The phenomenon of global climate change, which is often referred to as global warming, pertains to the gradual and long-term alterations in the Earth's climate system, primarily influenced by human activities such as deforestation and the combustion of fossil fuels [1]. Although there are naturally occurring factors that impact the planet's climate such as volcanic gas emissions and variations in its orbit, the emission of greenhouse gases, particularly carbon dioxide, methane, nitrous oxide, and fluorinated gases, has risen significantly. This results in an increase in the Earth's temperature, leading to consequential impacts such as rising sea levels, melting glaciers, and changes in flowering and plant blooming periods [3]. Climate change is undeniably one of the most pressing challenges that we face today, due to its environmental, economic, and human health implications. Here are three factors that are considered harbingers of global climate change:

1. Increasing Temperatures

The planet's average surface temperature has risen by approximately 2 degrees Fahrenheit (1 degree Celsius) since the late 19th century [5]. Over the last four decades, this increase in temperature has been most intense, with the last seven years observed to be the warmest [5]. This rise in temperature is primarily due to the elevated concentrations of greenhouse gases that are released in the atmosphere. Human activities such as burning coal, oil, and gas produce carbon dioxide, which is the largest contributor to global warming. By 2020, the concentration of carbon dioxide in the atmosphere had surpassed levels recorded before the industrial era by 48% [2]. These greenhouse gases trap heat from the sun, which subsequently leads to rising temperatures. Furthermore, deforestation and other human land-use changes cause a decrease in the amount of carbon dioxide absorbed by plants, which contributes to global warming.

The consequences of rising temperatures contribute significantly to climate change; the increased temperatures can lead to melting polar ice caps resulting in rising sea levels and abnormal weather conditions. The warming of oceans also results in more frequent and extreme weather incidences such as hurricanes and cyclones [6]. Additionally, the increased temperatures can lead to altered precipitation patterns, including frequent and severe droughts and flooding in various regions.

2. Ocean Acidification

Apart from rising temperatures, increased carbon dioxide concentrations in the atmosphere due to human activities have led to ocean acidification. About one-third of the carbon dioxide released into the atmosphere by human activities is absorbed by the oceans [7]. When carbon dioxide dissolves in seawater, it creates carbonic acid, lowering the ocean's pH levels and increasing its acidity level by approximately 30% [7]. This phenomenon of ocean acidification has significant impacts on marine ecosystems; it affects the ability of some organisms to develop and maintain their shells and skeleton structures. This is because these shells and skeletons are made from calcium carbonate minerals, which are sensitive to the acidification effect [8]. Ocean acidification can lead to a decline in populations of these organisms, which could potentially impact the entire ecosystem. Moreover, ocean acidification can have repercussions on the food web and ecosystem services that humans rely on, such as fisheries and tourism. Addressing this issue requires sustained efforts to reduce greenhouse gas emissions and protecting vulnerable marine ecosystems.

3. Melting Ice

Another significant effect of global climate change is the melting of ice, which is evident in the retreating of glaciers and ice sheets. This phenomenon primarily occurs in polar regions, such as the Arctic and Antarctic, and leads to rising sea levels [3]. The melting of ice in these regions is caused by a combination of increasing temperatures, melting areas covered in snow, and a reduction in the amount of sea ice [3]. This melting trend has significant implications and could potentially lead to flooding and displacement of people living in coastal areas. It could also severely impact ecosystems in the polar regions, including the loss of habitats for indigenous species. To mitigate these effects, efforts to reduce greenhouse gas emissions must be upheld, and immediate measures taken to regulate human activities leading to the melting of ice in polar regions.

In conclusion, the impact of global climate change is a pressing issue that affects several aspects of our lives, including our environment, economy, and health. The factors mentioned above are only a few of the harbingers of global climate change, yet they signify the importance of grappling with this problem. Immediate action must be taken to address this issue to avoid potential future catastrophes.

In brief, climate change is evidenced by the connected phenomena of rising temperatures, ocean acidification, and melting ice. An upsurge in temperature occurs due to elevated greenhouse gas emissions, primarily carbon dioxide, which ensnare heat from the sun in the atmosphere, resulting in global warming. The warming engenders melting of glaciers and ice caps worldwide, creating a rise in sea levels and changes in ocean currents that adversely impact both ecosystems and humans. Additionally, the increased presence of carbon dioxide in the atmosphere has triggered ocean acidification, which impairs marine ecosystems. These three issues are interrelated and exacerbate each other, forming a complex and intricate web. A solution to these entwined problems necessitates a joint effort to decrease greenhouse gas emissions and mitigate the effects of climate change on fragile ecosystems and communities utilizing policy reforms, technological advancements, and individual actions.

References:

[1] United Nations. “What Is Climate Change?” Climate Action. https://www.un.org/en/climatechange/what-is-climate-change (accessed April 11, 2023).

[2] European Commission. “Causes of climate change.” Climate Action. https://climate.ec.europa.eu/climate-change/causes-climate-change_en (accessed April 11, 2023).

[3] NASA Climate Kids. “What Is Climate Change?” March 2023. https://climatekids.nasa.gov/climate-change-meaning/ (accessed April 11, 2023).

[4] British Geological Survey. “What causes the Earth's climate to change?” 2023. https://www.bgs.ac.uk/discovering-geology/climate-change/what-causes-the-earths-climate-to-change/ (accessed April 11, 2023).

[5] Callery, Shannon. “Climate Change Evidence: How Do We Know?” Climate Change: Vital Signs of the Planet, April 5, 2023. https://climate.nasa.gov/evidence (accessed April 11, 2023).

[6] The Editors of Encyclopaedia Britannica. “Global warming - Ice melt and sea level rise.” https://www.britannica.com/science/global-warming/Ice-melt-and-sea-level-rise (accessed April 11, 2023).

[7] National Oceanic and Atmospheric Administration. “Ocean acidification.” April 1, 2020. https://www.noaa.gov/education/resource-collections/ocean-coasts/ocean-acidification (accessed April 11, 2023).

[8] Doney, Scott C., et al. “The Impacts of Ocean Acidification on Marine Ecosystems and Reliant Human Communities.” Annual Review of Environment and Resources, vol. 45, no. 1, October 2020, pp. 83–112, doi: 10.1146/annurev-environ-012320-083019.

[9] Hancock, Laura. “Why are glaciers and sea ice melting?” World Wildlife Fund, 2023. https://www.worldwildlife.org/pages/why-are-glaciers-and-sea-ice-melting (accessed April 11, 2023).

[10] University Corporation for Atmospheric Research. “Climate and Ice | Center for Science Education.” 2019. https://scied.ucar.edu/learning-zone/climate-change-impacts/climate-and-ice#:~:text=Melting%20ice%20causes%20more%20warming.&text=Because%20they%20are%20darker%20in,is%20known%20as%20a%20feedback. (accessed April 11, 2023).