Finland - Climate

Although seasons occur everywhere, in Finland they mark the progress of the year with striking conspicuousness. Extending far beyond the Arctic Circle, Finland enjoys such extremes of temperature and daylight that it would not be too far-fetched to say that there are two cultures in Finland: one dominated by the almost perpetual daylight of the summer sun and surprisingly high temperatures, and the other characterized by mercilessly cold winters and Arctic gloom that only briefly gives way to twilight during the day. The existence of a winter season that lasts for half of the year is reflected in the fact that the Finnish language has innumerable words and expressions for describing different kinds and conditions of snow and types of snowdrift and snowstorm. The natural environment of the north has provided the Finns with a living over the centuries, but the cold climate has also forced them to spend a good deal of time indoors and at school.

The miracle of spring, the awakening of the flora and fauna, is something that has to be seen and experienced with all the senses and all the emotions. Even though summer comes every year, it is considered so important that virtually the entire country ‘shuts down’ for the five or six weeks that follow Midsummer, which falls in late June. After Midsummer, Finns move en masse to their vacation homes in the countryside and those who do not spend their time out of doors, in street cafés and bars, in parks and on beaches, being social and feeling positive. Business and personal correspondence may be temporarily shelved, e-mails cheerfully return ‘out of the office’ notifications for a month or more, and conversations between acquaintances revolve more around how the fish are biting or how the garden is doing than around important issues of international politics or the economy.

The Finnish climate is milder than that of most continental regions in the same latitude range (60–70N). The basic features of the Finnish climate also include variations between days, years and decades. Finnish nature has adapted itself to this variation in weather and climate. Modern society aims to control the risks caused by weather and climate variation through anticipation and planning. Indeed, adaptation to the variations of the present climate and preparation to climate change are in certain respects similar problems.

The annual mean temperature of Finland has increased by approximately one degree since the middle of the 19th century. Warming has been most intense in the spring months. The mean temperature in March, April and May is currently approximately two degrees higher than in the middle of the 19th century. Temperatures have rapidly increased since the 1970s, particularly in winter. The daily range of temperature variation has also become narrower, which is probably attributable to increased cloudiness. Trends have been observed in many other variables describing the climate (such as precipitation and wind), but these cannot be statistically distinguished from natural climatic variation.

The Finnish Government submitted a Government Report on the National Climate Strategy to the Parliament in March 2001. The Parliament stated in its response in June 2001 that the implementation of the National Climate Program could be started but, in addition, there was a need to formulate a program for adapting to climate change. Thus the Parliament’s response required that the drafting of a program for adaptation to climate change be started.

The climate change predicted for this century may gain in intensity later on and have significant impacts. Most of the Greenland continental ice sheet could melt within the next one thousand years, causing the sea level to rise by seven metres. The thermohaline circulation in the oceans, including the Gulf Stream, will probably weaken during this century, which will curb the climate warming in the North Atlantic region. In Finland, however, intense warming is expected. It is unlikely that the Gulf Stream will stop flowing during this century.

The average sea level in the oceans is expected to rise by 0.09–0.88 metres between 1990 and 2100. The water cycle will intensify, and mean precipitation will increase. However, regional variations in the changes will be considerable. The rainfall will probably increase the most in high latitudes (to the north of 60N), particularly in the winter.

The FINSKEN project prepared a climate scenario for Finland using results from global climate models. Towards the end of the century, the average changes caused by different emission scenarios differ from each other. The greatest emissions cause the greatest changes in temperature and precipitation both in Finland and globally. Scenarios for the changes in Finland’s temperature and precipitation in different seasons suggest that temperatures will increase in all seasons, particularly in winter. Precipitation will also increase especially in winter. The total precipitation in summer will probably only change slightly and, according to some modelling results, may even decrease.

The trends of some climate variables observed in recent decades may even be opposite to the estimated changes caused by increases in greenhouse gases during the latter half of the current century. Differences between the observed changes and the climate scenarios may be due to the fact that trends caused by the intensified greenhouse effect remain fairly weak in comparison to natural climatic variation.

At present all Finnish harbors are frozen at least part of the time during normal winters. In front of Kemi the sea is frozen for the average of 183 days and in Kotka for 120 days (“ice-winter”). The entire Baltic Sea may be covered with ice during very severe winters. The time series describing the greatest annual extent of Baltic ice cover starts in 1720. According to observations, the maximum extent of the ice cover has a strong correlation with atmospheric temperature and atmospheric flow conditions.

According to studies, the severity of winter periods with frozen sea will signifi cantly decrease towards the end of the century. It has been estimated, on the basis of changes in the extent of ice, that the operating season of icebreakers will be shortened. The maximum ice cover in winter will decrease to 54–80% of the present, depending on the model and scenario. Towards the end of the century, the duration of the ice-winter will have shortened to one-half of the present on the southwestern and southern coasts of Finland, and to 70–80% of the present in the Gulf of Bothnia.