Greenhouse Gas (GHG)

The gases that have the property of absorbing infrared radiations from the Earth's surface and radiating it back to the Earth's surface, leading to a Greenhouse phenomenon, are known as Greenhouse gases. Methane, Carbon Dioxide and Water Vapour are some of the leading examples of Greenhouse gases. These gases affect Earth's energy balance and are found to occur naturally. However, urbanisation and industrialisation have significantly increased the concentration of these gases in the atmosphere. Before going into details of the subject, let us first clear our understanding of the greenhouse effect.

What is the Greenhouse effect?

Earth's surface takes and absorbs solar radiations that come from the Sun. The Earth absorbs part of these radiations, and the remaining energy is reflected as long-wave heat radiations. The reflected radiations are partially absorbed by greenhouse gases present in the atmosphere and reflected the Earth, which heats Earth's lower atmospheric layers along with Earth's surface. The complete process is referred to as the "Greenhouse Effect". This process is responsible for maintaining a comfortable temperature on the Earth's surface.

Why is the Greenhouse effect taken very seriously nowadays?

Since the entire Greenhouse phenomenon is a natural process that is continuously going for ages. Several important questions like - why are we more concerned about these gases nowadays? Why every country is planning to combat Greenhouse gases and why governments across the globe are shifting towards green energy?, have been raised at various national and global platforms. Human-made greenhouse gas is the single answer to all these questions. Man-made greenhouse gases disturbed the ecological balance of the Earth by pumping more greenhouse gases into the atmosphere. Increased urbanisation, industrialisation, and increased use of fossil-fuel-driven vehicles have supplied an enormous amount of carbon dioxide, carbon monoxide, methane, and other greenhouse gases, which has significantly increased the temperature of Earth.

However, the installation of air conditioners is a solution to this problem which can reduce the room temperature and make humans comfortable, but the problem is not limited to the room temperature alone. Man-made greenhouse gases have disturbed the Earth's temperature equilibrium. The process is leading to global warming and is causing climate change.

Global Warming and Climate Change:

Global warming and climate change are interchangeably used to address the aspects of climate change. But it must me keep in mind that both the terms are entirely different, however, related to each other. Global warming refers to the rise in temperature due to an increase in greenhouse gases in the atmosphere whereas, climate change is the long term change in Earth’s temperature that includes wind patterns, temperature and precipitation.

What are the long-term impacts of climate change?

Besides the common impacts of global warming, we discussed in the previous section, scientists have also predicted some regional impacts of climate change. Let us have a brief look at these impacts:

Scientists believe that increase in global warming will decrease the snow cover of western mountains in North America.
Latin America’s eastern Amazonia region may face gradual replacement of tropical forest by savannah. Some species may extinct, with significant biodiversity loss is anticipated.
Europe may face risks of inland flash floods with increased coastal erosions and flooding. The region will also face glacial retreats will losses in crop productivity.
The Asian region is expected to face freshwater challenges, with coastal regions more prone to increased flooding by 2050. The region is also anticipated to face enhanced death rates due to water-associated diseases.
African region may face freshwater challenges water scarcity for agriculture.

Which gases are the biggest contributor to greenhouse emissions?

As per US Environmental Protection Agency, Carbon Dioxide, Methane, Nitrous Oxide and Fluorinated gases are the main contributors to greenhouse gas emissions. Let us try to understand the main sources of all these gases.

Carbon Dioxide: Carbon dioxide is the main source of global warming, which contributed to around 81 per cent of emission levels, as per 2018 data. The main sources of carbon dioxide are fossil fuels, i.e. natural gas, coal, oil, manufacturing of cement. Carbon dioxide is the main source of the greenhouse effect.
Methane: Methane is another major contributor to global warming, which contributes around 10 per cent of greenhouse gas emission. Production of coal, oil and natural gas are the main sources for the generation of methane gas. Livestock and agricultural practices also contribute to the generation of methane gas.
Nitrous Oxide: Nitrous Oxides contribute around 7 per cent towards greenhouse gas emission. Nitrous oxide is produced during industrial and agricultural activities. Treatment of wastewater, burning of fossil fuels and solid wastes are some other sources of nitrous oxide.
Fluorinated Gases: Perfluorocarbons, nitrogen trifluoride, hydrofluorocarbons and sulphur hexafluoride are few examples of fluorinated gases, which are generally produced by various industrial processes. Since these gases are potent greenhouse gases, so their little concentration has a large effect on the greenhouse effect. These gases contribute around 3 per cent of greenhouse gas emissions.

How can the world tackle greenhouse emissions?

There are numerous measures to combat greenhouse emission challenges. Few of the measures are now strictly followed by the world to reduce the emission of greenhouse gases. Let's have a look at the following measures:

A ban on the extraction of fossil fuels
Shifting on renewable energy sources, dodging fossil fuels
Phase-out of coal-driven power plants
A switch on electric vehicles and impose a ban on Internal Combustion Engines
Modification of buildings to become energy efficient
Planting more and more trees
Using more energy-efficient devices and gadgets
Spreading awareness to limit the use of greenhouse gases
Recycling waste can also help us to reduce carbon footprints.