Climate change has far reaching impacts, including surges in extreme weather events, rising sea levels, and increases in the frequency of droughts. Global warming drives this change. In this list, we share the top causes of shifting temperatures and global warming to understand ways it can be mitigated.
Recent events have demonstrated that the climate is changing at an unprecedented rate. The severity of this situation was underscored by relentless heatwaves that gripped Europe in 2022, resulting in the evacuation of many and the tragic loss of more than 20,000 lives due to heat-related illnesses. Also in 2022, Pakistan experienced a series of devastating floods, killing over 1,700 people.
The cause of climate change comes from the ‘greenhouse effect,’ where potent gases trapped in the atmosphere prevent heat from being radiated back into space. Instead, they retain heat and have a general warming effect.
But, what are the human causes of global warming?
#6 Refrigerants and other chemicals
No matter where you are in the world, we all depend on cooling devices. Without refrigeration, our food would spoil quickly, milk would curdle rapidly, and the risk of food poisoning would increase significantly.
However, certain chemicals used in refrigeration and other industrial processes can also be potent and damaging greenhouse gases.
The most common refrigerants found in domestic fridges is HFC-134a, which has a global warming potential 3,400 times that of carbon dioxide. A standard fridge can hold anywhere between 0.05 kg and 0.25 kg of refrigerant, and if it were to escape into the environment, the resulting emissions would be equivalent to driving an average family-sized car for between 420-2,130 miles.
The cooling industry is important, but it is also incredibly polluting – accounting for around 10% of global CO2 emissions, heavily driving climate change.
#5 Landfills
Landfills represent a significant source of methane emissions, with decomposing organic waste being a major contributor of the potent greenhouse gas. Methane is around 25 times more potent at warming than carbon dioxide, and while waste occurs at every stage of the process (from production to consumption), wastage from consumers generates the most by far.
According to the US Environmental Protection Agency (EPA), 94% of discarded food ends up in landfills, where it decomposes and releases methane and carbon dioxide into the atmosphere. The impact of food waste on the environment is considerable, accounting for approximately 8% of global greenhouse gas emissions.
#4 Agricultural practices
Agricultural land covers roughly 5 billion hectares, representing about 38% of the earth’s surface area. Of this, approximately one-third is allocated for crop production, which typically relies on agricultural techniques like the application of fertiliser to boost yields. Unfortunately, these practices can also produce potent greenhouse gases, such as nitrous oxide, which is roughly 300 times more effective at warming the atmosphere than carbon dioxide – one of the potent causes of climate change.
Estimating the proportion of global emissions that result from agricultural activities depends on several variables, but it’s estimated that our food systems account for approximately 21–37% of total global emissions.
#3 Livestock
Continuing on the agricultural theme as a cause of global warming, if crop production is responsible for around one-third of all agricultural land area, the remaining two-thirds consists of meadows and pastures for grazing livestock.
Cows, and other livestock produce and expel significant amounts of methane as part of their digestive processes. In the future, scientists are hoping that small tweaks in what cows eat can dramatically reduce a big source of climate emissions.
Overall, livestock is estimated to be responsible for around 14.5% of global greenhouse gas emissions.
#2 Deforestation
While not a producer of atmosphere warming greenhouse gasses, trees are capable of storing significant amounts of emissions from elsewhere, this has seen them often referred to as the ‘lungs’ of the Earth.
However, the data is alarming: every year, approximately 15 billion trees are cut down worldwide, with a staggering 24 million hectares of global tree loss in 2019 alone, equivalent to the land area of the United Kingdom. As a result, deforestation is heavily responsible for climate change by accounting for between 12% – 20% of total global greenhouse gas emissions, according to the scientific publication Our World in Data.
Beyond their remarkable ability to capture and store carbon from the atmosphere, forests also serve as vital ecosystems for a diverse range of wildlife. Moreover, they play an essential role in preventing floods by substantially reducing the volume of rainwater that enters waterways.
#1 Burning fossil fuels
Out of all the causes of global warming, burning fossil fuels is undoubtedly the most significant. We humans burn fossil fuels, such as oil & gas, for a wide range of activities that require energy in different forms.
Whether it’s producing electricity and heat for residential and commercial buildings, transportation in the form of automobiles, shipping, or aviation, or supporting industrial processes like mining and manufacturing, fossil fuels remain the dominant source of energy despite their damaging impact on the environment.
The most significant human activity contributing to greenhouse gas emissions is energy production, responsible for approximately 80% of all man-made emissions in the USA and the European Union. Although electricity only accounts for 20% of final energy consumption, the generation of electricity produces more than 40% of all energy-related emissions.
It is important to note that emissions are not only produced from the combustion of fossil fuels, but also during the extraction process.
