I saw on one of the space blogs (that I'm too lazy to find) that they brought massive bags of super-strong concrete (refractory cement?) for the pad after the last damage, and those bags disappeared so it was assumed the new cement had been used, but they were later spotted elsewhere at the facility, so there was some conjecture that they may have used standard cement again and doing this knowing it is a sacrificial pad. So don't be too surprised, or too concerned if the pad is damaged - the fancy cement is on site.

It's already solved, technically speaking. There are several companies already producing green steel, which only make about 5% of the greenhouse gases in production. So the question comes down to cost, not feasibility. Currently green steel costs about 20-30% more than traditional steel. Given these are really just pilot plants and the cost isn't orders of magnitude more expensive, it's not unreasonable to expect green steel to become price-competitive in a few decades. Some (few) companies will wear the extra cost for PR reasons, but it's a hard sell right now. Edit: There may be carbon offsetting options available in some cases to account for the extra cost, so these green steel companies may already be somewhat cost-competitive.

We have some observations that show galaxies with and a few without companion dark matter. It has momentum and interacts with gravity. The Bullet Cluster is considered to provide direct evidence of dark matter, and none of the MOND theories to date can explain these types of observations.

Edit: I think a lot of people mix up dark energy and dark matter in this regard. Dark energy amounts to a fudge factor to make the maths work, but we know a lot more about dark matter. It really does appear to exist, but because it doesn't interact with the electromagnetic field we can't see it directly.

Another case where a line chart would be far more informative. Using novel charting methods purely for their novelty, when traditional forms are superior is not beautiful.