November the 15th, 2026 – Croatia should be deeply concerned about the warming of the Adriatic Sea, but what can actually be done about it right now? Quite a lot, as it happens.
The Mediterranean is one of the world’s hot spots when it comes to damaging climate change, and the Adriatic in particular is among the seas where average and extreme surface temperatures are rising the fastest. Nenad Jaric Dauenhaur reports for Index that the surface of the world’s oceans has warmed by about 1 °C since the end of the 19th century. In the southern Adriatic specifically, the warming trend of the upper 20 metres of the sea has, in places, reached about 3 °C per century. The Adriatic is a semi-enclosed sea, and its shallow north is particularly sensitive to warming. But changes are also visible in the depths. A study published this autumn showed that the acceleration of warming of deep waters is particularly pronounced in the southern Adriatic.
The consequences are also felt on land, or in the air. The air in the Mediterranean has been warming faster than the global average since the 1980s. At the beginning of the 2020s the average air temperature in the region was about 1.5 °C higher than in the pre-industrial period. Heat waves are becoming more frequent and more intense, the risk of droughts and fires is rising, and extreme heat increases mortality, especially among the elderly. Droughts in turn reduce water reserves and threaten agriculture.
the limits of coastal protection
Nicolas Entrup, director of international relations at the organisation OceanCare, revealed that the coast can be protected from floods and sea-level rise, which is a matter of adaptation, but that such measures will not stop the main cause, which is warming. “We must do everything to limit its scale, and we can only do that if we reduce emissions faster,” he adds.
extensive economic damage
According to an estimate by the World Bank, damage from climate change in Croatia from 1980 to 2021 averaged around 0.7 percent of GDP annually, with tourism, agriculture and forestry being the most affected. Croatia, Entrup says, can introduce some measures immediately, and can achieve a greater effect if it manages to actually agree on some common rules with its neighbours. This is where OceanCare comes into the picture. OceanCare is a Swiss non-governmental organisation that deals with the protection of marine species, underwater noise, plastic pollution and the impact of fishing on the sea. It has special consultative status with the UN Economic and Social Council, is accredited for UN climate negotiations, and this year co-organised a discussion on the de-carbonisation of the Mediterranean in the European Parliament.
Mediterranean countries agreed in 2025 on a common framework for adaptation to climate change, but emissions in the region, according to OceanCare, continue to rise. Ahead of the UN climate conference COP31, which is being held from 9 to 20 November in Antalya, Turkey, the organisation called on them to draw up a joint emissions reduction plan within the framework of the Barcelona Convention. It would be the first such plan within any of the world’s conventions on regional seas.
According to an analysis by the Basque Centre for Climate Change prepared for OceanCare, if emissions remain at the current level, the Mediterranean will by 2035 already have exhausted its share of the remaining global carbon budget. That budget represents the total amount of CO₂ that the world can still emit while aiming to keep long-term global warming below 2 °C relative to the pre-industrial period. The analysis estimates that from 2030 to 2050 emissions should be reduced by around six percent per year. Earlier cuts would ease the pressure after 2030.
croatia will have the opportunity to make history in 2027, but will it take it?
OceanCare is calling for countries to start reducing emissions immediately, to stop exploration of new oil and gas deposits at sea, and to fairly share the remaining carbon budget. Entrup stresses that Turkey and the countries of North Africa must also participate in the agreement. He sees an opportunity at the meeting of the parties to the Barcelona Convention in Croatia in December 2027. “Croatia will then have the opportunity to make history,” he emphasises.
immediate measures that can be taken in croatia
One measure that states, according to Entrup, could introduce immediately is mandatory slowing of vessels. “Just like when you drive a car, the faster you go, the more fuel you use. When a ship sails more slowly, it emits fewer greenhouse gases and pollutants and creates less underwater noise. Slower sailing also reduces the risk of collisions with endangered whales. Even one or two knots less can significantly reduce emissions if the measure is applied to a large number of ships,” Entrup claims. Limits could differ according to vessel category, while common rules for the entire Mediterranean should ensure equal conditions for all shipowners.
Shipowners must also know which fuels they will be able to count on before investing millions in new ships. The International Maritime Organisation has set a goal of net-zero emissions around 2050, with intermediate targets for 2030 and 2040, but has postponed the adoption of concrete measures. “Nobody wants to risk such an investment if they do not know what conditions will apply in ten or fifteen years,” Entrup says. Among the countries that oppose a faster abandonment of fossil fuels, the USA, Russia and Iran particularly stand out.
are there any good examples?
Colder seas often abound in plankton and fish, especially where the mixing of water brings nutrients from the depths to the surface. Warmer seas can mean less fish and a different composition of catches, Entrup warns.
“Tropical species can displace native ones, and among the newcomers in the eastern Mediterranean there are also poisonous species. Intensive fishing further burdens the sea,” he warns. As an example of a measure that has proven useful, Entrup cites the Jabuka Pit between Croatia and Italy. There, in 2017, certain forms of fishing were restricted in order to allow the recovery of populations of hake, Norway lobster and other species.
“When you protect an area, the fish stocks can recover. Fishermen see that in their nets,” he says. OceanCare is calling for a ban on bottom trawling, starting with protected marine areas. Dragging heavy nets along the bottom damages habitats and consumes a lot of fuel, and the organisation also warns of the possible release of carbon from the sediment.
what could croatia do, and how can the eu remain competitive?
Entrup proposes that Croatia gradually phase out existing oil and gas exploitation at sea and stop issuing new permits. As examples of countries that have stopped new exploration he cites France, Portugal and Spain. OceanCare warns that seismic surveys, among other things, create strong underwater noise that can harm marine animals over a large area, because noise is transmitted more strongly through water than through air. Asked how the EU specifically can remain competitive while the USA wants to expand drilling and Russia relies significantly on energy exports, Entrup replies that it is precisely dependence on fossil fuel imports that endangers Europe and exposes it to price spikes. As examples he cites the Russian war against Ukraine and the war involving Iran. In the transition to sun and wind he sees an opportunity for greater energy security and new jobs.
renewable energy and the plague of data centres
In addition to investment in renewable sources, Entrup also advocates more efficient equipment and incentives for energy saving. “If production from renewable sources grows, but total consumption grows at the same rate, the share of renewables will not increase,” he says.
Asked about plans for a huge data centre in Topusko in Croatia, he said he does not know the details of the project, but that powering it with additional quantities of gas would be contrary to the energy transition. The cost of delaying emissions reductions is already visible, Entrup says, from summer fires in Spain, Greece and France to coastal damage and water shortages that affect agriculture. “We are already feeling the consequences now. What will it be like in ten years if warming continues? We need to act together, as neighbours. We are all in the same boat,” he concluded.
