Yeah, FreeCAD is great, but I can only think of one project that I’ve done where SolveSpace absolutely could not work for the geometry I needed and I had to rebuild it in FreeCAD. But that’s just a product of what I am building: simple things like brackets, knobs, and replacement lids mostly. I don’t need chamfers, drafts, lofts, etc. and I get what I need with minimum of time and effort using SolveSpace.

When I do need those features, complex geometries, or modification of pre-built step files, FreeCAD has never failed me.

No one mentioned SolveSpace, so… SolveSpace. Solvespace is a fully functional 3D parametric CAD solver in a free, cross-platform, open-source, portable, single self-contained executable 10 MB file.

I do a fair amount of hobby 3d printing and SolveSpace makes design and CAD stupid easy. The interface is perfectly laid out, the hotkeys are intuitive, and the capabilities make small-scale projects a breeze.

Now, the program has its limitations, but if I just want something quick and simple, there is nothing better.

Mineralization. There is a paper from Nature estimating a capacity of 10,000 - 100,000 Gt CO₂ for mineralizing CO₂. This is more than sufficient for the 1,000 - 2,000 Gt CO₂ that we will need to remove from the atmosphere once we reach zero emission. Needless to say, mineralization to a solid carbonate would remove the threat of fugitive emissions permanently.

People can complain about DAC as expensive etc., but it is the fastest way to bring down CO₂ once emissions have ceased. Without it, we will be stuck with the climate effects of increased greenhouse gas emissions - severe storms, erratic climate events - for hundreds of years. The fact that it is expensive just means that we will need to know what our target CO₂ level is and how how fast we want to get there.

Often, it’s said, “Just plant trees.” However, trees are not a sufficient solution for greenhouse gas reduction. A 2022 article in Environmental Research Letters predicts a “121 Gt C increase in carbon in forests over the course of this century.” That’s great, but it’s not enough to get GHG down to an ideal level. Of course, that doesn’t mean that we shouldn’t engage in sustainable agriculture and reforestation - we should, but we should not rely on it as a climate restoration strategy because it cannot deliver those kinds of GHG reductions.

That was what happened to our data on the “family computer”. My parents were not happy with me that day.

First, find a rock.

You make a good point. If there were no potential solution, trees (i.e. sustainable agriculture) would be the best solution. It would take a few hundred years but we would get back to pre-industrial levels at zero emissions.

The potential solution is direct air capture. Although there are many forms, I am fond of the method proposed by Klaus Lackner. By making a large number of CO₂ scrubbers, as opposed to a few very large ones (like Climeworks), the economics of carbon removal get very easy, very fast.

A 1 m² area that gets an average 2 m/s breeze through it sees about a gram of CO₂ pass through every second. This is about 100 kg of CO₂ per day. So let’s make a machine that catches CO₂ from a 2 × 5 m area and catch 1 t per day, or 300 t per year. For this machine to pay off its carbon debt, it’s going to need to be around for a while, say 10 years. What happened during those 10 years? 3 kt went out of the atmosphere for good. If you liquefied the CO₂, this would fill 3 McMansions.

Lackner seems to think we can build this machine for $100k. Now we have a price of $30/t of CO₂ captured. As it stands, we need to get about 1,000 Gt of CO₂ out of the atmosphere to stabilize the climate, so we need to build $30T worth of these machines. How could we possibly afford that? Well, we would spend ~$1T on this per year for about 30 years.

Where would that kind of money come from? Sacrifices would be needed, it’s true. I think the biggest would be giving up on war. Global defense budgets add up to this scale of funding, and if the nations of the world decided to put an end to war, we could use the peace dividend to pay for the restoration of the climate. Perhaps there wouldn’t be any other sacrifices needed at all.

If this seems unrealistic to you, that’s ok too. We can still keep war and do things the slow way or (more likely) not do them at all. I suppose a decade-long nuclear winter would also do wonders for global cooling and emission reductions. Personally, though, I would prefer world peace and direct air capture to stabilize the climate.

I think, from your post, you would agree. If we are going to fight, we should fight climate change, not each other, no?

Of course, trees should be planted, but the notion that they are an expedient way of decarbonizing the atmosphere is plainly wrong. Had nature optimized plant life to remove carbon from the atmosphere, there would be no CO2, no plants, and the planet would be a snowball instead of the vibrant, warm (too warm) climate we have today. Nature maintains stasis - and therefore life - by avoiding carbon sequestration.

You may have seen the Keeling Curve, the “graph of the accumulation of carbon dioxide in the Earth’s atmosphere based on continuous measurements taken at the Mauna Loa Observatory on the island of Hawaii from 1958 to the present day.” Notice that it goes up and then down in Seasonal Variation. This is because, during the summer months in the Northern hemisphere, all the plant life decarbonized the air to form new leaves and greenery. Then, in the winter, all the leaves fell back to the ground where they were consumed by fungi and detrivores and converted back to CO2.

Suppose we stopped producing fossil fuels tomorrow. The Keeling Curve would still have seasonal variation, but it would be against a constant mean, rather than the current rising one. If we then just planted more trees, the seasonal variation would increase, perhaps, but the mean would remain more or less constant. While beneficial, none of the planting would make more than a dent in the hundreds of billions of tons of anthropogenic CO2 in the atmosphere. The potential for soil sequestration is on the order of 1 Gt/year.[source] That doesn’t mean we shouldn’t practice sustainable agriculture and forestry, rather we should, but it won’t reduce our carbon debt or start to reverse climate change. Believing that it will is just magical thinking, coincidentally an inadvertent implication of the meme.

Given that nature is (almost) perfectly inefficient at long-term carbon sequestration, it would seem that effective, long-term decarbonization of the atmosphere on any scale short of millennia has to include mechanical means, no matter how inefficient such means may appear.

Hey, what are the exact dimensions of the part with the thermal paste? I’d be curious know just how much area is being covered.

Because crystallography and solid state chemistry is the foundation of every modern convenience?

But it’s also beautiful. If they’ve never heard of Bravais-Friedel-Donnay-Harker, then you can’t really blame them for not knowing.

HCP FTW.

What would be the plan to control costs? Fe2O3 nano particles aren’t cheap, as you can see. At $3M per tonne and the need for, say, 10 gigatonnes to start off… That would put the cost of this plan at $30 quadrillion. I’m sure that, at that scale, the price would come down, but that’s a pretty high starting point. Toss in the fact that these nanoparticles would naturally settle out over time and the costs would increase further.

No one said terraforming was going to be cheap, but at that price, there has to be a less expensive option.

Yeah, if that’s what Johnny Cash was talking about, then what was Trent Reznor talking about?