How to Calculate CO2 Emissions vs Sequestration

Carbon dioxide (CO2) is a colorless acidic gas that occurs naturally in the earth’s atmosphere or through human activity such as fuel combustion. The amount of CO2 released can be determined by calculating greenhouse gas equivalencies. One key factor about trees is that they sequester carbon through a process known as carbon sequestration.

Carbon sequestration is a process by which trees capture and store atmospheric carbon dioxide, thus reducing the amount in the atmosphere. As you may know, trees and generally plants use carbon dioxide during the day in their biological processes. Different tree species have different rates of carbon sequestration. Research conducted by Eco Matcher indicates that plated trees sequester carbon dioxide at an average rate of 25 kilos per tree every year.

A single tree sequesters about 250 kilos in its lifetime if it’s not cut down, which is a major issue of debate and concern globally as the number of forest cover keeps decreasing daily. With that said, you can calculate the amount of CO2 sequestration in every tree using the methods we’ve outlined below.

Read on to understand how to calculate CO2 emissions vs sequestration!

How CO2 Sequestration Is Calculated

Below is a step-by-step guide on how to estimate the carbon sequestration of a single tree:

Step 1: Ascertain the total green weight of a tree

The green weight of a tree is basically the weight it carries when alive. The green weight of a tree is calculated using the following algorithm.

H= Height of the green tree in feet

D= Diameter of the trunk in inches

W=Weight of the tree above ground in pounds

For trees with D<11,

Weight above ground (W) = 0.25 D2H

For trees with D>11,

Weight above ground (W) = 0.15 D2H

Depending on the tree species you are dealing with, the coefficient used such as 0.15 could change, and the variables D2 and H raised to an exponential below or above one. The primary system weighs approximately 20 percent as much as the above-ground weight of a tree. This means, when determining the total green weight of a tree, you ought to multiply the above-ground weight by 120 percent (120%).

Therefore,

The total green weight =1.2 and weight above ground (W).

Step 2: Ascertain the dry weight of the tree

This usually relies on the extension publication done by the University of Nebraska. The publication contains a table that shows the average weights for various species of trees. With all species considered, an average tree has 27.5 % moisture and 72.5% dry matter. Therefore, to establish the tree’s dry weight, multiply 72.5% with the weight of the tree. 

The total dry weight = 0.725 * W total green weight

Step 3: Establish the weight of carbon in the tree

The average amount of carbon available in a tree is approximately 50% of the tree’s total volume. Therefore, to establish the weight of carbon in the tree, multiply the total dry weight of the tree by 50%. 

Weight of carbon in the tree = 0.5 * total dry weight

Step 4: Establish the weight of C02 sequestered in the tree

Carbon dioxide is a combination of different molecules (Two molecules of oxygen and one carbon molecule). The atomic weight of oxygen (O2) is 16 (u), while carbon is 12 (u). The weight of CO2 is C + 2 * O = 44. To establish the weight of CO2 in trees, you need to do a ratio of CO2 to C, which is 44/12=3.67. Therefore, to establish the sequestered weight of carbon dioxide in the tree, multiply 3.67 with the weight of carbon in the tree.

Weight of CO2 sequestered in the tree = 3.67 * Weight of carbon in the tree

To determine the weight of CO2 that has been sequestered in a year, divide the weight of CO2 that has been sequestered in the tree by the age of the tree. 

Calculating CO2 Emissions Using the Greenhouse Gas Equivalencies Calculator

The greenhouse gas equivalencies calculator is a simple calculator that helps to convert units of energy to the equivalent figures of carbon dioxide emission anticipated from using the amount. The calculator can help you translate abstract measurements to concrete terms and importantly help you understand annual emissions from households, cars, or power plants. 

The greenhouse gas equivalencies calculator can also be a very useful tool in communicating your greenhouse gas reduction targets, reduction strategy, or other factors aimed at minimizing greenhouse emissions.

The device can be used to convert greenhouse gas emission figures into different types of CO2 equivalent units. These are calculated and reported using global warming potentials (GWPs) from the Intergovernmental Panel on Climate Change’s Fourth Assessment Report. Some of the equivalent units used include:

Gallons of diesel consumed

According to National Program fuel economy standards for model years 2012-2016, there was an agreement to use a common conversion factor of 10,180 grams of CO2 emissions per gallon of diesel consumed. Therefore, to establish the amount of CO2 discharged in grams per gallon of diesel burnt, the kilogram CO2 per heat composition of the fuel can be multiplied by the heat content of the fuel per gallon. The assumption here is that carbon is diesel converted to CO2. 

10,180 g of CO2/gal of diesel = 10.180 Ă— 10-3tons CO2/gal of diesel

Passenger vehicles per year

A passenger vehicle is described as a vehicle with four tires and two axles. The yearly greenhouse gas emissions per passenger car are calculated using the following technique. The amount of gallons of gasoline consumed per car per year is calculated by dividing the average vehicle miles driven by the average gas mileage.

The CO2 released per car per year is calculated by multiplying the fuel consumed by the CO2 per gallon of gasoline. To account for additional emissions such as nitrous oxide and methane, CO2 emissions are divided by the ratio of CO2 emissions to total vehicle greenhouse emissions.

In this case:

8.89 Ă— 10-3 metric tons CO2/gallon gasoline Ă— 11,556 VMT car/truck average Ă— 1/22.5 miles per gallon car/truck average Ă— 1 CO2, CH4, and N2O/0.993 CO2 = 4.60 metric tons CO2E/vehicle /year.

The Importance of Measuring these Emissions

CO2 emission is an important topic to every industry, and the oil and gas industry plays a significant role in greenhouse emissions. This is why it’s important to do calculations right to determine the extent of emissions and come up with contingency measures. These calculations may sound impossible or time-consuming, but very important in the protection of the planet while still making economic sense. Professional companies like Melzer Consulting are helping oil companies and governments with complex CO2 dynamics. If you want to establish the wettability of your oil field, a professional consultant will provide you with the required information and guide you through the process of oil recovery.