A recent study revealed that the diminishing ice and snow cover in the Northern Hemisphere is reflecting less sunlight back into space than previously thought, potentially contributing to global warming. Satellite data from 1979 to 2008 showed that Arctic sea ice, glaciers, winter snow, and Greenland's ice were reflecting less energy back to space. This decrease in reflection exposes darker ground or water, which absorb more heat, leading to a reduction in the cooling effect. The study estimated that ice and snow in the Northern Hemisphere now reflect an average of 3.3 watts per square meter of solar energy back to the upper atmosphere, a decrease of 0.45 watt per square meter since the late 1970s. Mark Flanner, an assistant professor at the University of Michigan and lead author of the study, explained that this reduction in the cooling effect is causing the planet to absorb more solar energy. He stated that the decrease in reflected solar energy due to warming is more significant than what is predicted by current climate models. The research, conducted by a US-based team and published in Nature Geoscience, suggests that the cryosphere, which includes ice and snow-covered areas, is more sensitive to and influential in driving climate change than previously thought. The exposure of more ground and water to sunlight leads to increased heat absorption, accelerating the melting of nearby snow and ice. The shrinking of Arctic sea ice over the past few decades is primarily attributed to greenhouse gas emissions from human activities such as burning fossil fuels. It is projected that Arctic sea ice could completely disappear during summers later in this century, which would have negative impacts on indigenous hunting cultures, polar bears, other wildlife, and contribute to global climate change. Flanner emphasized that drawing conclusions about the future rate of melting, such as Arctic sea ice, from the study's findings is impossible due to the limited 30 years of data. He stated that climate is influenced by various factors, with the study only focusing on one aspect. Other factors to consider include the presence of more clouds in a warmer world, which reflect sunlight, and increased water vapor that traps heat in the atmosphere. The study projected that for every one degree Celsius rise in temperature, there would be a decrease in solar energy reflected out to space from the Northern Hemisphere's snow and ice ranging from 0.3 to 1.1 watts per square meter. Temperatures in the Northern Hemisphere have increased by approximately 0.75 degrees Celsius over the last 30 years. The study did not examine the Southern Hemisphere, where Antarctica has more ice but is colder and shows less evidence of warming. "On a worldwide level, the Earth absorbs solar energy at a rate of roughly 240 watts per square meter annually. The Earth would be darker and absorb an extra 3.3 watts if it weren't for the cryosphere in the Northern Hemisphere," according to Flanner.