Al Gore is irrelevant to me, I'm not an American. We have known, that CO2 emissions is going to lead to climate change for 100 years (although initially it was not yet clear, that this is dangerous)
Yes, shifting economy to renewable energy is not enough, transportation is also a huge problem as is agriculture , especially because of ruminants and deforestation.
And right, we had decades to address all these problems, but governments did not care, and they still address only parts of the issues.