# GHG, Calculation of GHG and impact on Climate Change

1-What is GHG?

Greenhouse gases, which is also known as GHGs, are gases in the Earth’s atmosphere that trap heat. During the day, the sun’s rays penetrate the atmosphere, warming the Earth’s surface. At night, the surface cools, releasing heat back into the air. However, some of this heat is trapped by the GHGs in the atmosphere, helping to maintain the Earth’s average temperature of 14˚C (57˚F). Without this natural insulation, the Earth’s temperature would be much colder.

What is Effect of GHG?

Greenhouse gases are those atmospheric components that have a profound influence on the Earth’s energy balance, resulting in greenhouse effect. The well-known of these gases are carbon dioxide (CO2), methane, and nitrous oxide, which are naturally present in the atmosphere in low concentrations. However, since the beginning of the last century, their proportion has increased significantly due to various human-induced sources.

Unfortunately, human activities are drastically altering the Earth’s natural greenhouse effect by releasing unprecedented amounts of greenhouse gases into the atmosphere. Scientists agree that these gases are the primary cause of global warming and climate change.

Since the Industrial Revolution, humans have been emitting larger quantities of greenhouse gases into the atmosphere. In the past century, this amount has skyrocketed, leading to a rapid acceleration of global temperatures over the past 30 years, which are now the highest since records began.

2- How to calculate emission of GHG (Greenhouse gases)?

Every greenhouse gas (GHG) has its own Global Warming Potential (GWP), which is a metric used to measure the amount of heat the GHG can trap in the atmosphere and the expected environmental impact. Specifically, GWPs are calculated by determining the ratio of heat trapped by one unit mass of a particular GHG compared to one unit mass of carbon dioxide over a given period of time.

When managing your air emissions, you may be presented with results in terms of tons of emissions. However, it is important to note that one ton of a certain GHG is not equivalent to one ton of another. Therefore, simply adding up all the tons of GHG emissions does not accurately reflect your carbon footprint.

Furthermore, there are a variety of GHGs to keep track of when reporting emissions. These include: carbon dioxide, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride. By understanding the GWP of each of these GHGs, you can accurately measure and report your emissions and their impact on the environment.

For GHG reporting, we have need to track the following GHG emissions:

1. Carbon dioxide
2. Methane
3. Nitrous Oxide
4. Hydrofluorocarbon gases
5. Sulfur hexafluoride
6. Perfluorocarbon gases

In case of GHG calculation, every GHG has a different GWP (Global Warming Potential), we cannot rely only typical on air emission report to calculate our total GHG output.

The solution should be use each GHG’s individual GWP and use its GWP to translate our air emissions into a common unit that compares and relates all our GHG emissions which is called Co2e. We should   report them as a single combined quantity i.e.CO2e

CO2e puts all our GHG emissions into carbon dioxide, which is considered to have a GWP of 1. Carbon dioxide is used as the reference GHG that all others gases get compared to.

The common method for calculation is

GHG emission = 0.001 * Fuel Usage * High heat value *Emission factor

CO2 e = GWP*GHG emission (tons)

3- How to Measure GHG Emissions by Scope ?

In order to accurately measure GHG emissions by scope, organizations must first identify the profile of the organization’s economic activities from which emissions originate. These activities are then broken down into four broad scopes:

1-Direct (Scope 1) 2- Indirect purchased electricity (Scope 2) 3- Non-power indirect (Scope 3).

Scope 1 includes all direct GHG emission sources owned or controlled by an organization, such as combustion of fuel in boilers, process and fugitive sources.

Scope 2 covers indirect GHG emissions from purchased electricity through third party transmission and distribution providers.

Scope 3 covers other indirect emissions related to the operations of the organization but not otherwise included in Scopes 1 or 2 such as employee air travel and business travel related activities.

To calculate GHG emissions for each scope it is important to track emissions associated with a variety of source categories, taking into consideration different complex processes along with resources consumed or produced within production cycles. Finally, organizations need to use nationally accepted accounting standards such as the Greenhouse Gas Protocol Corporate Accounting and Reporting Standard to ensure accuracy and reliability when reporting on GHG scope emission levels.

4- How ISO Standard useful for deal with GHG ?

As the COP 21 Conference of the Parties of the United Nations Framework Convention on Climate Change (UNFCCC) kicks off, the importance of this year’s talks and negotiations cannot be overstated. With the goal of limiting global warming to 2°C, organizations, regulators, companies, and cities must have the tools to address climate change, reduce greenhouse gas (GHG) emissions, and manage mitigation and adaptation.

Fortunately, the International Organization for Standardization (ISO) has developed a family of standards to help organizations meet this challenge.

1. ISO 14064 and ISO 14065 provide specifications for quantifying, monitoring, and validating/verifying GHG emissions.
2.  ISO 14001 and ISO 50001 promote good practice in environmental and energy management.
3. ISO 14067 outlines the principles, requirements, and guidelines for quantifying and reporting the carbon footprint of products.
4. ISO 14007 and ISO 14008 help organizations determine the costs and benefits of taking action to adapt to climate change.

In addition, ISO is currently developing ISO 14080, a guidance with framework and principles for methodologies on climate actions. This standard will provide guidance on a framework for developing new methodologies, as well as on the use of existing methodologies for climate action and their review, revision, and management to meet stakeholder needs.

With the help of these standards, organizations can take meaningful action to combat climate change and ensure a more sustainable future.