Greenhouse gas basics

What is the number one greenhouse gas?

CO2 is the primary greenhouse gas - accountable for app. 75% of greenhouse gas emissions in 2018.

Based on data from ClimateWatch approximately 75% of the world’s greenhouse gas emissions are from CO2 – and this is often the main associated synonym with greenhouse gas emissions. CH4, F-gas, and N2O can have a potent effect in the short term according to ClimateWatch (read more here).

Overview of greenhouse gas emissions by sector

Hannah Ritchie and Max Roser (2020) - "CO₂ and Greenhouse Gas Emissions". Published online at Retrieved from: '' [Online Resource]

From a product engineering point of view which sectors can be influenced by design?

The most relevant sectors are pointed out below:

    • Electricity and heat
    • Transport – to some degree (either by logistics or improving the products that account for the emissions)
    • Manufacturing and construction (the manufacturing part especially)
    • Industry
    • Waste (especially production scrap)
      • According to the material efficiency (“% of materials converted to products & co-products”) for crude steel is app. 98%. 
    • Other fuel combustion
    • Aviation and shipping (optimization of products – performance and materials)

Another, more detailed view, from “Our World in Data” (2016):

The interesting groups from a product development point of view are:

    • Iron and steel (7.2%)
    • Machinery (0.5%)
    • Other industry (10.6%)
    • Transport (16.2%)

In total – approximately 33% of global emissions.

According to “Our World in Data” approximately 25% of the global greenhouse gas emissions arise from food production – which is not directly impacted by mechanical engineering or product development. 

How is the greenhouse gas split between countries?

The big picture - where does the main emissions arise from?


China, United States, EU and India account for more than 50% of the worlds greenhouse gas emissions.

A look at the trend over time…

As countries industrialize, historically, CO2 emissions rise – meaning that a demand for green product design is a part of breaking this trend. 

Learn more about CO2 and link to product development

What is the global material impact on greenhouse emissions?

From a mechanical engineering point of view, the effort in material substitution from CO2 heavy to CO2 light materials is interesting.

From the chart below (estimates by RD8) it is seen that:

    • Plastics drive app. 2% of global CO2 emissions
    • Crude steel drive app. 7% of global CO2 emissions
    • Aluminium drive app. 2% of global CO2 emissions

Converting the annual production of these 3 material groups into CO2-neutral alternatives would drive an approximate 10% reduction in global CO2 emissions.

RD8 analysis


[1]: [Source: Hannah Ritchie and Max Roser (2020) – “CO₂ and Greenhouse Gas Emissions”. Published online at Retrieved from: ‘’]

[2]: Source: Greenhouse gas emissions and natural capital implications of plastics, (including biobased plastics), Eionet Report – ETC/WMGE 2021/3 , European Topic Centre on Waste and Materials in a Green Economy, May 2021

[3]: – 2018 data

[4]: – 2018 data

[5]: – November 2019

Learn more about green material substitution

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