When hydrogen helps climate change – and when it doesn’t.

Hydrogen is hailed as a climate hero because there are no direct carbon emissions (or associated heat) to worry about when used as fuel in buses or steel mills. As the world tries to reduce our fossil fuels, there may be a lot of new demand for this carbon-free energy source.

But how hydrogen works can determine how important it is to the climate. That’s where the rainbow comes in. (I’ve included an at-a-glance chart below so you can decipher all these colors.)

Last week, the European Commission issued rules that define what hydrogen means, in other words, what does hydrogen mean. green. Last week in science there was an amazing story about what happened naturally. GoldHydrogen.

So let’s dive into the hydrogen rainbow and explore where this future fuel might come from.

What do we need hydrogen for?

We use a lot of hydrogen today: global demand is 94 million metric tons in 2021. Much of it was used for oil refining, as well as for the production of ammonia (for fertilizer) and methanol (for chemical production).

That may change in the future, as it is a good substitute for fossil fuels in transportation, heavy industry and other sectors. If countries continue to enter the climate By 2030, hydrogen demand could reach 130 Mt, and a quarter of this will be for renewable uses.

The problem is that today, creating hydrogen in great quantities requires fossil fuels, usually natural gas. In the so-called “grey” hydrogen production, natural gas reacts with water, producing hydrogen gas and eliminating carbon emissions.

But it doesn’t have to be that way. For one thing, we can try to capture carbon emissions from the production of hydrogen from fossil fuels (this method is called blue hydrogen). This is a very controversial approach, as carbon capture is expensive and does not always work efficiently.