Climate Change – 

What is Climate Change? 

Climate change refers to long-term alterations in temperature, precipitation, wind patterns, and other aspects of the Earth's climate system. These changes may be natural or caused by human activities, especially the emission of greenhouse gases.  

Climate change refers to long-term shifts in temperatures and weather patterns. Such shifts can be natural, due to changes in the sun’s activity or large volcanic eruptions. But since the 1800s, human activities have been the main driver of climate change, primarily due to the burning of fossil fuels like coal, oil, and gas.  Burning fossil fuels generates greenhouse gas emissions that act like a blanket wrapped around the Earth, trapping the sun’s heat and raising temperatures.  The main greenhouse gases that are causing climate change include carbon dioxide and methane. These come from using gasoline for driving a car or coal for heating a building, for example. Clearing land and cutting down forests can also release carbon dioxide. Agriculture, oil, and gas operations are major sources of methane emissions. Energy, industry, transport, buildings, agriculture, and land use are among the main sectors that cause greenhouse gases.

Causes and Effects of Climate Change

Fossil fuels – coal, oil, and gas – are by far the largest contributor to global climate change, accounting for over 75 per cent of global greenhouse gas emissions and nearly 90 per cent of all carbon dioxide emissions.  

As greenhouse gas emissions blanket the Earth, they trap the sun’s heat. This leads to global warming and climate change. The world is now warming faster than at any point in recorded history. Warmer temperatures over time are changing weather patterns and disrupting the usual balance of nature. This poses many risks to human beings and all other forms of life on Earth.

Main Causes of Climate Change: 

Burning Fossil Fuels: 

• Coal, oil, and natural gas are burned for electricity, heat, and transportation.  
• This releases carbon dioxide (CO₂) and other greenhouse gases into the atmosphere.  

Deforestation: 

• Trees absorb CO₂. Cutting them down reduces this absorption and releases stored carbon.  
• Forest loss also disrupts natural climate regulation.  

Industrial Activities:  

• Factories and industries emit large amounts of CO₂, methane (CH₄), and nitrous oxide (N₂O) during manufacturing.  

Agriculture:  

• Livestock (especially cows) produce methane gas.  
• Fertilizers release nitrous oxide.  
• Farming practices can degrade soil and increase emissions.  

Waste Management:  

• Landfills produce methane as organic waste decomposes.  
• Poor waste disposal adds to greenhouse gas levels.  

Use of Aerosols and Chemicals: 

• Some industrial chemicals (like CFCs) damage the ozone layer and affect climate patterns.

Natural causes of climate change 

Some amount of climate change can be attributed to natural phenomena. Throughout Earth’s existence, volcanic eruptions, fluctuations in solar radiation, tectonic shifts, and even small changes in our orbit have all had observable effects on planetary warming and cooling patterns.  

But climate records can show that today’s global warming, particularly what has occurred since the start of the industrial revolution, is happening much, much faster than ever before. According to NASA, “[t]hese natural causes are still in play today, but their influence is too small or they occur too slowly to explain the rapid warming seen in recent decades.” And the records refute the misinformation that natural causes are the main culprits behind climate change, as some in the fossil fuel industry and conservative think tanks would like us to believe.

Human Activity Is the Cause of Increased Greenhouse Gas Concentrations 

Over the last century, the burning of fossil fuels like coal and oil has increased the concentration of atmospheric carbon dioxide (CO2). This increase happens because the coal or oil burning process combines carbon with oxygen in the air to make CO2. To a lesser extent, the clearing of land for agriculture, industry, and other human activities has increased concentrations of greenhouse gases.

How do we know what greenhouse gas and temperature levels were in the distant past? The industrial activities that our modern civilization depends upon have raised atmospheric carbon dioxide levels by nearly 50% since 17502. This increase is due to human activities, because scientists can see a distinctive isotopic fingerprint in the atmosphere.  

In its Sixth Assessment Report, the Intergovernmental Panel on Climate Change, composed of scientific experts from countries all over the world, concluded that it is unequivocal that the increase of CO2, methane, and nitrous oxide in the atmosphere over the industrial era is the result of human activities and that human influence is the principal driver of many changes observed across the atmosphere, ocean, cryosphere and biosphere.

Global Warming

Since the Industrial Revolution, the global annual temperature has increased by a little more than 1 degree Celsius, or about 2 degrees Fahrenheit. Between 1850, when accurate recordkeeping began, and 1980, it rose on average by 0.07 degrees Celsius (0.13 degrees Fahrenheit) every 10 years. Since 1981, however, the rate of increase has more than doubled: For the last 40 years, we’ve seen the global annual temperature rise by 0.2 degrees Celsius, or 0.36 degrees Fahrenheit, per decade.  The result? A planet that has never been hotter. The 10 most recent years are the warmest years on record. And the warmer it gets, the more probable it becomes that we trigger climate tipping points (such as rapid glacier melt or thawing permafrost) that can transform natural systems into entirely different states and lead to more warming.   In 2015, the Paris Agreement codified the recommendation of climate scientists to limit global warming to 1.5 degrees Celsius. Working toward that goal continues to give us our best chance to stave off the worst, most devastating effects of climate change: the extreme droughts, wildfires, floods, tropical storms, and other disasters that are so widespread and costly to both our infrastructure and our health.

Main Causes of Global Warming

Man-made Causes of Global Warming 

Deforestation 

Plants are the main source of oxygen. They take in carbon dioxide and release oxygen, thereby maintaining environmental balance. Forests are being depleted for many domestic and commercial purposes. This has led to an environmental imbalance, thereby giving rise to global warming.  

Use of Vehicles 

The use of vehicles, even for a very short distance, results in various gaseous emissions. Vehicles burn fossil fuel, which emits a large amount of carbon dioxide and other toxins into the atmosphere, resulting in a temperature increase.  

Chlorofluorocarbon

With the excessive use of air conditioners and refrigerators, humans have been adding CFCs into the environment, which affects the atmospheric ozone layer. The ozone layer protects the Earth's surface from the harmful ultraviolet rays emitted by the sun. The CFCs have led to ozone layer depletion, making way for the ultraviolet rays, thereby increasing the temperature of the Earth.

 Industrial Development 

With the advent of industrialization, the temperature of the Earth has been increasing rapidly. The harmful emissions from the factories add to the increasing temperature of the Earth.  In 2013, the Intergovernmental Panel on Climate Change reported that the increase in the global temperature between 1880 and 2012 has been 0.9 degrees Celsius. The increase is 1.1 degrees Celsius when compared to the pre-industrial mean temperature.  

Agriculture 

Various farming activities produce carbon dioxide and methane Gas. These add to the greenhouse gases in the atmosphere and increase the temperature of the Earth.  

Overpopulation

An increase in population means more people breathing. This leads to an increase in the level of carbon dioxide, the primary gas causing global warming, in the atmosphere.  

Natural Causes of Global Warming 

Volcanoes 

Volcanoes are one of the largest natural contributors to global warming. The ash and smoke emitted during volcanic eruptions go out into the atmosphere and affect the climate.  

Water Vapour 

Water vapour is a kind of greenhouse gas. Due to the increase in the Earth’s temperature, more water evaporated from the water bodies and stays in the atmosphere, adding to global warming.

Melting Permafrost 

Permafrost is frozen soil that has environmental gases trapped in it for several years and is present below Earth’s surface. It is present in glaciers. As the permafrost melts, it releases the gases back into the atmosphere, increasing Earth’s temperature.  

Forest Blazes 

Forest blazes or forest fires emit a large amount of carbon-containing smoke. These gases are released into the atmosphere and increase the Earth’s temperature, resulting in global warming.

Effect of Global Warming

Rising Temperatures  

• Average global temperatures are increasing, leading to more frequent heat waves and warmer seasons.

Melting Ice and Glaciers  

• Polar ice caps and mountain glaciers are melting, contributing to rising sea levels.  

Sea Level Rise  

• As glaciers melt and oceans warm (causing water to expand), sea levels rise, threatening coastal areas with flooding.  

Extreme Weather Events

• More intense hurricanes, floods, droughts, and wildfires are occurring due to changing climate patterns.  

Ocean Warming and Acidification  

• Oceans absorb much of the heat and CO₂, causing harm to marine life like coral reefs and fish.