The sun’s role in our recent climatic changes remains quite controversial. The argument actually may seem logical considering the fact that sun is a huge mass of fire that has been constantly burning for millions and millions of years. This solar activity provides energy that fuels life on earth and the sunlight that falls on earth changes climatic conditions on earth dramatically.
The rate of solar energy falling on the earth keeps decreasing every day. This change in solar output affects the earth’s climate directly and indirectly. However, is the sun’s activity actually responsible for the global warming?
Studies have confirmed rise in average temperature of up to 1 degree Celsius globally since half a century now. This rise in temperature experienced is at troposphere levels, while the upper atmosphere is getting cooler because lesser energy from the sun is falling on earth. This phenomenon explains that the rise in temperature is due to greenhouse emissions.
Cosmic rays and its effects
A prominent argument is that the changes in solar activity influence the cosmic rays that fall on the earth. Cosmic rays are small, charged, highly energetic particles present in the atmosphere. These rays would combine with solar particles to reduce the ozone in stratosphere, which in-turn would affect the climatic conditions of the troposphere causing cloud formation and pushing of storms. However, in the lower stratosphere area the cosmic rays would combine with the UV rays from the sun and break down ozone molecules making it warmer there. As confusing as it may sound, these phenomenons are also considered game changer concerning the recent climatic conditions. Scientists have explained that when the ozone is removed, the stratosphere becomes cooler and this in-turn causes instability in temperatures at polar and tropical regions. Because of this instability, there is an irregular flow of currents. But it is hard to explain their direct link to climatic changes we see today.
The sun’s source of energy has played very little role in the climatic changes we see today. Satellite measurements from the past 50 years show that there has been no drastic increase in solar output while there has been considerable change in earth’s surface temperatures.
Effects of solar cycle
The sun’s temperament varies on an 11-year solar cycle. Physicists study the solar cycle by observing the sunspots present on the surface of the sun. Sunspots are dark blotches on the surface of the sun caused by intense magnetic activity. The frequency and their number indicate the solar maximum and solar minimum periods during the solar cycle. These sunspots are generally seen along the middle region of the sun. Occasionally the sunspot erupts and throws out charged particles into the space, which is capable of knocking down the power grids and satellites of the earth. However, this variation in the intensity of sunlight that falls on the earth is only 0.1 percentages and cannot contribute to major climatic changes.
The research needed to support the subject is still ongoing and will take considerable amount of time before we can actually conclude to something solid. However, for now we just know that the smallest change in solar activity can bring about changes in Earth’s climatic conditions.
The NRC – National Research Council has appointed experts in plasma physics, atmospheric chemistry, energy particle physics, fluid dynamics and many other domains to learn how these tiny variations in solar activity can bring about changes in the climatic conditions on earth.
For now, it is quite evident that the recent climatic changes of the earth are due greenhouse emissions brought about by man and his needs to make life “better”.