Snow, ice and climate change
The surface of the Earth contains many forms of snow and ice, including sea, lake, and river ice; snow cover; glaciers, ice caps, and ice sheets; and frozen ground. Global warming can cause these forms to change from solid to liquid, drastically changing the appearance of the regions affected by this change.
Such changes can lead to serious adverse effects on humans and the environment:
- Reduced snow cover on the ground could diminish the beneficial insulating effects of snow for vegetation and wildlife, while also affecting water supplies, transportation, cultural practices, travel, and recreation for millions of people.
- For communities in Arctic regions, reduced sea ice could increase coastal erosion and exposure to storms, threatening homes and property of local people.
- The thawing ground could damage roads and buildings and accelerate erosion.
Changing climatic conditions can have consequences for the whole world, as snow and ice affect air temperature, sea level, ocean currents and storm patterns. For example:
- Increased melting of the ice sheets of Greenland and Antarctica adds fresh water to the ocean, raising sea levels and possibly changing the circulation of ocean currents, whose movement is due to differences in temperature and salinity.
- Due to their light color, snow and ice reflect more sunlight than open water or bare ground, so reducing snow and ice causes the earth's surface to absorb more energy from the sun and become warmer.
Reducing snow and ice cover could also have a positive effect on people's lives. For example:
- To revive the northern trade routes after the ice receded;
- To facilitate access to natural resources, which are currently under ice or snow cover, etc.
Long-term observations and research related to the impact of climate change on the snow and ice cover of the Earth show:
- Part of the Arctic Ocean is covered with ice all year round. This area is usually the smallest in September, after the summer melting season. The annual minimum amount of Arctic sea ice has decreased over time and in the last 2 years was the second smallest recorded ever. The length of the Arctic ice melting season has increased and the ice has become thinner, making it more vulnerable to further melting.
- Since 1992, the giant ice sheet in Greenland and Antarctica has shrunk. The melting ice is causing rise of the world oceans by about 18 mm. This represents about a quarter of the total sea level rise during this period.
