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Heavy shower, Ecomare

Climate

Climate is the average weather situation calculated over a long period of time, usually thirty years. Climate fluctuations are more rapid changes which often occur regularly. True climate changes revolve around a much larger time scale. The rhythm of the glacial periods is counted in terms of tens of thousands of years. The transition from the last ice age to a warmer period has been occurring during the past 10,000 years. A more recent part of the present warming up of the earth can be attributed to the greenhouse effect. The relationship between nature phenomena and human influence of the climate is important for a good understanding of the present climate change. Many studies are being performed in this field.

  • Instability

    Even though the last major glacial period ended 10,000 years ago, it doesn't mean that the climate has been stable since then. The differences are now on a very different level; during the Ice Age, our environment was a tundra, the sea level was 30 meters lower and the bottom of the North Sea was exposed. Since the Ice Age ended, there have been various periods of warm and cold, usually several centuries long. There were times when storms, floods and the sea had major influence, as well as quieter centuries in which the sea played a lesser role. Up till around 1430, the average temperature was higher than today, while between 1430 and around 1800 it was colder. One refers to that period as a minor Ice Age.

  • Recent climate developments

    The Royal Netherlands Meteorological Institute (KNMI) regularly calculates the effects of the climate change on the Dutch situation. The following predictions were made in 2006: the temperature will rise 2 to 5 degrees Celsius in the coming one hundred years; there will be more precipitation in the winter while the summers will be dryer; the extreme amounts of precipitation will increase, in other words, lots of rain in a short period of time; the sea level will rise 15 to 35 centimeters by 2050 and 35 to 85 centimeters by 2100. The KNMI reported in 2008 that the average temperature in Western Europe is increasing twice as fast as the rest of the world.

  • Warming up of the North Sea

    Between 1990 and 2000, the temperature of the water in the North Sea was more than 1 degree higher than the average over the previous 30 years. One of the many effects was a sharp decline in the stock of young cod. The North Sea is the southern boundary for the distribution area of cod. This fish species is not found in warmer waters and now that the North Sea is warming up, the number of young is declining. This warming up is possibly due to the greenhouse effect.

  • Influence of climate change on flora and fauna

    Climate change has a tremendous effect on flora and fauna, both directly as well as indirectly. Oceans and coastal seas are also growing warmer due to changes in sea currents and temperature increases in the air, partially caused by the greenhouse effect. In addition, stable weather patterns are being replaced by periods of long droughts or extreme weather conditions. According to a report by the United Nations Environment Programme (UNEP) in 2008, climate change is a threat for the coastal infrastructure, food and water supplies and human health throughout the world. The greatest impact of the climate changes is concentrated in 10 to 15% of the oceans, with the greatest pressure in the areas with the most valuable fishing grounds.
    The UNEP report stated that fish supplies, which were already decreasing due to overfishing, are being threatened worldwide by climate change caused by the discharge of greenhouse gasses such as CO2. The excessive CO2 causes a rise in the degree of acidity in seawater, influencing shellfish and plankton, important links in the food pyramid. High surface water temperatures threaten up to 80% of the coral reefs, which serve as nursuries for fish.
    For the Netherlands in theory, this global warming means that land species from southern regions will survive better, while species from northern territories that prefer cooler circumstances will become threatened or disappear entirely. However, those southern species must have the opportunity to move north, and if there are no ecological connections between regions, many plants and animals will never make it here.
    Research performed by Alterra show that plants are flowering earlier and longer. In addition, they are developing more quickly which is favorable for the agrarian sector that can have more crops. However, it means lots of extra work and costs for nature managers to preserve specific plant communities. Extreme weather conditions mean that nature areas will be disturbed more often, which is unfavorable for rare species, but good for pioneer plants. Plant communities in marram grass dunes react quickly to climate changes which means that warm-weather species will increase and cold-weather species decline. On the other hand, salt marshes react more slowly to climate changes because they are under influence of water. Just like the sea that cools off and warms up more slowly than the air, the water on marshes delays the effect of temperature rises.
    Climate change for birds is a tremendous threat. The International Union for Conservation of Nature IUCN reported in May 2008 that one out of every eight species of birds worldwide is being threatened with extinction and named climate change as an important cause. The organization had a list of 1220 threatened species, including the curlew, which is presently a wide-spread bird species.

  • Did you know that...

    ... models for predicting climate change are calibrated using data going back three centuries, when the thermometer was first invented, but that
    ... using models that have been calibrated with variations in fossil bacteria can provide much more reliable predictions for climate change in the Netherlands. Scientist Jaap Sinninghe Damsté from the NIOZ on Texel and his team can already look back 55 million years.