The temperature is rising. The amount of greenhouse gases is increasing rapidly and the consequences are also great. We mainly focus on the consequences of the greenhouse effect on the climate of the Netherlands. Focusing entirely on the Netherlands is of course very difficult, after all, the greenhouse effect is a global problem
What is the greenhouse effect?
The earth is naturally kept at the right temperature by the greenhouse effect. This is mainly due to the presence of water vapor and carbon dioxide in the atmosphere. The heat that the earth receives from the sun is mainly retained by these gases. If this natural greenhouse effect did not exist, the average worldwide would be much colder than the current global average temperature of about 15 degrees.
However, humans are engaged in changing the composition of the atmosphere on a large scale, including through combustion, deforestation and traffic. As a result, gases such as carbon dioxide are released into the atmosphere. This increases the greenhouse effect and eventually leads to a warmer climate. The amounts of precipitation, wind and clouds can then also change.
The years 1988-2000 were remarkably warm in our country. In those years the winters in particular were very mild; the winter of 1996 was the first to break with that tradition. The warm years are mainly the result of deviating patterns in the large-scale air currents. The higher temperatures in the Netherlands have been largely offset by lower temperatures elsewhere.
Yet the global climate is slowly getting warmer. At the beginning of this century, the global mean temperature rose by about half a degree. This increase is mainly attributed to natural causes, such as an accidental decrease in the number of volcanic eruptions. The temperature has risen more sharply in the last twenty years.
After the eruption of Pinatubo volcano in the Philippines, this trend was temporarily interrupted. The dust cloud that this volcano emitted led to a global temperature drop of about half a degree. In the meantime, this dust has disappeared for a few years and the world mean temperature of 1994 is among the highest since the measurements started in 1861, while 2005 has become the warmest year in the whole series worldwide. The observed global warming is roughly equal to the temperature change that climate models calculate on the basis of the increased greenhouse effect. There are indications that the current warming is at least partly attributable to man-made climate change. The warmer climate of recent decades is also an indication that climate models may well be right and that we are on the way to a climate in which cold periods are becoming rarer and warm periods are normal.
The greenhouse effect in the Netherlands
The consequences of the enhanced greenhouse effect are multifaceted. It is certain that climate change will have a major impact on Dutch spatial planning, agriculture and nature in the coming decades.
Rising sea levels, broader rivers
In January 2004, the Ministry of Transport, Public Works and Water Management announced measures for coastal defenses. A rapid approach to weak links in the coastal defense is necessary. As a result of global warming, a sea level rise of between 20 and 85 centimeters is expected this century. Flatulence from the west is also increasing by ten percent. New knowledge about wave height and wave periods has also made it clear that the Dutch coast will be exposed to greater forces than has always been assumed. The government has now drawn up a plan to combat these dangers.
Rivers will need more space due to the changing climate. The government has therefore investigated the establishment of possible emergency overflow areas in the Ooijpolder and the Rijnstrangen (Gelderland) and the Beersche Overlaat (North Brabant). If the Meuse or Rhine threatens to flood, excess water in these areas could be drained. An independent committee will work this out in consultation with residents and businesses in the area.
A wetter climate
Dutch sewers are increasingly struggling with the wetter climate. Rainwater is mostly discharged via the sewage system. However, if it rains too hard, sewers can no longer handle the amount and some of the content is transferred to ditches. This is especially annoying in agricultural areas, because the cattle often drink from the same ditches. Due to the discharge of untreated sewage water, there is a risk that the animals will contract diseases and infections.
Flooding of the IJsselmeer?
Due to the increased rainfall, the rivers will supply more and more water to the Netherlands. The IJsseldelta in particular, the northwestern area of Kampen and Zwolle can be threatened by high water levels. To prevent flooding, twice as much water will be discharged into the Wadden Sea.
Exotic pests and algae
Climate change is increasing the number of exotic insect pests. Many new species are emerging in the Netherlands. The best-known example of this is the oak processionary caterpillar, which appeared in Brabant in the early 1990s. In the meantime, the caterpillar is also becoming a plague above the major rivers. Other exotic species are also emerging, such as the horse chestnut leaf moth and the black pine cicada. Due to the warming of the climate, the insects can hibernate well. Moreover, there are no natural enemies, so that the species spread quickly.
Aquatic life
Aquatic life is also affected by climate change. In the coming century, the amount of harmful algae off the Dutch coast will grow unprecedentedly as a result of global warming. Eight ‘pest algae’ have been studied, which are unhealthy for humans and animals. Four species can experience a growth spurt due to climate change. An increase in algae means more fish death, because the algae secrete toxins that settle on gills.
In the Netherlands – in close consultation with European partners – additional measures have been taken, such as an increase in energy tax, energy savings in agriculture and industry, making car fuel cleaner, and a reduction in car mobility. Various subsidy programs have been developed for this.
Measures
Governments of many countries, including the Netherlands, recognize the principle that humans are responsible for climate change. International agreements have therefore been made to reduce the emission of greenhouse gases into the atmosphere. In Japan’s Kyoto, almost all governments in the world reached agreements in 1997 describing possible methods for limiting emissions. An important part of the measures to be taken was the introduction of a system of greenhouse gas emission allowance trading.
In Kyoto it was calculated how much greenhouse gases were emitted by various countries in 1990. The list was led by America (36.1 percent), followed by countries in the European Union (24.2 percent), Russia (17.4 percent), Japan (8.5 percent), EU candidate countries (7.4 percent), Canada (3.3 percent) and Australia (2.1 percent). However, the share of Third World countries is not included in these figures. Major polluters such as China and India are therefore (for the time being) excluded from the figures.
Not all countries supported the so-called Kyoto Protocol. Almost all European countries, Japan and Canada supported the protocol in 2001 and 2002, but US President Bush pulled the emergency brake in April 2001. According to the US government, the Protocol contains fundamental errors. Bush, for example, questioned the role of human action in causing global warming. Russia was also delayed for a long time, but now that Russia ratified the Protocol in November 2004, ‘Kyoto’ has been legally valid since February 16, 2005.