Question: Hello! I would like to know: Have you considered the impacts of burning hydrogen in replacement of carbon dioxide? For example- reduced insulation due to lowered CO2 levels since it is a greenhouse gas, The increased production of clouds due to production of water vapour (H2O) as a result of burning hydrogen, The changes in the hydrological cycle, for example more clouds will increase albedo and reflect more UV light away from earth further lowering temperatures, Would less water be stored in plants and soil? (Assuming the hydrological cycle is in a dynamic equilibrium, if there was more atmospheric water vapour, there would be less H2O in soil or plants) Would this affect the income for agricultural workers? How would this impact the economy, and food sources? (If there was a reduced soil fertility due to lower water storage, crop yield will be lower and harvest would be affected) Would it be more beneficial to focus on reducing methane production, since it would have a more significant impact on temperature? Thank you !!

John Grasmeder answered on 14 Jun 2023:

Hello Liz! I don’t know about burning hydrogen to replace CO2 but I do know about burning hydrogen to replace burning natural gas (methane, CH4).
There are both problems and opportunities in doing this. Some of the problems:
1. It takes a lot of energy make hydrogen, and today most of this energy is from coal, oil and gas. Most hydrogen itself is also generated from coal, oil and gas today, not from water.
2. Hydrogen is difficult to handle, store and move around. A big articulated truck can carry at most only 300 kg of hydrogen under pressure. To make it a liquid it has to be cooled to -253°C and compressed to a high pressure, both of which need lots of energy to do.
3. Hydrogen is very explosive
4. Hydrogen can make the metal pipes used to transport it very brittle, so they can crack and leak (see point 3)
5. Hydrogen burns in a very different way to methane – for example, the flame burns hotter which can produce nitrogen oxide (NOx) pollution which is a type of indirect greenhouse gas; the flame burns faster which means the gas has to be pumped faster; and the flame produces lot of non-polluting water, but in some cases, so much that it can make existing boilers go rusty very quickly.
But the big benefit is, if it can be made with renewable energy and burned at a low enough temperature so that no NOx is produced, it burns without causing pollution.