The bill for land degradation worldwide could run into the trillions of pounds each year, according to a new study, which estimates the costs of damage to the environment.

The area of degraded land, which has lost nutrients and the capacity to perform its natural functions through deforestation or unsustainable farming practices which have damaged soil health, is on the rise around the world. In a bid to inform policy decision on land-use choices worldwide, experts have assessed the value of so-called ecosystem services (natural functions upon which humans rely) such as clean water provision, crop pollination, nutrient cycling and natural pest control.

Though this approach of ascribing a financial value to natural systems or areas that exist outside the market has been criticised by some, many of whom believe in environmental protection for its own sake, and argue that financial valuations have no place in this field, the dominant view in conservation circles is that this form of cost accounting is the simplest way of explaining the tradeoffs involved in protecting natural resources.  

Researchers from the UN University, working with a number of national and international research institutes, this week released a report in which they estimate the cost of land degradation in terms of the loss of ‘ecosystem service’ functions. They estimate this be between £4.5 trillion and £6.8 trillion each year. This is the equivalent of 10-17 percent of global GDP.

Though the figure may appear astonishingly high, but this is the intention of the mechanism; the idea being that the more a resource is threatened, the higher the cost of further degradation becomes.

According to the findings of the extensive report, which was four years in the making, over half (52%) of the planet’s agricultural land is already classed as degraded.

What is more, the current rate of land degradation could lead to mass migrations as an estimated 50 million people may be forced to seek new homes and livelihoods within 10 years, according to UN University researchers. That many migrants assembled would constitute the world's 28th largest country by population.

The researchers offered recommendations to bring down the cost to humanity, including reforestation, wider adoption of sustainable agricultural practices, and establishing alternative livelihoods such as eco-tourism. They said that effectively addressing land degradation could not only help avert environmental and humanitarian crises, but could also make economic sense (adding trillions of pounds more into the global economy each year).

Agriculture is the easiest area for improvement

Soil is second only to oceans as the planet's largest carbon sink, and agriculture and associated land use changes represent the second largest source of greenhouse gas emissions. Farming is therefore a prime area of focus to reduce the impact of land degradation.

"Adequate management of agricultural and forestry land uses are amongst the lowest-cost actions that can reduce global warming, and most actions are either neutral cost or of positive net profit to society, requiring no substantial capital investment," according to the report.

The researchers said that national studies support their conclusion that the cost of action to prevent land degradation far outweighs the cost of remediation. The report calls on countries to recognise the huge value of improved land management and to honour this in policy decisions

Commenting on the findings, Monique Barbut, Executive Secretary of the UN Convention to Combat Desertification said, "As Oscar Wilde put it once 'people know the price of everything and the value of nothing.' This is certainly true when we look at our land resources - we do not value them. [This] Initiative proves it should be a no-brainer.

“Land degradation eats away at our fertile land. That is our common resource base. It is time to efficiently and cost-effectively harness the land and land-based ecosystems to provide for our needs and secure our livelihoods."

Facts from the report:

• Land cover changes since year 2000 are responsible for half to 75% of the lost ecosystem services value
• The value of lost ecosystem services due to land degradation averages US $43,400 to $72,000 per square km, some US $870 to $1,450 per person, globally each year
• Agricultural investments of US $30 billion per year are needed to feed the world's growing population
• The percentage of Earth's land stricken by serious drought doubled from the 1970s to the early 2000s
• One third of the world is vulnerable to land degradation; one third of Africa is threatened by desertification
• A future focused on a shift to sustainability will see the greatest increase in ecosystem service values and GDP.