Written by Yifei He (G10)

The broader phenomenon of climate change, which refers to modifications to all aspects of Earth’s climate system, is closely linked to global warming. Changes in precipitation patterns, winds, ocean currents, and other indicators of Earth’s climate are all part of climate change, in addition to variations in air temperature (NASA, 2022). 

The fact that the Earth’s climate is constantly changing, both over human lifetimes and billions of years, makes a significant impact on global warming and climate change. Such changes are often subdivided into several “epochs.” For example, variations in glacier coverage were pronounced during the Pleistocene epoch, between approximately 2.6 million and 11,700 years ago. According to Nations (Nations, 2023), this was controlled by variations in the amount of sunlight resulting from the Earth’s tilt and orbit. When the last ice age reached its maximum extent twenty-one thousand years ago, global average temperatures were about 4-5 °C (7-9 °F) lower than the mid-twentieth century. Because the poles were cooler than the tropics, ice sheets extended as far as London and New York during this period. This ice age ended abruptly approximately 11,700 years ago, ushering in the Holocene epoch, the current era of geology. Some researchers suggest that the current geological epoch, in which human activity affects climate ecosystems even more strongly than natural factors, is the Anthropocene epoch (Nations, 2019). The climate evolved during the Holocene epoch, though not to the extent of the Pleistocene epoch. Around 9,000 years ago, the Sahara region experienced wetter conditions at the onset of the Holocene epoch. Some regions around the mid-Holocene epoch, about 5 to 7 thousand years ago, may have experienced warmer temperatures than the rest of the world, but that warming was not universal (Nations, 2019). The Northern Hemisphere experienced warmer summers but cooler winters due to variations in sunshine. During this period, overall average temperatures were probably slightly lower than the average temperatures of the late 20th century. Gradually, temperature changes improved, creating a phase that can be described as the ‘Neoglacial epoch’ when glaciers in the mountains advanced and began to retreat again (Nations, 2019).

Nowadays, the Earth’s energy budget is influenced by human-caused greenhouse gases, such as carbon dioxide, methane, and nitrous oxide. These gases absorb heat in the atmosphere, shifting climate and weather patterns both regionally and globally. Environmental pollution and greenhouse gases generated by humans have been the leading cause of global warming since the 20th century (Mann, 2024). Other studies highlight the sun and volcanic eruptions as contributing factors; however, since the late 1700s, the concentration of greenhouse gases has increased constantly worldwide (Mann, 2024). These gases influence the climate systems at different levels, such as air and ocean temperature, total precipitation, and sea level rise. These changes pose risks to human health, agriculture, water supply, forests, wildlife, and low coastal regions (Mann, 2024). Certain greenhouse gases have atmospheric lifetimes ranging from several decades to several centuries. As a result, they mix in the atmosphere globally, reflecting emissions from past and present activities. Tropospheric ozone, for instance, belongs to the latter category with a short lifetime (Mann, 2024). 

The dominant human-made greenhouse gas is carbon dioxide (CO₂), released into the atmosphere mainly from burning fossil fuels. The U.S. and China are among the countries primarily responsible for this increase, as natural processes such as oceans and plants work to regulate CO₂ levels. However, human activities can alter this balance; methane (CH2) comes from coal mining, natural gas extraction, landfills, and livestock. Industrial and household activities emit synthetic chemicals like hydrofluorocarbons and sulfur hexafluoride (US EPA, 2017). All greenhouse gases absorb heat, contributing to the greenhouse effect, but each one traps it with different strengths and for different amounts of time. For example, even a small amount of sulfur hexafluoride has a warming effect that is many thousand times stronger than carbon dioxide (US EPA, 2017). The IPCC evaluates these gases using a metric called “global warming potential,” which quantifies their contribution to the change in climate relative to CO₂ (US EPA, 2017).

Although issues such as climate change continue to burden our world, there are countless ways that we can modify and create changes in our lives to better assist in mitigating this issue for good. Examples include (United Nations, 2019): 

• Keeping up with your utility bill and saving on energy at home is essential. Your heating & cooling system, LED bulbs, and everything that helps. Opt for energy-efficient appliances. 
• Washing clothes in cold water and hanging them to dry. 
• Making your home more energy efficient (like insulating and changing from an oil or natural gas furnace to an electric heat pump) could save you up to 900 kg CO₂e/year. 
• In terms of energy, talk to your utility company about using renewable sources like wind or solar (it can save you up to $1 per month).
• When driving, you can lower your greenhouse gas emissions by avoiding it. For most of your transportation needs, walk, ride a bike, or take public transit. Living without a car saves up to 2 tons of CO₂e per year 
• If you’re in the market to buy an automobile, think about getting an electric one. Based on location, electric vehicles save an average of 1.5 to 2 tons of CO₂e emissions per year. However, be mindful of the source and other environmental costs associated with battery production (EV Lifecycle).
• Skipping air travel to decrease your footprint. It accounts for a large proportion of greenhouse gas emissions. Take fewer flights to decrease your impact when you travel. When possible, choose virtual meetings or even train travel. 
• Food waste is equally important to minimize. Buy what you will eat and compost the rest. Wasted food in landfills generates methane, which could also reduce your carbon footprint by 300 kg of CO₂ per year.
• To better improve and assist with helping the environment, you can start at home by growing and planting native crops in your yard, which will promote the growth of biodiversity and, therefore, act as a huge contribution to bettering the environment. 
• In addition to that, shopping locally or in shops that follow the same environmental values as you will benefit the environment, as the practices will be considered a lot more ethically better for the environment. 
• Furthermore, your contributions to clean-up events that promote eco-friendliness in the community can help combat environmental pollution by a huge margin (United Nations, 2019).

 Your help and assistance are needed for the world to become a better place!

Works Cited

“Greenhouse Gases | US EPA.” US EPA, 2 Nov. 2017, www.epa.gov/report-environment/greenhouse-gases#:~:text=This%20change%20in%20concentrations%20causes,all%20vulnerable%20to%20climate%20change. Accessed 25 Aug. 2024.

Mann, Micheal. “Global Warming – Climate Change, Glaciation, Effects | Britannica.” Encyclopædia Britannica, 2024, www.britannica.com/science/global-warming/Climatic-variation-since-the-last-glaciation. Accessed 25 Aug. 2024.

Nations, United. “Actions for a Healthy Planet | United Nations.” United Nations, United Nations, 2019, www.un.org/en/actnow/ten-actions#unplug. Accessed 25 Aug. 2024.

Nations, United. “Causes and Effects of Climate Change | United Nations.” United Nations, United Nations, 2023, www.un.org/en/climatechange/science/causes-effects-climate-change. Accessed 25 Aug. 2024.NASA. “Effects – NASA Science.” Nasa.gov, 15 June 2022, science.nasa.gov/climate-change/effects/. Accessed 18 Nov. 2024.