Calculation of each nation’s ‘ecological footprint’ is possible through a principal tool of complex analysis and calculation conducted by the Global Footprint Network. This determines the point each year when humans have exceeded the capacity of land and sea to supply adequate resources for survival, as well as to absorb the damage of pollutants, greenhouse gases, resource depletion and other outcomes of unabated consumption. The conversion of resources to waste at a rate faster than waste can be converted back into resources, puts us in global ecological debt or overshoot whereby we deplete the very resources on which human life and biodiversity depend.
In 1961, humans only used around three-quarters of the capacity earth has for generating food, timber, fish and absorption of greenhouse gases, with most countries having more resources than they consumed.
However, through calculations of ecological footprints, it is evident that this is no longer the case, with the planet now sliding into ecological debt earlier and earlier each year with 86% of the world’s population now living in countries where the ecological footprint outstrips what the country’s resources can cope with.
This ecological overspending comes at a cost, evident through deforestation, drought, water scarcity, erosion, biodiversity loss and the accumulation of carbon dioxide in the atmosphere. The demand on nature first exceeded the earth’s yearly ability to meet that demand in 1970 and this fallen shorter each year since. Therefore, the day on which the world has used up the yearly capacity of natural resources has shifted from early October in 2000 to the 19th of August in 2014. It is now estimated that it would take 1.5 earths to produce the renewable natural resources needed to support human requirements.
This is hugely problematic as it puts long-term economic security at risk, with countries with resource deficits and low incomes becoming exceptionally vulnerable. Countries would derive long-term financial gains from addressing the direct impacts of resource dependence before they become significant economic stress, yet this is primarily only possible for high-income countries.
The concept of ecological debt seeks to highlight the international inequalities and lack of political power of poorer regions and nations through raising both political and ethical questions concerning debt calculation. Through this, ‘debt’ arises from exports of raw materials and other products from relatively poor countries or regions, sold at prices which lack compensation for local or global externalities. Furthermore, richer countries or regions tend to make disproportionate use of environmental space or services without payment. There is thus much support for ecological debt payment through argument that wealthier nations or companies must help poorer nations since the environment is a collective good damaged bywith huge trade imbalances and disproportionate use.
Implementation of ecological debt calculation and payment might be more successful through a more circular economy which would consider the full life cycle of finite resources and seek to develop more self-sustaining methods of production and services. This would support poorer or developing countries which tend to shoulder a disproportionately larger burden of the social, economic and environmental costs of ecological overshoot and subsequent climatic changes, not least because they are least able to pay for protection and least able to deal with its affects, which are largely attributable to richer nations.
A focus on valuation of natural capital seeks to embed the value of nature within the economy. Putting the environment at the heart of the economy may be what it takes to ensure sustainable growth as once nature is viewed as a set of assets, it can be valued in economic calculations. This would demand more consideration when extracting and using resources and would be particularly effective if following the asset-based sustainable capital rule. This proposes that the aggregate level of natural capital should not decline, and demands that any depletion to renewable resources should be replaced with other renewable capital at least as good as the original resource to ensure no net loss. Further extension of this includes non-renewable resources. This would require practical policies of compensation for any physical damage within the aggregate, environmental taxes, subsidies and permits, and the provision of natural capital public goods, since the private sector has little incentive to provide them.
There are objections to ecological debt concerning its monetisation of nature’s services. This requires monetary estimations of the value of the environment, presenting many challenges because of ethical barriers, uncertainties, incomparable impacts, limited substitutability between natural and manmade capital, and arbitrariness of the discount rate.
However, it is evidently theoretically possible to put a value on ecological debt and these calculations allow us to identify the present ecological debt of various nations globally.
In Africa, 30 countries are in deficit of their ecological biocapacity. Burundi, Djibouti, South Africa, Swaziland, Tunisia, Kenya and Uganda have a particularly great deficit, either because of high per capita carbon emissions, or population pressure and demand for crop and grazing land. These countries are using up at least twice as much natural resources as their countries are able to regenerate in a year. This is where ecological collapse would occur first, particularly in the lower income countries that have lower financial capacity to adapt to the new harsh economic reality.
However, there are 22 African countries with an ecological surplus, which might see an influx of environmental refugees in the coming decades. Those using less than half of their biocapacity, so theoretically able to support an influx of environmental migrants, are Angola, Eritrea and Namibia, which use 30% of biocapacity, and Liberia, Madagascar, Mozambique and Zambia are using 40% of biocapacity.
Looking to the future, if global carbon emissions were to reduce by at least 30%, earth overshoot day could be moved back to the 16th of September 2030, assuming the rest of the footprint would continue to expand at the current rate. However, if business continues as usual, the world would be using resources at a rate equivalent to the biocapacity of two earths by 2030. If this occurs, earth overshoot day would move up to the end of June.
Ecological debt may thus be central to future attempts to push back earth overshoot day, compensate those disproportionately impacted by use exceeding biocapacity, and increase awareness of the environmental impacts of resource extraction.