Global warming is a serious environmental issue that has been gaining attention in recent years. It refers to the long-term rise in temperatures of the planet’s atmosphere, which can cause drastic changes to our climate and ecosystems.
This phenomenon has been going on for centuries, but its effects have become more pronounced over the last hundred years due to human activities such as burning fossil fuels.
Fossil fuels are substances like coal, oil and natural gas that release large amounts of carbon dioxide when burned, leading to an increase in Earth’s atmospheric temperature known as the “greenhouse effect”.
As human population growth continues to surge, so does our dependence on these non-renewable energy sources – resulting in further damage to our planet’s delicate balance.
Global Warming Vs Climate Change
Global warming and climate change are two terms that are often used interchangeably, but they have distinct meanings. Global warming is an increase in the Earth’s average surface temperature caused by emissions of greenhouse gases, such as carbon dioxide (CO2), from burning fossil fuels and other human activities.
Climate change refers to the long-term changes in temperature, precipitation, wind patterns and other aspects of Earth’s climate. These changes are caused by global warming, among other factors.Climate change can have a wide range of impacts on our lives.
It can cause rising sea levels due to melting ice sheets and glaciers, as well as more extreme weather events like floods, droughts, and heat waves. Climate change can also cause changes in the growing season and affect plant and animal populations.
Global Annual Temperature Is On The Rise
The rise of global annual temperature has been a topic of concern for many years, and its effects are only becoming more evident every day. The average global temperature has risen about 2 degrees Fahrenheit since 1880 when accurate record keeping begins.
From 1981 onwards, the rate of increase has more than doubled to 0.18 degrees Celsius (0.32 degrees Fahrenheit) per decade. This warming trend is largely due to the increase of greenhouse gases in our atmosphere which trap heat and make Earth’s climate more volatile. The rise in temperature has already had a dramatic effect on our climate.
We must limit global warming to 1.5 degrees Celsius by 2040 in order to prevent the most catastrophic effects of climate change from ravaging our planet and its inhabitants.
Without efforts to mitigate this warming, we will experience devastating droughts, floods, rising sea levels, coastal erosion, extreme weather events, altered patterns of agriculture, more frequent and extreme heat waves, ocean acidification, biodiversity losses, and a host of other impacts that will disrupt the lives of people around the world.
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Greenhouse Effect
The greenhouse effect is a phenomenon caused by certain gases in the atmosphere, such as carbon dioxide, methane, and water vapour, which trap heat from the sun and keep it close to the Earth’s surface. This trapped heat causes temperatures to increase, leading to climate change.
These greenhouse gases are carbon dioxide, chlorofluorocarbons, water vapour, methane, and nitrous oxide. Over time, the increase in atmospheric heat has led to a rise in the average global temperature, which is commonly referred to as global warming.
Concentration of heat-trapping gases has substantially increased since preindustrial times and is at levels not seen in at least 800,000 years, according to the Intergovernmental Panel on Climate Change (IPCC), which is the leading international scientific body studying the subject.
Since 1750, the burning of dirty fossil fuels has mainly led to an increase of 40% in carbon dioxide (which is the primary factor in climate change), 20% in nitrous oxide, and a staggering 150% in methane.
According to the IPCC, it is highly probable that the increase in global temperatures since the 1950s is primarily caused by these emissions. Additionally, deforestation and forest degradation have also significantly contributed to global carbon emissions.
Key Greenhouse Gases
Most of the warming since 1950 has been caused by human emissions of greenhouse gases. They are produced by burning fossil fuels, deforestation, agricultural activities such as crop fertilisation and livestock production, as well as industrial processes.
Carbon Dioxide
Carbon dioxide (CO2) is the primary greenhouse gas contributing to recent climate change. Carbon dioxide enters the atmosphere through burning fossil fuels, solid waste, trees, and other biological materials, and as a result of certain chemical reactions, such as cement manufacturing.
Processes such as plant and animal respiration, volcanic eruptions, and ocean-atmosphere exchange result in both absorption and emission of carbon dioxide as part of the carbon cycle.
Burning of fossil fuels such as oil and coal, as well as natural gas, is the primary way in which human activities contribute to the increase of CO2 levels in the atmosphere.
These fuels are commonly used for transportation, heating, and generating electricity. Another way human activity contributes to CO2 levels is through the production of cement.
Burning of forests and the clearing of land are other human-made sources that release carbon. These activities result in about 7 billion tons of carbon being released into the atmosphere each year.
Anthropogenic emissions are estimated to be responsible for nearly one-third of all global CO2 emissions, and the amount of carbon being released into the atmosphere has increased significantly since the beginning of the industrial revolution.
Water Vapour
Water vapour is a type of gas that helps trap heat. Warmer air has more water vapour than cooler air. As the earth gets hotter, there will be more water vapour in the air, making the earth even hotter.
When the surface temperature increases, more water molecules from the surface are converted into vapour. This increase in evaporation leads to a higher concentration of water vapour in the lower atmosphere, which is capable of absorbing longwave radiation and emitting it downwards.
Methane
Methane production from natural sources occurs as a result of microbial breakdown of organic matter in wetlands, landfills and other anaerobic environments. On the other hand, anthropogenic sources of methane include coal mining, natural gas and petroleum systems, livestock farming and rice cultivation.
Natural sources of methane are responsible for a significant fraction of atmospheric methane levels. Wetlands, both tropical and northern, are major contributors to the global atmospheric methane budget.
Methane-oxidising bacteria that feed on organic material consumed by termites is another source of natural methane.
Volcanoes, seepage vents of the seafloor in regions rich with organic sediment, and methane hydrates trapped along the continental shelves of the oceans and in polar permafrost also contribute to the global methane budget.
Methane is primarily absorbed by the atmosphere through a reaction with the hydroxyl radical (OH) in the troposphere, which leads to the production of CO2 and water vapour (H2O). This process occurs naturally and is the main way in which methane is removed from the atmosphere.
Methane is also absorbed by soil where bacteria oxidise it. Once methane enters the stratosphere, it is no longer a concern because it gets destroyed.
Human activity is causing the concentration of CH4 to increase at a rate faster than natural sinks can balance, just like with CO2. About 70% of total yearly emissions come from human sources, which causes a significant rise in methane concentration over time.
Human activities that contribute to the presence of methane in the atmosphere include rice cultivation, livestock farming, burning coal and natural gas, burning biomass, and organic matter decomposition in landfills.
Future trends of methane emissions are particularly hard to predict since there is an inadequate knowledge of the climate feedbacks related to CH4 discharges. Additionally, it is challenging to foresee how population increases could alter the way livestock are raised, rice cultivation is done, and energy usage influences CH4 emissions.
Nitrous Oxide
Nitrous oxide, commonly known as N2O, is a powerful greenhouse gas produced mainly through agricultural activities and natural biological processes. Fossil fuel burning and industrial processes also contribute to its production.
Concentrations of N2O have risen dramatically since the start of the Industrial Revolution, making it an important factor in climate change. The effects of nitrous oxide are far-reaching and threaten our environment and health. As such, understanding and addressing this gas is essential for protecting our planet’s future.
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Other Greenhouse Gases
Tropospheric ozone (O3)
Tropospheric ozone (O3) is an extremely potent greenhouse gas that has a relatively short atmospheric lifetime. It is created when nitrogen oxides and volatile organic compounds, which are emitted from sources such as automobiles, power plants, and various industrial and commercial facilities, react with sunlight in the air.
Not only does O3 trap heat, but it can also cause respiratory health problems, damage crops and ecosystems, as well as other environmental issues.
Water Vapour
Water vapour is another important greenhouse gas that has a direct impact on the Earth’s climate. It works as a “feedback mechanism” in that when the atmosphere warms up due to increased concentrations of other greenhouse gases, water vapour can trap more heat.
This further amplifies the warming effect and causes temperatures to rise even more. As global temperatures increase, more water vapour is able to stay in the atmosphere, creating a positive feedback loop.
This increased water vapour further amplifies the effect of other greenhouse gases and can lead to even more drastic changes in climate over time.
F-gases
F-gases, such as chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs) and sulphur hexafluoride (SF6), are frequently used in a variety of applications, including as coolants, foaming agents, fire extinguishers, solvents, pesticides and aerosol propellants.
Unlike water vapour and ozone, these F-gases have exceptionally long lifespans in the atmosphere and their emissions can significantly impact climate conditions for many decades or even centuries.
Land-use Change
Change in land use can affect the climate in various ways. One of the most significant impacts is altering Earth’s albedo, which refers to its surface reflectivity. When forests are cleared to make way for development, the darker surfaces that replace them absorb more energy from the sun, resulting in an increase in temperatures at the surface of the Earth.
In addition to changing albedo, land-use changes also impact climate in other ways. Deforestation can lead to increased levels of carbon dioxide in the atmosphere, resulting in higher temperatures.
Degraded soils from farming, overgrazing and other land-use activities can also degrade soil fertility and increase the amount of dust and debris in the air, both of which can affect climate.
Finally, altering land use can also change the amount of water that is available to plants and animals.
For example, urban development often leads to a decrease in soil moisture, resulting in drier conditions. These changes to land use can have major impacts on the environment and can even contribute to global climate change.
Deforestation in tropical regions has an immense effect on the carbon sequestration process. Carbon sequestration is the process of storing carbon in underground cavities, biomass, and other areas rather than in the atmosphere.
By doing so, it helps to reduce global warming because fewer greenhouse gases are released into the atmosphere. In a tropical area, plants absorb carbon dioxide from the atmosphere to help reduce global warming.
When trees and other vegetation are cut down due to deforestation, there is an overall decrease in the number of plants available for carbon absorption.
In addition, when fallen trees, shrubs, and other plants are burned or decomposed, they release their stored carbon back into the atmosphere as carbon dioxide which further increases concentration of greenhouse gases in the atmosphere.
Climate Feedbacks
Climate feedbacks are like a game. When global warming happens, the climate feedbacks respond by either slowing it down (negative feedbacks) or making it faster (positive feedbacks).
Most significant positive feedback appears to be caused by water vapour. When the Earth heats up, it causes an increase in the rate of evaporation, which in turn leads to more water vapour in the air. This increase in water vapour acts as a greenhouse gas, leading to further warming.
The rapid melting of Arctic sea ice is one of the most concerning and visible effects of global climate change. It is also another example of positive climate feedback. As temperatures rise, sea ice retreats, and the darker surface of the sea beneath absorbs more sunlight than ice.
This leads to an increase in total warming, and less snow cover during warm winters has a similar effect. All of these factors contribute to a warming climate, amplifying the effects of global climate change.
Clouds can have both a warming and cooling effect on the climate. They reflect sunlight during the day, which cools the planet. At night, they slow down the escape of heat to space, making cloudy nights warmer than clear nights.
Climate change can have a significant impact on clouds, resulting in changes to their coverage, altitude, and reflectivity. These modifications can then either act to reinforce the initial climate change (positive feedback) or counter it (negative feedback).
The net effect of these changes is likely an amplifying, or positive, feedback due mainly to increasing altitude of high clouds in the tropics, which makes them better able to trap heat, and reductions in coverage of lower-level clouds in the mid-latitudes, which reduces the amount of sunlight they reflect.
Scientists have not been able to ascertain the magnitude of this feedback due to the complex nature of cloud/climate interactions.