Based on the most recent results from climate research, KNMI has developed four climate scenarios for the Netherlands; indicated by G, G+, W and W+. They replace the scenarios that were drawn up in 2000 for the National Commission on Water management in the 21st century (WB21; see Previous generation scenarios).
A schematic overview of these KNMI'06 climate scenarios is shown in Figure 1. In Table 1 the climate change in the year 2050 is expressed in numbers for each scenario. Scientific background information on how these scenarios have been constructed can be found in the Methodology section, in the KNMI'06 scenario report and in several scientific papers published in the international literature (see Further reading). The contents of these webpages is taken from the KNMI'06 scenario brochure.
Figure 1 Schematic overview of the four KNMI'06 climate scenarios. 'G' is derived from 'Gematigd' = Dutch for 'Moderate'.
Table 1 Climate change in the Netherlands around 2050 (top) and 2100 (bottom) compared to the baseline year 1990, according to the four KNMI'06 climate scenarios. The climate in the baseline year 1990 is described with data from the period 1976 to 2005. The seasons are defined as follows: 'winter' stands for December, January and February, and 'summer' stands for June, July and August.
2050
G
G+
W
W+
Global temperature rise
+1°C
+1°C
+2°C
+2°C
Change in air circulation patterns
no
yes
no
yes
Winter
average temperature
+0,9°C
+1,1°C
+1,8°C
+2,3°C
coldest winter day per year
+1,0°C
+1,5°C
+2,1°C
+2,9°C
average precipitation amount
+4%
+7%
+7%
+14%
number of wet days (≥0,1 mm)
0%
+1%
0%
+2%
10-day precipitation sum exceeded once in 10 years
+4%
+6%
+8%
+12%
maximum average daily wind speed per year
0%
+2%
-1%
+4%
Summer
average temperature
+0,9°C
+1,4°C
+1,7°C
+2,8°C
warmest summer day per year
+1,0°C
+1,9°C
+2,1°C
+3,8°C
average precipitation amount
+3%
-10%
+6%
-19%
number of wet days (≥0,1 mm)
-2%
-10%
-3%
-19%
daily precipitation sum exceeded once in 10 years
+13%
+5%
+27%
+10%
potential evaporation
+3%
+8%
+7%
+15%
Sea level
absolute increase
15-25 cm
15-25 cm
20-35 cm
20-35 cm
2100
G
G+
W
W+
Global temperature rise
+2°C
+2°C
+4°C
+4°C
Change in air circulation patterns
no
yes
no
yes
Winter
average temperature
+1,8°C
+2,3°C
+3,6°C
+4,6°C
coldest winter day per year
+2,1°C
+2,9°C
+4,2°C
+5,8°C
average precipitation amount
+7%
+14%
+14%
+28%
number of wet days (≥0,1 mm)
0%
+2%
0%
+4%
10-day precipitation sum exceeded once in 10 years
+8%
+12%
+16%
+24%
maximum average daily wind speed per year
-1%
+4%
-2%
+8%
Summer
average temperature
+1,7°C
+2,8°C
+3,4°C
+5,6°C
warmest summer day per year
+2,1°C
+3,8°C
+4,2°C
+7,6°C
average precipitation amount
+6%
-19%
+12%
-38%
number of wet days (≥0,1 mm)
-3%
-19%
-6%
-38%
daily precipitation sum exceeded once in 10 years
+27%
+10%
+54%
+20%
potential evaporation
+7%
+15%
+14%
+30%
Sea level
absolute increase
35-60 cm
35-60 cm
40-85 cm
40-85 cm
How does our climate change?
A number of key characteristics of climate change in the Netherlands and surrounding areas are common across all the scenarios:
temperature will continue to rise. Mild winters and hot summers will become more common;
on average, winters will become wetter and extreme precipitation amounts will increase;
the intensity of extreme rain showers in summer will increase, however the number of rainy days in summer will decrease;
the calculated change in wind is small compared to the natural fluctuations;
the sea level will continue to rise. Detailed descriptions are provided for Temperature, Precipitation, Windstorms and Sea level.
The KNMI'06 climate scenarios present pictures of the changes in temperature, precipitation, wind, and sea level for a climatological period of 30 years. The scenarios for 2050 are, therefore, representative for the climate around 2050 (between 2036 and 2065). Likewise, the climate in the baseline year 1990 is described with data from 1976 to 2005. The numbers per KNMI'06 climate scenario do not include information on year-to-year variability and longer-term natural fluctuations, which also occurred in the past. Especially for wind these natural fluctuations are relatively large compared with the changes in the scenarios.
