Climate change impacts all aspects of human life, from water scarcity and drought to floods and heat-related illnesses. While the Earth has seen periods of warming and cooling before, records demonstrate that current climate change is happening faster than ever and is mostly human-caused.
Natural forces that influence climate change include volcanic eruptions that send airborne particles high into the stratosphere to reflect sunlight back down onto Earth, producing short-term cooling effects. Milankovitch cycles also play a part in altering Earth’s tilt and orbit around its Sun.
1. Fossil Fuels
Geological records reveal that climate change takes place over millions or even millennia; however, since the Industrial Revolution human activity has drastically accelerated this process. Coal and oil combustion is responsible for an acceleration in climate change due to carbon combined with oxygen in the air to form carbon dioxide; this increases greenhouse gases which heat the Earth further; it also creates environmental problems like acid rain combining water vapor, oxygen and other chemicals with sulfur dioxide and nitrogen oxides to form sulfur dioxide and nitrogen oxide pollutants which pollute freshwater sources, decreasing oxygen levels while killing fish species among other problems caused by industrial emissions.
Fossil fuels like coal, oil and natural gas are composed of the remains of photosynthetic plants and animals that died millions of years ago, providing us with energy essential for economic activity. They represent an invaluable source of power. Digging for and transporting these resources has serious environmental ramifications. Mining, drilling and transporting fossil fuels to power stations emit emissions such as mercury, SO2, NOx and particulates into the air. All forms of transportation emit carbon dioxide, an effective greenhouse gas. Agriculture and livestock production produces methane which is 30 times more potent than carbon dioxide; production of fertilisers and cement creates nitrous oxide – another potency greenhouse gas.
2. Deforestation
Deforestation refers to the deliberate clearing of trees and forests for any reason, with devastating results for the environment – including climate change. Trees play an essential role in sequestering carbon dioxide; when they’re removed from Earth they release it back into the atmosphere, contributing further to climate change by amplifying its effects.
Forests serve an integral role in stabilizing the water cycle by holding soil moisture and preventing erosion. When forests are removed, changes occur in rain patterns which increase flood and drought risks.
Deforestation also has serious negative repercussions for biodiversity. Animals depend on forests for shelter, food and other essential resources; as forests are cleared away they move closer to humans and pose greater health risks; furthermore it reduces ecosystem resilience against disasters like wildfires or hurricanes.
Deforestation accounts for 12-20% of global greenhouse gas emissions. It is most frequently linked to agricultural expansion; however, other causes include urbanisation and infrastructure development.
3. Livestock
Livestock (including cattle raised for meat, dairy and other products, goats, sheep and pigs) are an important global source of greenhouse gases. Together they produce an extremely large proportion of methane with 23 times greater warming potential than CO2, and 296 times as much nitrous oxide production.
Liveland emissions are estimated to account for 14.5% of global anthropogenic greenhouse gas (GHG) emissions, including both direct emissions from enteric fermentation, manure management, feed production and energy use as well as indirect ones that result from land use changes such as turning forest or grassland into fields for livestock agriculture or energy use.
Estimates of livestock-related emissions can be highly variable, with most variations stemming from differences in assumptions about which sources should be included and how best to calculate them. For instance, whether greenhouse gasses that impact climate differently are converted into carbon dioxide-equivalent (CO2-eq) measurements depends on whether their mass is measured as tonnes or as their global warming potential over 100 years.
People contribute significantly to climate change through unchecked fossil fuel burning and the destruction of forests, wetlands and other natural carbon sinks that help mitigate greenhouse gases in the atmosphere. This has resulted in an exponentially increasing concentration of atmospheric greenhouse gases leading to global average temperature increases referred to as climate change.
4. Nitrous oxide
Greenhouse gases (including carbon dioxide, methane and nitrous oxide ) in Earth’s atmosphere trap heat and prevent it from escaping into space, known as “greenhouse gases”. All three can be produced naturally or by humans through various activities.
Nitrous oxide emissions result from the combustion of fossil fuels, organic waste and vegetation as well as certain agricultural practices, leading to smog formation which poses great danger to our health and contributing to acid rain which damages water resources.
An eruption from a volcano releases sulfate particles into the stratosphere that combine with water vapor to form sulfuric acid (H2SO4) which then mixes with aerosols before being carried by wind around the world, acting as climate forcing agents and warming its surface.
Methane is a greenhouse gas emitted when livestock are raised and coal, natural gas and oil are extracted from the ground. Organic waste decomposing in landfills also releases methane that contributes significantly to global warming. Although methane remains in the atmosphere for less time than carbon dioxide does, its effect still makes an impactful statement about global climate change.
5. Water vapour
Water vapour is a key greenhouse gas in Earth’s atmosphere, trapping heat and slowing its escape into space. Furthermore, humidity–the presence or absence–of water vapour in the air affects how atmospheric radiation absorbs or scatters within its environs.
Air temperatures that are warmer can hold more water vapour, and as climate warms this increase is magnified. But due to its short lifetime in the atmosphere, water vapour tends to act more as an amplifier rather than a driver of global warming.
Human activities also generate other greenhouse gasses that contribute to climate change. Deforestation releases carbon dioxide into the atmosphere while planting crops and rearing livestock emit methane, nitrous oxide and fluorinated gases such as hydrofluorocarbons (HFCs), perfluorocarbons (PFCs) and sulfur hexafluoride (SF6) from equipment used to cool buildings, fridges and cars.
Natural factors, like solar activity, have an impactful influence on Earth’s climate; however, human emissions of greenhouse gases such as carbon dioxide, methane, nitrous oxide chlorofluorocarbons and water vapour arguably exert more of an effect. Without them Earth would be 33 degrees centigrade cooler today and climate change driven by an increase in atmospheric CO2 and other long-lived greenhouse gases is what is driving climate change.
6. Changes in the oceans
The ocean serves to regulate global climate by moderating temperature, controlling rainfall and mitigating droughts and floods. Furthermore, as Earth’s largest carbon sink it absorbs excess heat energy generated from greenhouse gas emissions trapped within our climate system and has caused it to warm further through feedback loops which continue to drive this increase in temperature.
As well as absorbing excess heat energy, the ocean also releases oxygen into the atmosphere through photosynthesis, which takes place among algae and microorganisms living near surface water. When organic material produced through photosynthesis sinks to the ocean floor it undergoes bacterial decomposition producing methane gas which acts as an extremely potent greenhouse gas and nitrous oxide which has 30 times more potency than carbon dioxide in climate regulation.
Human activities have increased the levels of atmospheric greenhouse gases, particularly carbon dioxide. Furthermore, this activity has decreased the ability of natural carbon sinks like forests and wetlands to absorb carbon. Such changes are threatening marine biodiversity as well as millions of people who rely on fisheries for sustenance; contributing to sea level rise that has resulted in serious flooding problems in many locations around the world.
7. Changes in the atmosphere
Every year, Earth’s vegetation produces and absorbs approximately 200 billion metric tons of carbon dioxide, with human activities, particularly fossil fuel combustion adding another 7 billion. As such, atmospheric concentrations are now higher than ever in its 800,000-year history.
Natural processes produce and dispose of greenhouse gases like CO2, as well. Plants release it during photosynthesis; when dead animals decompose, their decay releases it back into the atmosphere – these natural cycles keep carbon dioxide levels relatively steady.
Human activities have produced so much additional carbon dioxide into the atmosphere that it no longer forms part of nature’s cycle, something scientists can recognize from how different the air’s carbon is; scientists can see it because radioactive forms from fossil fuel combustion have altered it further.
Geological records reveal the fact that climate has fluctuated naturally throughout history, often over thousands or millions of years. Today’s global warming, however, is happening much more quickly than can be explained by natural causes alone; its patterns can be clearly seen in climate records.
