Causes: Hydrogen
The many colours of hydrogen: a fossil-fuel scam
Levels of hydrogen in the atmosphere have jumped by 60% since pre-industrial times, underscoring the dramatic impact fossil fuel burning has had on the planet’s atmospheric composition. Although hydrogen is not a greenhouse gas, it has an indirect warming effect through reactions with other molecules. – New Scientist 2025
Increasing levels of atmospheric hydrogen have led to “indirect” warming of 0.02C over the past decade. – Carbon Brief 2026
The greenhouse gas footprint of blue hydrogen is more than 20% greater than burning natural gas or coal for heat and some 60% greater than burning diesel oil for heat. – Howarth et al 2021
Hydrogen (H) is the most abundant element in the universe; it makes up 70% of the sun and 90% of Jupiter. On Earth, it is present as a gas in the atmosphere only in tiny amounts – less than 1 part per million by volume. Any pure hydrogen (H) that enters the atmosphere quickly escapes the Earth’s gravity into space. It is nevertheless abundant when combined with other molecules, like oxygen, to form compounds like water (H2O) and carbon to produce methane (CH4). In some underground locations, due to the chemical interaction between certain rocks and groundwater, it can be found as gas.
In its pure elemental form, hydrogen can be burned to generate energy. Because the only by-product is water, it’s a clean source of energy that does not contribute to climate change. However, to produce hydrogen requires separating it from other compounds through electrolysis, which creates the greenhouse gases carbon dioxide CO2 and methane CH4. Moreover:
The ‘colours’ of hydrogen
These refer to the type of fuel used to extract hydrogen through electrolysis:
- Blue: invented by the fossil-fuel industry to collectively greenwash three different processes while claiming that some CO2 from these processes is captured and stored underground, with no evidence that the CO2 can’t escape (see Carbon Capture technologies and Video 1):
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- Black: burning back coal
- Brown: burning lignite or brown coal
- Grey: burning methane
- Red or Pink: uses nuclear power
- Green: uses any form of green energy: solar, wind, waves etc.
Naturally occurring hydrogen also requires significant power to mine and extract:
- Gold or White: hydrogen found in its natural state in underground reservoirs
- Orange: produced through directed reactions of certain rock formations
However there is also good news. A chemical process has been found whereby the production of hydrogen can remove CO2:
…hybrid chemo-microbial systems utilizing waste feedstocks can outperform electrolytic hydrogenation and achieve carbon-negative outcomes. – White et al 2026
