cover regional and disciplinary insights, as well as scientific uncertainties, more comprehensively than possible in this contribution to the first Global Environment Outlook and to focus more on communication between stakeholders and scientists, future analyses should make use of a wider set of methodologies, sensitivity analyses a and scenarios.