Climate change is taking away our winter

Snowy landscapes, like the one in the photo, are becoming an increasingly rare sight in Poland and around the world. Climate change, driven by greenhouse gas emissions, is gradually depriving us of winter by shortening the number of days with temperatures below 0°C. Data from the Climate Central report published in December 2024 shows that Poland, losing an average of nearly three weeks of cold days annually over the past decade, is among the countries most affected by this phenomenon. Global warming not only changes the face of winter but also disrupts the natural cycles of nature and the economy.

The Lost Winter report

The Lost Winter report, prepared by Climate Central, provides a detailed analysis of the impact of climate change on winter temperatures between 2014 and 2023. The study covered 123 countries in the Northern Hemisphere and 901 cities, including 13 in Poland. Its aim was to determine how global warming has affected the number of winter days with minimum temperatures above 0°C — so-called “lost winter days.”

The study utilized meteorological data from the ERA5 system and the Climate Shift Index (CSI) methodology, which estimates what the climate would look like without human influence. The analysis compared actual temperatures with those that would have occurred in a hypothetical world without greenhouse gas emissions. Results were presented at national, regional, and city levels, highlighting specific trends.

The global impact of disappearing winter frost

Globally, climate change has led to a noticeable increase in the number of winter days with temperatures above 0°C. In the past decade, 44 of the 123 countries analyzed experienced at least one additional week of such days per year on average. This phenomenon particularly affects cities in Asia and Europe, such as Riga in Latvia and Fuji in Japan, which have lost over three weeks of winter days annually. In the United States, 28 states have been significantly affected, including Arizona and Washington, where the number of days with temperatures above 0°C increased by over a week per year. This phenomenon impacts local ecosystems by reducing snow levels that would otherwise replenish rivers and reservoirs in spring.

Europe leads the way

Europe, as the fastest-warming continent, is experiencing particularly dramatic changes. Over the past decade, many European countries have seen a significant increase in the number of lost winter days. The Baltic States, including Lithuania, Latvia, and Estonia, have been the hardest hit, with an average of more than three additional weeks of days above 0°C each winter. Similar trends are observed in Denmark. These findings are especially alarming given that winter in Northern Europe plays a crucial role in sustaining local ecosystems and the economy, particularly the winter tourism sector. Countries like Germany, the Czech Republic, Belgium, and Norway have also reported an average increase of two to three weeks of additional days with temperatures above freezing.

Poland among the leaders in lost winters

Poland, due to its geographical location, is particularly vulnerable to the effects of climate change in the context of winter. The study included 13 Polish cities, each of which experienced at least two additional weeks of winter days with temperatures above 0°C annually compared to a decade ago. Szczecin, the city most affected by warming in Poland, reported as many as 23 additional days above freezing per year, significantly impacting the local ecosystem, economy, and winter tourism. Gdańsk, Lublin, Poznań, and Warsaw have also experienced significant changes, with an average increase of 20–21 days annually. Even mountainous regions like Wałbrzych reported an increase of 16 days, a notable change for skiing tourism and water resources, which rely heavily on snowfall.

What do the results mean?

Climate change, which reduces the number of cold winter days, has serious consequences for nature, the economy, and public health. Limited snow cover affects groundwater and river resources, leading to water shortages in spring and summer that are crucial for agriculture and industry. Disrupted plant growth cycles, especially for fruit trees and grains, increase the risk of crop losses, while earlier springs expose crops to frost. Meanwhile, warmer winters promote the proliferation of pests such as ticks and mosquitoes.

For mountain regions, shorter winter seasons mean losses in tourism, particularly in winter sports, which increasingly require artificial snow. The changes also impact public health — mild winters allow viruses and bacteria to survive longer and worsen air pollution. Reduced snowfall limits water supplies from meltwater, critical for _{hydroelectric systems}, increasing the risk of droughts and energy shortages. The scale of these challenges demands urgent adaptation measures, investments in water management, and reductions in greenhouse gas emissions to counteract the ongoing effects of global warming.