The debate of whether the sun is responsible for global warming is one that has long divided experts. For many years, many have attributed the rise in global temperatures to changes in the sun’s energy output. However, recent studies have thrown doubt on this idea, expressing doubts about its validity and suggesting some alternative causes for the increase in the average temperature. In this article we shall investigate these ideas, presenting evidence and exploring the debate from both sides.
At the core of the argument is the fact that a large amount of energy is emitted by the sun each day – around 1366 watts per square meter – and this energy is absorbed by the Earth. A decrease in the sun’s energy output would lead to a lowering of temperatures here on Earth. The solar output is known to vary slightly over time and many scientists have claimed to have observed a decrease in solar radiation in recent decades. This is sometimes referred to as ‘global dimming’, a phenomenon which may help to explain recent temperature rises.
It has been suggested that this decrease in solar radiation is a result of an increase in the amount of aerosols in the atmosphere, caused by human activities, such as burning fossil fuels. These aerosols are thought to scatter and block some of the sun’s rays, preventing them from reaching the Earth’s surface. This leads to a decrease in temperatures and may account, in part, for the observed rise in global temperature levels.
However, there is still much disagreement among scientists as to how much of an impact the sun’s energy output has on global warming. Some believe that changes in solar energy are having a significant impact, while others reject the idea entirely, attributing the bulk of warming to man-made greenhouse gas emissions. One study by the International Panel on Climate Change suggested that the sun’s output had declined since the 1950s, but concluded that it was not the primary cause of observed temperatures rises, as it could only account for around 4-5% of the global warming observed since the 1970s.
The accepted scientific consensus is that the majority of global warming is due to an increase in greenhouse gases, emitted by human activities, such as burning fossil fuels, deforestation and agricultural practices. This is supported by studies which show that human activities have released over 13 million million tons of carbon dioxide into the atmosphere since 1750. This increase in carbon dioxide has lead to an increase in temperatures, as it traps and holds more heat than would otherwise be released back into space.
It seems clear then, that while changes in the sun’s energy output may have contributed to recent rises in global temperatures, the majority of the increase is a result of human activities, rather than natural changes in the Earth’s climate. To limit the effects of global warming, it is important to focus on reducing greenhouse gas emissions and increasing renewable sources of energy. Only through a concerted effort, both nationally and internationally, can we hope to mitigate the worst effects of climate change and protect our planet for future generations.
