Water and Biodiversity: The North-South Asymmetry Becomes the Real Battleground

As COP17 of the Convention on Biological Diversity approaches, scheduled from 19 to 30 October 2026 in Yerevan, the water question is ceasing to be a technical file and becoming a terrain of confrontation between states over the allocation of conservation costs. The most intense El Niño episode ever recorded is simultaneously striking agricultural systems and water networks with highly unequal absorptive capacities, while the chemical regulation of forever chemicals advances in a decentralised fashion, driven by local jurisdictions and litigation rather than by a unified framework. The physical constraint and the regulatory constraint are converging, yet the means of responding to them diverge profoundly according to levels of development.

This divergence constitutes the structuring dynamic of the month. Where developed countries have operators capable of managing scarcity through administrative restriction and regulators setting binding thresholds, developing countries accumulate infrastructure deficits, diffuse pollution and an absence of dedicated financing. The Yerevan negotiation crystallises this asymmetry around a simple question: who pays for remediation and prevention? For a sector executive, the stakes are not only climatic, they are financial and legal, because the bill for inaction and compliance is now materialising in the form of quantified liabilities.

One Climate Shock, Unequal Response Capacities

The ongoing El Niño episode has matched its historical record, with the temperature anomaly in the Niño 3.4 monitoring zone reaching 3.07°C as of 19 September 2026, equalling the level observed in 2015-2016. This single shock produces effects that reveal, rather than level, the resilience gaps between territories. The nature of the responses speaks volumes about available means. In India, the Ministry of Agriculture on 28 September called on Maharashtra and Karnataka to urgently reorient their rabi-season crops towards less water-intensive varieties such as pulses and oilseeds. In the United Kingdom, South East Water Ltd. applied on 2 October for administrative authorisation to restrict non-essential water uses in Sussex. In both cases, the state or operator holds a lever of arbitration, whether administrative or regulatory.

The situation deteriorates differently where infrastructure is lacking. In Sudan, the El Niño-linked drought combines with armed conflict to amplify the risk of famine in Darfur and Kordofan. At Lake Chad, climate disruption and pollution are suffocating fishing and agriculture, driving up the cost of living. The contrast is stark: the same physical hazard translates into a planned agronomic adjustment on one side and a direct food threat on the other. This inequality of capacity is not incidental; it underpins the claim advanced at Yerevan.

Yerevan, or the Contested Sharing of Conservation Costs

COP17 opens on an acknowledgement of failure: nearly all of the conservation targets of the Global Biodiversity Framework are off track. Against this backdrop, South Africa has announced that it will advocate an action plan focused on mobilising substantial financial resources for developing countries. South Africa is demanding adequate financing for developing countries and a practical implementation plan.

This dispute is not abstract. It pits two conceptions of financing environmental remediation against one another, and it replays itself, in mirror image, on the global plastic pollution treaty, mired by intense lobbying from the petrochemical industry. The data published this month give the measure of the stakes for the countries demanding a resource transfer. SkyTruth's satellite analysis establishes that hydrocarbon slicks covered an average of 1.58 million square kilometres of ocean per year between 2023 and 2025, 81% of which was attributable to maritime traffic. Microplastics now account for up to a quarter of the plastic flux carried from rivers to oceans, and 96% of this pollution originates from the waterways of developing countries, for want of waste-treatment infrastructure. Pollution concentrates precisely where the means to treat it are most lacking, which directly feeds the argument for financing without which conservation remains out of reach.

The Bill, a Lever of Pressure and a Risk for Industrial Players

What is changing, for industrial players as for local authorities, is that the environmental cost is now quantified in payable liabilities. The regulation of forever chemicals advances in a decentralised fashion, driven by local litigation as the 31 December 2026 deadline on PFAS in drinking water approaches. In Bavaria, the municipality of Burghausen resolved in council to bring an action against PFAS manufacturers, demanding €1 million for the management of 50,000 tonnes of polluted soil and preparing claims that could reach €100 million. In France, a coalition bringing together Générations futures, Notre affaire à tous and ClientEarth issued a formal notice to the SEB group on 8 October to obtain a risk mapping and a timetable for phasing out PFAS.

This pressure rests on data that establish contamination as an accepted fact: 60% of eggs analysed in France contained PFAS, with a quarter of the sample exceeding regulatory thresholds, and in Austria the concentration of trifluoroacetic acid in groundwater has doubled nationally, pointing to intensive agriculture. The financial burden of historical remediation is just as tangible: in Haute-Corse, arsenic pollution from the former Matra mine is forcing a drinking-water network rehabilitation project estimated at €3.3 million, increased by €1 million owing to the presence of asbestos. Faced with this rising cost, plastic producers spent €2.5 million in 2025 to block source-reduction legislation in France, a defensive measure that confirms the arbitration has become financial before being technical.

In Brief

• The Colorado River basin is undergoing an acute crisis, with the farming town of Palisade seeking emergency solutions to preserve its fruit production.
• A Kelvin wave generated by El Niño threatens to raise sea levels by half a foot along the California coast.
• In South Africa, the official Green Drop 2025 report confirms the collapse of wastewater treatment across nearly all metropolitan areas between 2021 and 2024, with a risk of supply breakdown in Ermelo.
• In Brittany, the de-listing of municipalities from the roster of nitrate-vulnerable zones drew more than 700 demonstrators in Finistère on 20 September.

To Watch

• 19 to 30 October 2026: COP17 of the Convention on Biological Diversity in Yerevan, centred on the implementation of the 2030 conservation targets and biodiversity financing.

Key Takeaways

• The October 2026 Yerevan COP17 crystallises the North-South asymmetry over conservation financing, as nearly all biodiversity targets remain unreachable.
• A single record-breaking El Niño shock produces planned agronomic adjustments in the North and famine threats in Sudan, revealing profoundly unequal resilience capacities.
• The decentralised regulation of PFAS is transforming environmental cost into payable liabilities, exposing industrial players and local authorities to litigation quantified in millions of euros.

Photo: Harsh Mangalam / Unsplash