Climate change and its effects are observable also in the Netherlands. To date the effects are still limited in magnitude. This might change in the coming decades. Present trends in, for example, sea level rise and land subsidence may accelerate, leading to serious problems in the second half of the 21st century, especially in the lower-lying regions. These form the main conclusions documented in the Netherlands Environmental Assessment Agency recent report, ‘Effects of climate change in the Netherlands’.
The changing climate in the Netherlands is seen in, for example, the rising sea level, the increase in discharge of rivers and the response of nature to temperature changes. Although the observed effects in the Netherlands are limited without having led to serious problems for the country, climate change and its effects are expected to accelerate over the next few decades and persist for a considerable length of time.
The second half of the century may see serious problems arising from climate change, in particular in the low-lying areas of the country. A sea level rise of several to many metres is expected in the very long term (a few hundred years). It is questionable whether conventional techniques can be used to maintain the current level of safety. Greater effort will also be required to uphold this safety level due to the additional problems of possible increase in discharge from the rivers Rhine and Meuse and further land subsidence.
The average temperature will almost certainly further increase (1 to 6°C in 100 years). Dry and extremely warm summers (as in 2003) will be more frequent; the probability of extremely cold winters will decrease, although the famous 'Eleven Cities' skating tour may take place occasionally. Heavy rainfalls may also increase in frequency.
River discharge is likely to increase considerably due to more extreme temperatures and precipitation events. As a result, safety will be at stake and river discharges excessive in the low-lying regions in the Netherlands by the end of the century.
The rate at which the temperature rises will probably be too high to enable many species to adapt or migrate. Several plant and animal species are threatened with extinction in the Netherlands, whereas new species will settle if they can migrate quickly enough. The net effect will probably be a decrease in species diversity in the Netherlands.
The agricultural and tourism sectors will undergo changes that could be both positive and negative from an economic point of view. This will depend partly on developments elsewhere in Europe. There are signs that agricultural damage risks (water logging, droughts and insects) are increasing. Cooling-water problems and limitations on navigation (as in the summer of 2003) will increase if water management does not improve.
Temperature rise caused by climate change may have a direct negative influence on human health in the Netherlands. Possible effects of climate change are: problems due to heat stress, an increasing spread of Lyme disease, poor air quality (summer smog) and an increase in allergies. Risk groups in the population (such as the elderly, children or people with asthma) could experience greater effects (e.g. a greater disease burden).
To respond adequately to these projected influences, climate change has, to a certain extent, already been taken into account in various policies in the Netherlands. Water management policy, for example, now seriously considers climate change by taking technical and spatial planning measures. Technical measures include raising the height of dykes, expanding the capacity of pumping stations and intensifying beach nourishment to maintain sand levels along the coast. Spatial planning measures include accommodating flood storage areas.