The Paris Agreement on climate change, to which the United States is a signatory, sets an ambitious goal of limiting the increase in global average temperature to 1.5 degrees Celsius above pre-industrial levels. We are about 1.1 degrees higher already, and the world has fallen behind schedule in reducing the production of greenhouse gases sufficiently to attain this goal. Success will require a radical reduction in the burning of fossil fuels and the eventual achievement of net zero carbon emissions by 2050. That’s a tall order.
But thanks to advancing technology, that goal is increasingly attainable. What was once science fiction is now on the visible horizon: commercially viable “green” hydrogen extracted from water as an abundant, clean energy source that leaves essentially no carbon footprint. Investment incentives from many nations including the Inflation Reduction Act in the U.S. are accelerating the development of viable applications and attracting the private capital required for hydrogen to supply a quarter of the world’s energy needs by mid-century.
Hydrogen is the first and simplest element in the periodic table (symbol H), as well as the first to form in the moments following the Big Bang. The name is Greek for “water forming” since it partners with oxygen to form H2O. Hydrogen also has tremendous energy potential and is a constituent of virtually anything that burns, but is typically paired with carbon and releases greenhouse gases like carbon dioxide upon combustion that contribute to climate change. It is commonly used to remove sulfur during oil refining or in producing ammonia and is usually extracted from other hydrocarbons like methane (natural gas) via a process called steam reformation, dispersing carbon into the atmosphere.
But hydrogen can also be extracted by a process called electrolysis that uses electricity to separate the hydrogen and oxygen atoms from ordinary water and renders no carbon gases. Electrolysis is an old technology that has been commercially unviable due to the large amount of electricity required, most of which is produced by burning hydrocarbons. That is changing with the advancement of more abundant renewable sources of electricity.
Scientists classify hydrogen by “colors” according to the source of production. “Grey” hydrogen is the traditional stuff culled from fossil fuels (natural gas, oil, or coal). “Blue” hydrogen is the moniker attached to production from fossil fuels but utilizing some form of carbon capture technology to reduce the footprint by injecting sequestered greenhouse gases into caverns or solidifying and burying the carbon byproducts.