The Simple Truth of Climate Change [Part 2]

This article continues to uncover the fundamental causes of modern-day climate change. In Part 1, we unravelled the human-induced causes of global warming, while in this paper, we will present the natural causes of climate change.

This information is based on the review article "Causes of Climate Change: Review Article," [1] which assessed the causes of climate change through published and unpublished scientific papers, observations, and data analysis [1]. However, why are some of these scientific papers unpublished? A future article will discuss the various reasons for this.

Natural Causes 

• Sun Intensity [1]: Sun intensity is accountable for influencing the formation of clouds and the Earth’s temperature [1]. This is due to high amounts of solar radiation heating the planet [1] and increasing the formation of clouds [1], which can encourage certain weather events and reflect sunlight into space. 

• Earth’s Orbit [1]: It is natural for aspects of the Earth's orbit to change through 10,000 and 100,000-year cycles. These alterations include changes to the angle of the Earth's tilt [1], the distance between the sun and the Earth [1], and the eccentricity of the Earth's orbit [1] (how much of its orbit deviates from a circle [1]). All these factors impact the amount of solar radiation the planet receives, thus significantly affecting global temperatures.

• Ocean Current Circulation [1]: Ocean currents are directed by wind, temperature, and the rotation of the Earth [1]. They are responsible for transporting warm water from the equator to the poles and cool water from the poles to the equator, which is critical in distributing heat across the planet and a major influencer on climate globally [1].

Changes to these circulations due to alterations in greenhouse gas concentrations, sea level rises, tectonic plate movement, solar intensity, and climate fluctuations can greatly affect the frequency of weather events such as El Nino (warming, droughts, heatwaves) and La Nina (cool, floods, heavy rain).

• Volcanic Eruptions: When volcanic eruptions occur, they release particles and dust that block solar radiation from reaching the Earth’s surface [1], cooling the planet in the short term. An extreme example of this can be seen in 1816, ‘the year without summer, after the Mt. Tambora eruption.

In addition, eruptions spew large amounts of gases, such as carbon dioxide and water vapour [1], which trap heat. However, due to the small size of volcanoes, the gases released have minimal effect on the climate [1]. However, 4 billion years ago, when there were large amounts of tectonic plate movement [1], there were monstrous amounts of eruptions [1], which made Earth a representation of hell.

• Melting of Glaciers: The melting of glaciers has occurred since the 1960s, and the article credits this to human influences [1]. This includes the melting of Greenland ice sheets since 1993 and arctic sea ice loss since 1979 [1]. In addition, Antarctica and Greenland have lost 134 and 287 gigatons of ice per year since 2002 [1]. The rate of these melting events is expected to rise and occur globally [1].

The melting of these glaciers is said to have caused a rise in ocean temperature as well as the release of carbon dioxide and other pollutants stored in the ice [1]. Additional effects include sea level rises [1] and impacts on ocean circulations, leading to a lack of cool water circulating the Earth and thus warming the planet. Furthermore, ice and snow reflect sun radiation into space; however, the melting of glaciers is limiting this process, thus warming the surface and oceans further.

Interestingly, the review article only mentions humans for the melting of glaciers, even though glaciers have melted throughout Earth's history as recently as 5000 and 10,000 years ago. Reasons for the natural melting of glaciers are sun intensity (which could be due to changes in Earth's orbit), CO2 concentration, and ocean current circulations.

Even though the current melting of glaciers is occurring at an alarming rate and magnitude that has not been seen before, it is equally important to detail that the melting of glaciers has occurred naturally.

• Sea Level Rises: Sea levels rise due to thermal expansion (warming of the oceans causing the water to expand) [1] and melting of glaciers [1], adding fresh water to the surface. Correlations show that human interference may be causing current sea levels to rise [1]; however, sea levels have changed naturally previously.

As difficult as it can be to determine and project the causes of climate change [1], the simple truth is that humans play a significant role; however, nature has also always been a crucial factor in these changes.

 References

Reference paper “Causes of Climate Change: Review Article”.

1.       Fakana, S.T., 2020. Causes of climate change. Global Journal of Science Frontier Research, 20, pp.7-12.