I don’t know how it goes in the US, but in Finland the concept of lex praevia is set in the Finnish constitution.

Section 8 Principle of legality in criminal law No one shall be held guilty of a criminal offence or be sentenced to a punishment on account of an act that did not constitute a criminal offence under law at the time when it was committed. The punishment imposed for an offence shall not be more severe than that provided by law at the time of commission of the offence.

While the Finnish constitution is not set in stone, and can indeed be amended via a supermajority, there’s practically no government that would actually allow that kind of change to legislation. It’s obvious to anyone what breaking said principle would mean and strive for, and doing so would require at least four different parties to agree.

Well, they can create a law to properly fine such things in the future. If current law doesn’t allow imposing a proper fine, it’s not possible to amend in a way that allows fining after that.

At least in Finland you can only get punished according to the law that was in place when you did the act. Not any laws that were passed later. AFAIK the same is true in the US as well.

Well, Finnish forests are heavily forested and the cut down area was likely farmed/planted as well. They wouldn’t have managed to purchase the land for this purpose if there were actual old growth trees there, only few such places remain.

The environment around the forest matters more, e.g. rivers, ditches, swamps and so on. Most forests here are cut every 40-90 years and replanted after cutting.

The main issue here has less to do with the forest being felled, and more to do with the incorrect management of things like wastewater and possible endangered habitats. These things are mostly an issue in areas that are zoned. Outside the zoned areas most of Finnish forest is actively managed for forestry and is cut clear and replanted periodically over 40-90 years depending on latitude and type of forest.

Google would’ve gotten the rights to cut if they just bothered to wait a bit and fill in the required paperwork. In most of Finland you just tell the government you’re going to cut down a forest and get working. Instead they chose to expedite the process and are now being criticized for that purpose.

Typically forests aren’t clear-cut to that extent at a single time, and the top soil remains in place. The scale has a danger of rain washing off the soil and adding nutrients to the nearby river and thus the baltic sea as well. Those should’ve been properly managed and planning that management was the part they skipped. The forest would’ve become timber and other products in due time anyway (which it now won’t since it’s not legally cut).