The Norwegian Meteorological institute has celebrated its 150th anniversary this year. It was founded to provide weather data and tentative warnings to farmers, sailors, and fishermen. The inception of Norwegian climatology in the mid-1800s started with studies of geographical climatic variations to adapt important infrastructure to the ambient climate. The purpose of the meteorology and climatology was to protect lives and properties.
The journey from the early history of meteorology and climatology to the present weather forecasts and climate research is one of mankind’s great success stories. In the early days, there was a belief that the weather was influenced by sunspots and northern lights, but this notion lost its traction as meteorology and became more and more successful in forecasting.
Modern meteorology started in 1904 with a landmark theory proposed by Vilhelm Bjerknes that made it possible to compute how the atmospheric state changes over time, based on a set of key variables and differential equations. The progress was build on science and painstaking efforts, as described by Paul Edwards in his book “A Vast Machine”.
Today, weather forecasts ensure safety over a wider range of dimensions depending on where you are. Some of the most important sectors for Met Norway include roads, rail, aviation, and maritime operations. However, the general public and businesses are also important recipients, and they benefit from an open data policy and the popular weather portal Yr.no.
In the USA, the National Oceanic and Atmospheric Administration (NOAA) and National Aeronautics and Space Administration (NASA) provide a wide range of services. One example is the early warning systems for phenomena such as hurricanes which in the past took a large number of lives.
Why do meteorological services include both weather and climate, and how are they connected? Climate can be defined as the statistical description of weather, or the “typical weather” if you like. Long records of weather data is an essential part of climatology and you need a sufficiently large sample in order to get an accurate statistical description.
The statistical character of weather includes both the means, the range of variations, and the extremes. It is determined by the presence of physical processes, such as solar inclination (latitude), air mass above (elevation), prevailing winds, and how these are modified by the proximity of oceans and mountains.
I use the term climatology for the science-based knowledge about our climate, and this is built on climate research over time.
Climatology puts us in a better position to be prepared for a range of natural hazards and is a key element in risk handling. Risk R is often defined as the product between the consequence C of an event and the probability P that it takes place: R = C P.
Area planning is a typical examples of risk management, where the purpose is to avoid building in floodplains where floods are likely and to make sure that excess water drains efficiently. We also want to live where we are not killed by rockslides.
In mountainous Norway, we are particularly exposed to avalanches and rockslide hazards that may affect roads, rail, and buildings. Other types of exposure include wind (bridges) and storm surges (build environment). Operational meteorological services collaborate closely with homeland security and water authorities.
Weather data typically involve daily observations, and long series are essential to map the risks and quantify the typical frequency of extreme events. They are also essential for the evaluation of weather/climate model skill and for keeping an eye on the state of our climate.
Climate change means a shift in the weather statistics: Weather that was typical in the past may no longer be so common, and we start to see new types of weather events. Trend analysis and record-breaking occurrences can tell us if the probability for a particular type of events is changing. The climate changes because the physical conditions change, either from one location to the next, or over time as the greenhouse effect is increased.
Meteorology and climatology have been like two twins that have followed each other for a long time through our history. They have grown into modern sciences and are now a foundation for our safety. Weather forecasts and early warning systems represent the last line of climate change adaptation.
Recently, there have been some loud voices from people who find facts to be inconvenient and then try to make scientists look like villains. It is therefore important to remind ourselves that meteorology and climatology are your friends. At the same time, I would like to take the opportunity share this video that combines this message with a Merry Christmas greetings.