Nitrogen also finds its way into the Baltic Sea directly through the air. The main sources of nitrogen deposition are road and marine transport, the fossil fuels used in heating and industry, and agriculture. Nitrogen can travel long distances in the air, and it can have a significant effect when it dissolves into water, as, unlike most types of algae, Cyanobacteria, or blue-green algae, can use it as a nutrient.
Greenhouse gas emissions caused by domestic transport in Finland make up approximately 20% of the country’s greenhouse gas emissions. By reducing our use of cars, and cycling or taking public transport instead, you can lower emissions, as the majority of road traffic emissions are caused by short journeys of only a few kilometres. For long journeys, travelling by train is the most environmentally friendly form of transport.
The Gulf of Finland is one of the most heavily trafficked marine areas. Every year approximately 40,000 vessels travel through the Gulf of Finland, and 6,500 of these are oil tankers. Marine transport creates both airborne and waste water discharges. Airborne emissions come in the form of nitrogen and sulfur oxides, as well as greenhouse gases. Waste water emissions from vessels in the Baltic Sea produce 356 tonnes of nitrogen and 119 tonnes of phosphorus every year. Whilst these numbers are small in comparison to the emissions from agriculture, they occur primarily in the summer when algae are at the peak of their growing period, and the algae can use the nutrients as they are, with no need to wait for them to break down. When you go on a cruise in the Baltic, book with a company that is environmentally responsible.
Energy production and transport emissions also accelerate climate change, which will lead to the predicted rise in temperature and increase in winter precipitation in the Baltic Sea region. Increased winter precipitation will lead to higher nutrient leaching into the sea, which in turn will increase eutrophication even further. An increase in precipitation will also lead to the salinity of the Baltic Sea decreasing, which would be problematic particularly for those species that favour salt water. A rise in the water temperature would probably also lead to an increase in the levels of invasive species, allowing many species that favour warmer waters to settle easily in the Baltic Sea. Milder winters would also have an effect on the extent and thickness of the ice cover. Grey and ringed seals, which breed on the ice, in particular would suffer from the thinning of the ice cover.
Across the world, reduction of environmental hazards in cities, such as urban runoff and air pollution, has been brought about through the use of green roofs. Green roofs are roofs covered with living vegetation, and have many benefits in an urban environment.
In such environments, many surfaces are impervious to water, which means that rainwater places a strain on the drainage network. With green roofs the amount of urban runoff is reduced, as water is absorbed into the vegetation and seedbeds. Green roofs also improve the air quality in cities, as the vegetation filters pollutant particles and gases. Water evaporating from the vegetation cools the air, which helps with the excessive heating of surfaces in urban environments. In addition to this, green roofs make cities more pleasant places to be, and provide a habitat for different species. They attract birds, butterflies, and other insects. Green roofs can also reduce sound problems, as uneven surfaces reflect noise less than the hard surfaces of cities.
The University of Helsinki is carrying out research to find out how green roofs could be adapted and integrated into Finnish town planning and building culture.