Very close - I can tell you are pretty advanced.
There are 2 that are not correct.
1. -"A wreath was to be laid in remembrance of the glacier" --> Can I write: a wreath was set in remembrance...?
Notice that the first sentence is talking about the future (to be). So, you must do the same in yours. "A wreath was "to be" set in remembrance...
2. -"An initiative calling for carbon dioxide emissions in Switzerland to be reduced to zero by 2050 --> Can I say: an initiative looking for reducing... to zero by 2050"??
No, but you could say either of these:
a. an initiative looking for reduction...
b. an initiative looking to reduce...
I hope this helps,