Environmental damage 'will leave $25 trillion a year dent in global economy'

Five separate crises will have a crucial bearing on living standards, and must be tackled together, says UN-backed report

The IPBES report says restoring carbon-rich ecosystems, such as mangroves, has no downside. Photo: IPBES

Environmental damage will cost the world economy up to $25 trillion a year in the decades to come and threaten the health of billions, unless governments address its effects on biodiversity and food production, according to a UN-backed report published on Tuesday.

The Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES), describes its document as the “most ambitious scientific assessment ever undertaken” of the links between five separate crises or “nexus elements” – biodiversity, water, food, health and climate change – that have a crucial bearing on global living standards.

IPBES was established to improve the interface between science and policy on biodiversity and ecosystem services.

The authors of what has been dubbed the “Nexus Report” say that attaching equal importance to all five issues is vital to achieve sustainable development goals, including the 2015 Paris Agreement, under which countries pledged to try to keep global temperature rises to less 1.5ºC above pre-industrial levels.

They warn that addressing the challenges in isolation would worsen the global picture.

The report’s co-author, Prof Paula Harrison of the UK Centre for Ecology and Hydrology research institute, said the message to policymakers was that “you can’t sustainably tackle any of them – food production, climate change or biodiversity loss – without considering the others”. She added: “We have to stop thinking about these as single issues.”

One example is how a “food first” isolated approach that targets hunger risks more climate damage. Boosting food production at any cost might feed more people in the short term. But too much unsustainable farming will probably hit biodiversity, water supplies and accelerate climate change, says the report.

“We have to move decisions and actions beyond single issues,” said Prof Harrison, adding that considering the interconnection between health and environment could bring dramatic benefits.

She cited new progress in fighting the devastating parasitic disease schistosomiasis – also known as bilharzia – that affects more than 200 million people worldwide, mainly in Africa.

Viewed simply as a health challenge and tackled with medication, the disease tends to recur as people are reinfected.

But an innovative project in rural Senegal has taken a different approach. Researchers have cut water pollution and removed invasive water plants to eliminate the habitat for the snails that host the parasitic worms that carry the disease. This has slashed new infections in children by 32 per cent and provided access to fresh water and new revenue for the local communities.

Another example is the 30 per cent increase in cereal yields and biodiversity achieved in some parts of south-central Niger through farmer-managed natural regeneration of 5 million hectares, using native trees and agroforestry systems.

Prof Harrison's report sets out a road map, adaptable for different regions of the world, that she says allows government to “get the widest benefits across all of our five nexus elements”.

It focuses on sustainable production and consumption, and combines this with conserving and restoring ecosystems, cutting pollution and fighting and adapting to climate change.

The report says examples of practices that tackled the key issues, with few or no downsides, include:

• restoring carbon-rich ecosystems, such as forests, soils and mangroves
• protecting biodiversity to reduce risk of diseases spreading from animals to humans
• improving of land-sea borders
• supporting indigenous food and conservation systems
• encouraging transboundary co-operation over water management

Representatives of the 147 member-states of IPBES approved the report, officially titled The Assessment Report on the Interlinkages Among Biodiversity, Water, Food and Health, in Namibia's capital Windhoek, on Monday.

It is the result of three years of work by 165 leading international experts from 57 countries.

The document lists stark evidence that action is needed, including a 2 to 6 per cent decline in global biodiversity decline per decade in the last 30-50 years. It says that 50 per cent of the global population lives in areas experiencing the steepest declines in biodiversity, water availability and food security, and worst effects from climate change.

The extent of the global climate crisis was underlined when a UN report marking this month's Cop16 summit to address land degradation, drought and desertification in Saudi Arabia warned that a quarter of the world's population faced conditions that “redefine life on Earth”.

Today’s report says that $58 trillion – more than half of global GDP – was generated last year in global sectors significantly or largely dependent on nature.

And its authors estimate an unintended reduction of between $10 and $25 trillion a year in global GDP due to negative impacts that the fossil fuel, agriculture and fisheries sectors have on biodiversity, climate change, water, and health.

“The report underscores the need for diverse knowledge systems, values and governance approaches to effectively tackle today's interconnected global challenges,” said Audrey Azoulay, director general of Unesco, the UN agency promoting co-operation in education, arts, sciences and culture.

A follow-up report from IPBES, titled Transformative Change Assessment will be published on Wednesday, specifically addressing biodiversity loss and the action needed to tackle it. It will call on adoption of measures of wealth, other than GDP, that also take into account public health and sustainability.