Sunday Times 2
Dreaming of a White Christmas in the context of climate change
View(s):By Prof. Mayuri Napagoda, University of Ruhuna
Even though Christmas was celebrated just a few days ago, the celebratory spirit continues to be visible all around. While nations in the southern hemisphere, such as Australia, South Africa, and Brazil, enjoy long, warm days in December, and tropical locales like Sri Lanka, the Maldives, and Fiji never experience snowfall, the typical image of Christmas continues to evoke scenes of snow-covered rooftops, frosty pine trees, and Santa Claus in a reindeer-pulled sleigh dashing through the snowy landscape. Therefore, snow and Christmas have an iconic association.
A snowless Christmas Eve in Lund, Sweden
This relationship has influenced a wide range of cultural elements, from folklore to festive decorations, music, and family practices. The lasting connection between Christmas and snow is seen in many instances, for example, in Charles Dickens’s “A Christmas Carol,” which portrays the snow-laden streets of London, while renowned classics such as “White Christmas” by Bing Crosby and the film “It’s a Wonderful Life” feature snowy settings, underpinning the notion that Christmas is intrinsically linked to snow. Ultimately, snow has established itself as a hallmark of the Christmas season, bringing an enchanting beauty that transforms typical environments into extraordinary winter scenes.
However, the picturesque snowy backdrop that traditionally accompanied Christmas in many countries in the northern hemisphere has become increasingly rare in recent years. Global climate change has altered the traditional image of a typical “white Christmas”. The sight of green grass replacing fresh snow has become more and more common in many cities that used to expect regular snowfall in December.
The last notable “white Christmas” across Europe where snow covered the ground in many areas was in 2010. Many countries, particularly in northern and central Europe, experienced considerable snowfall that year. I too had the good fortune to witness the fairy-tale charm of the white Christmas in 2010, yet I have not had the chance to experience that same magic in the subsequent Christmas seasons I spent in Europe. More than a decade later, I confronted my greatest disappointment on Christmas Eve in Lund, Sweden, with the absence of snow and instead with stretches of green grass across the ground. Even more surprisingly, a magnolia tree had burst with buds, making me wonder if spring had arrived early!
While the chemical composition of snow is the same as water (H₂O), its structure and physical state are different. Snow formation occurs when atmospheric water vapour freezes into ice crystals at temperatures below 0°C. This phenomenon begins with nucleation, where water vapour condenses around minute particles like dust or pollen. As the crystals expand by collecting more water vapour, they develop into elaborate, hexagonal structures influenced by the prevailing temperature and humidity levels. These ice crystals aggregate to create snowflakes, which will fall to the ground if the temperatures remain low enough. Snowfall is commonly observed in regions where cold air and ample moisture converge, particularly during winter storms or in high-altitude areas.
Snowfall is one of the most sensitive indicators of climate change. This highlights shifts in global water cycles, freshwater ecosystems, and human activities. Reduced snowfall will have an impact on life on Earth, from increased potential for wildfires to rising water insecurity and profound effects on biodiversity, with many species struggling to adapt to the changing conditions.
In some regions, the rise in temperatures has resulted in more precipitation occurring as rain instead of snow, coupled with earlier melting of snow. The scientific investigations have revealed that snow cover in the northern hemisphere has undergone marked changes in the past four decades. In addition, as stated by the European Environment Agency (EEA), Europe has experienced an average temperature increase of 1.5°C since the pre-industrial era, particularly pronounced in the Arctic and Mediterranean regions. This trend is expected to persist, with forecasts indicating a temperature rise of 2 to 5°C in Europe by the end of this century.
Even though long-term trends indicate a decline in snowfall in the northern hemisphere, particularly in Europe, short-term atmospheric conditions and dynamics can still generate notable snowfall, as has been observed recently. While the trend of global warming often results in less severe winters and a decline in snow cover, it can also intensify specific weather phenomena. Increased temperatures can lead to higher levels of moisture in the atmosphere, which can intensify snowstorms when cold air masses are present. Additionally, alterations in the jet stream behaviour (i.e., relatively narrow bands of strong wind in the upper levels of the atmosphere) and polar vortex activity (i.e., the counter-clockwise flow of air that helps keep the colder air near the Poles) influenced by Arctic warming can cause prolonged cold spells and substantial snowfall in certain regions.
The heavy snowfall in Europe experienced during late November this year had sparked some hopes for a traditional white Christmas, yet many people in various European countries were disappointed to find no snow on Christmas day. The people in Oslo (Norway), Reykjavik (Iceland), Innsbruck (Austria) and Zurich (Switzerland) were fortunate to enjoy the charm of a white Christmas with snow-covered landscapes adding to the festive spirit as those cities had temperatures near or below freezing and conditions suitable for snow cover/snowfall. On the other hand, the temperatures in Paris (France), Berlin (Germany), Prague (Czech Republic), Stockholm (Sweden), Helsinki (Finland), Vienna (Austria) and London (United Kingdom) on Christmas Eve were above freezing, which diminished the likelihood of snow. Therefore, the residents of these cities encountered a “green Christmas.” So the snow-covered streets of London depicted in “A Christmas Carol” have become a mere illusion 181 years after the publication of the novel in 1843.
Currently, certain regions around the world still have the potential for a white Christmas, though its future is ambiguous. This has led us to question if the iconic snow-blanketed holiday will one day become a relic of the past for a larger portion of the globe. So we have a responsibility to preserve the captivating image of a white Christmas that features snow-draped rooftops, glistening ice-covered trees, snow sculptures like adorable snowmen, etc. for future generations to cherish.
The researchers who have been examining the implications of climate change suggest strategies like decreasing greenhouse gas emissions through a shift to renewable energy sources and the implementation of energy efficiency initiatives could help to alleviate this problem. People can play a vital role in mitigating climate change and help sustain the tradition of a white Christmas. Simple actions like reducing energy consumption, using sustainable transportation modes, and adopting renewable energy sources can significantly lower greenhouse gas emissions.
Supporting sustainable practices such as recycling, minimising waste, and opting for eco-conscious products further contributes to environmental protection. Planting trees and conserving green spaces help absorb carbon dioxide and maintain local ecosystems. Advocating for policies that address climate change and raising awareness can motivate collective efforts, ensuring that future generations can also enjoy the magic of snow-filled Christmases.