Freshwater resources are of major environmental and economic importance. Their distribution varies widely among and within countries. In arid regions, freshwater resources may at times be limited to the extent that demand for water can be met only by going beyond sustainable use, leading to reductions in terms of freshwater quantities. Freshwater abstractions, particularly for public water supplies, irrigation, industrial processes and cooling of electric power plants, exert a major pressure on water resources, with significant implications for their quantity and quality. Main concerns relate to the inefficient use of water and to its environmental and socio-economic consequences: low river flows, water shortages, salinisation of freshwater bodies in coastal areas, human health problems, loss of wetlands, desertification and reduced food production.

Fisheries make an important contribution to sustainable incomes, employment opportunities and overall food protein intake. On the other hand, overfishing of some species in some areas is threatening stocks with depletion. In certain countries, including at least two OECD countries – Iceland and Japan – fish is the main source of animal protein intake.

Carbon dioxide (CO2) makes up the largest share of greenhouse gases. The addition of man-made greenhouse gases to the atmosphere disturbs the earth’s radiative balance (i.e. the balance between the solar energy that the earth absorbs and radiates back into space). This is leading to an increase in the earth’s surface temperature and to related effects on climate, sea level and world agriculture.

The urgency of the climate change challenge requires a rapid, sustained, and effective transition to lower carbon regional economies. Apart from necessary reduction in greenhouse gases, there is also a need to cut emissions of other pollutants like toxic gases or fine particles that can severely threaten people’s health. Regional and city-level policies have a key role to play in this transition.

The amount of municipal waste generated in a country is related to the rate of urbanisation, the types and patterns of consumption, household revenue and lifestyles. While municipal waste is only one part of total waste generated in each country, its management and treatment often absorbs more than one third of the public sector’s financial efforts to abate and control pollution. The main concerns raised by municipal waste are the potential impact from inappropriate waste management on human health and the environment (soil and water contamination, air quality, land use and landscape).