<p>I have an ODIAC Global CO<sub>2</sub> emission dataset. The dataset is provided in netCDF (.nc) format and the resolution of the dataset is 1x1 degree. The unit of the dataset is gC/m<sup>2</sup>/day. I need to convert it into Tonnes.
The approach I am following is as follows:</p>
<p>Suppose we have 7 gC/m<sup>2</sup>/day CO<sub>2</sub> emission for a cell/pixel/grid unit. As the resolution of the cell is 1x1 degree we need to convert it to m<sup>2</sup>.</p>
<p>1x1 deg = 111000 × 111000 m<sup>2</sup> = 1.232×10<sup>10</sup> m<sup>2</sup> (Approximately 1 deg = 111 km)</p>
<p>7 gC/m<sup>2</sup>/day = 7 × 1.232 × 10<sup>10</sup> = 8.624 × 10<sup>10</sup> gC/day = 8.624 × 10<sup>4</sup> tonnes/day (1 Tonne = 10<sup>6</sup> g)</p>
<p>Is it correct approach? I am confused about how to deal with the time unit.</p>

CC BY-SA 4.0
2021-05-17T12:02:54.570Z
Your last sentence is essentially correct, i.e. your question is incomplete. You can *never*  convert between different unit types, so your question needs a time scale. I think depositions in (mega)tonnes are usually expressed *per year*. In that case, multiply by 365
Jan Doggen
CC BY-SA 4.0
2021-05-19T08:32:50.667Z
You **cannot** reliably convert between degree and metric units when it comes to distance/area measurements. While one degree at the Equator is about 110 km wide from East to West, this distance shrinks to less than 40 km at the Polar Circle. Your first step **MUST** be to convert your data to EPSG:3857, a global CRS using `m` as unit of measurement. This still is wildly inaccurate, but not as astronomically as assuming one degree equals always 110 km.
Erik
<climate-models><co2><greenhouse-gases><emissions>
How to convert CO2 emission from gC/m2/day to Tonnes?
Farhan Mustafa
# How to convert CO2 emission from gC/m2/day to Tonnes?

(Asked by: username_0 on 2021-05-16)

I have an ODIAC Global CO2 emission dataset. The dataset is provided in netCDF (.nc) format and the resolution of the dataset is 1x1 degree. The unit of the dataset is gC/m2/day. I need to convert it into Tonnes.
The approach I am following is as follows:

Suppose we have 7 gC/m2/day CO2 emission for a cell/pixel/grid unit. As the resolution of the cell is 1x1 degree we need to convert it to m2.

1x1 deg = 111000 × 111000 m2 = 1.232×1010 m2 (Approximately 1 deg = 111 km)

7 gC/m2/day = 7 × 1.232 × 1010 = 8.624 × 1010 gC/day = 8.624 × 104 tonnes/day (1 Tonne = 106 g)

Is it correct approach? I am confused about how to deal with the time unit.

**Tags:** climate-models, co2, greenhouse-gases, emissions

> **Comments:**
> **username_1**: Your last sentence is essentially correct, i.e. your question is incomplete. You can *never*  convert between different unit types, so your question needs a time scale. I think depositions in (mega)tonnes are usually expressed *per year*. In that case, multiply by 365  
> **username_2**: You **cannot** reliably convert between degree and metric units when it comes to distance/area measurements. While one degree at the Equator is about 110 km wide from East to West, this distance shrinks to less than 40 km at the Polar Circle. Your first step **MUST** be to convert your data to EPSG:3857, a global CRS using `m` as unit of measurement. This still is wildly inaccurate, but not as astronomically as assuming one degree equals always 110 km.  

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## 0 answers

