I have invested for years in the ETF ICLN. It has been going sideways; I consider it a long-term play. I only hope that Earth will have a long term.
I've recently added QCLN to my portfolio. This is speculative. I expect it to remain in the toilet until the current US Executive Branch is replaced, then I expect it to climb. If Democrats gain the Senate as well, I expect QCLN to soar.
I may continue the "CLN" theme with the new ETF ECLN.
The money I have invested in these ETFs is all money I can afford to lose.