We need greenhouse gases – just not at the humdinger levels we’ve created. And it’s not just about what warms the planet - it’s also about what we breathe and drink.’
One of the quickest ways to get a sense of the air quality where you are is to go lichen hunting (it likes to hang out on gravestones, benches, fences etc.) The more of it, the better the air quality. It has no roots - every nutrient has to come from the air. Scientists consider it one of the quickest indicators of air getting cleaner or smoggier.
They act like teeny floating radiators, absorbing sunlight then re-emitting it as heat; they are the nemesis of Arctic sea ice (they land on it and melt them, and make them darker - so they reflect less light)
Hydrogen has one big problem - it doesn’t like to be alone. In nature it hardly ever hangs out solo - it’s always with other things. To use it as fuel, we have to split it, and that process has a ferocious, hangover-level, appetite.– Hydrogen
It stays for about 100 years. Once it’s up there, one of it’s favourite snacks is ozone layer.– Nitrous Oxide
All those forsaken fridges are out there somewhere, with their gas canisters sitting there like tiny unexploded climate bombs. A single molecule of CFC 12, the most common, can hold nearly 11,000 times the heat of carbon dioxide.– CFCs
The earth evolved a system: animals and volcanoes breathe it out, trees and plants suck it in and stick it in the soil, where it is valuable. Into that system we’ve added (to name just a few) nearly 1.5 billion cars, 1.5 billion burping/parping cows, 10 million factories, 186 million tonnes of fertiliser a year and almost everything we do in the western world needs power - most of which still comes from fossil fuels. And of course we’ve taken away most of the trees. Add it up, and it means the atmosphere is pumped full of those little particles that lie about making it hotter.
And once they’re there, they don’t leave for centuries. It is also dissolvable in water and, when it hits the ocean, causes acidification (global warming’s evil twin). We need to stop making them, catch as many as we can of what already exists, and pop the little suckers back in the soil, trees and our other carbon syncs.
They act like teeny floating radiators, absorbing sunlight then re-emitting it as heat; they are the nemesis of Arctic sea ice (they land on it and melt them, and make them darker - so they reflect less light).
Most come from coal-fired power stations and gas or diesel engines but also from cooking and forest fires. Possibly the second naughtiest gas in the room - but it doesn't live long; so, like methane, reducing it can make a quick difference.
And in that lies potentially our salvation, as drastically reducing our methane emissions could be one of the easiest and cheapest ways to slow down global warming between now and 2050.
So what do we need to limit? Methane mainly comes from three sources - cows (a third), rice fields, leaky oil and gas plants and landfill farts (that’s a scientific term). Potential solutions range from different animal feeds (feeding cows seaweed can reduce their methane output by 80%) to draining rice paddies more frequently (it’s microbes in the water that release the methane). The biggest difference though, would be from limiting fossil fuels (short term, dealing with the leaks; long term, banishing them to the history books).
Most of it comes from agriculture; nitrogen-based fertilisers are sprayed on cereal and veg crops, they get jiggy with microbes in the soil and create nitrous oxide. That floats into the air, where it stays for about 100 years. Once it’s up there, one of it’s favourite snacks is ozone layer.
It’s also released when permafrost melts. Recent studies in Alaska have shown that thawing permafrost could release 12 times more nitrous oxide than scientists previously thought.
But hydrogen has one big problem - it doesn’t like to be alone. It’s in nearly everything, but in nature it hardly ever hangs out solo - it’s always with other things (e.g. H20). To use it as fuel, we have to split it, and that process has a ferocious, hangover-level, appetite. To meet current hydrogen demand we’d need more electricity than the EU currently makes in a year…
Hydrogen could prove a real game changer where electrification is harder (e.g. running cargo ships and planes off batteries is tricky). Though to play any role, the tech and renewable energy infrastructure need to be there to help it scale.
The good guy; the green part means it's made with renewable electricity. But, it’s expensive (roughly twice the price of blue hydrogen), as it requires a whopping amount of energy - and renewables so far have not been able to quite meet demand.
Scientists had a sneaky feeling CFCs were bad in 1974, 11 years before the hole in the ozone was discovered over the Arctic. But the size of the hole freaked the world out - and suggested CFCs had a much stronger effect that scientists had thought.
In 1987, within just two years of its discovery, an international treaty cut their use in half; the 1990 Montreal Protocol then banned them - in developed economies from 2000, and developing from 2010. (HFCs and HCFCs, other naughty though-not-quite-as-naughty refrigerant gases, had later phase out dates). It was a proper whoop whoop moment for climate science and diplomacy.
But the fact they’re now rarely used doesn’t mean they’ve disappeared. All those forsaken fridges are out there somewhere, with their mini gas canisters full of CFCs sitting there like unexploded climate bombs. A single molecule of CFC 12, the most common, can hold nearly 11,000 times the heat of carbon dioxide. That is quite potent. Managing all those little canisters is vital; if they were to leak, the Drawdown study estimates it would have the equivalent effect of 17 years of US C02 emissions. Disposing of them is not a complicated process, but someone’s got to manage it.
It exists naturally, but Fritz Haber found a way to make it using nitrogen from the air and hydrogen. Then, in 1910, Carl Bosch (nephew of Herr ‘household appliance’’ Bosch) managed to make that process industrial. A voila, the famous Haber-Bosch process that is still used today. Many consider it one of the most significant developments of the 20th century.
That process, however, produces the same carbon footprint as Canada (1.8% of global emissions) and is the hungriest industrial process behind only steel and cement. 80% goes into fertiliser but it’s also used in plastics, refrigeration, textiles, explosives and pharmaceuticals (it’s your best buddy if you’ve been supper to a mosquito).
There is talk of ‘green ammonia’ - where the C02 generated when it’s made is trapped in rocks, or that renewable electricity is used. Some scientists are looking at its ability to be burnt as a shipping fuel; liquid petroleum gas (LPG) engines can be adapted to use it - but, whilst it doesn’t release C02 when burned, it does emit nitrous oxide (not ideal).
Some believe that is true globally - others believe that should only be the case in developing economies, that it is irresponsible for developed economies to invest in it. Australia, amongst others, has gone big on LNG. The Gorgon Project, one of the world’s largest LNG production sites, is the largest single resource project in Australian history. Over five years it would store the carbon produced (about 20 megatonnes) in rocks 2km underground - though an Australian Institute report believes that is a fraction of the 260 megatonnes of carbon released over the same period once all the gas is extracted, compressed and then burned. That’s not exactly carbon neutral. It also tends to leak methane as it travels.
Carbon neutral LNG is a growing trend. It doesn’t mean, however, that it is produced without carbon - it just means the carbon produced when it is made, moved (and sometimes combusted) is offset.