Natural causes of global warming

Many people have the perception that global warming is mainly the result of pollution and the increase in green house gasses produced by the human beings. They might not be aware that there are other natural global warming causes. These natural factors can indeed have large impact on the Earth’s overall temperature, as seen in pre-historic times.

Solar activities are observed to vary in cycles, like the 11-yr sunspot cycle. Changes in the sun’s activity is in turn observed to change the magnetic activity in and around the sun. This magnetic field plays a significant role in deflecting cosmic rays (charged particles originating from exploding stars in the galaxy) from the Earth. At times when the sun dims and its magnetic field drops, the cosmic rays penetrate deeper into our solar system.

Larger numbers of the charged particles then enter our lower atmosphere, where they ionize small particles of moisture, causing them to aggregate into water droplets and then clouds. Low clouds that are optimally thick are efficient in reflecting sun energy back to space. Sufficiently large increase in Earth’s cloud cover could lead to drop in global temperature.

Other solar variations, like changes in solar irradiance in wavelengths (e.g. Ultra-violet or visible wavelengths), might also be linked to changes in atmospheric temperatures. The exact relation between solar radiation and global warming, and the relative importance of solar radiation versus green house gasses in causing global warming, is still being studied and deliberated.

Natural forest fires, especially large scale ones over long periods, can have an impact on the global temperature. When the vegetation burns, there is release of stored carbon and an increase in green house gasses like carbon dioxide into the atmosphere. These greenhouse gasses then traps solar energy, inevitably leading to the warming of the atmosphere. The soot and harmful gases produced also cause air pollution.

Disturbances, such as changes in solar activity, natural forest fires and volcanic eruptions etc, to these natural carbon storage areas may result in the large scale melting of permafrost, in turn leading to the large scale release of the green house gas into the atmosphere. As the carbon in permafrost have been out of the atmosphere for thousands of years, the sudden release of these sequestered carbon into the atmosphere will definitely result in imbalances in the carbon cycle and other natural processes.

However, even though our irresponsible way of life is not the only cause of global warming on Earth, our responsibility for causing the Earth’s warming today is not negligible. In fact, we are rapidly hastening the global warming process with our large scale emission of carbon dioxide gas into the atmosphere. Read related articles on the human causes of global warming.

We need to do something to reduce our carbon footprint today, before global warming becomes self-sustaining and we are faced with the eventually destruction of the entire planet (imagine planet Earth becoming like its sister planet, Venus, which has a temperature of 250 centigrade and rains sulfuric acid). Read about the consequences of global warming.