Here's an example of how carbon pricing is totally useless in a small country like Canada.
The provincial auditor general reported in 2016 that Ontario's expert expected the Wynne government's cap and trade scheme to reduce man-made emissions by 3.8 megatonnes by 2020:
http://www.auditor.on.ca/en/content/news/16_newsreleases/2016news_3.02.pdf
In 2018, the world produced 37,000 megatones of emissions:
https://www.cbc.ca/news/technology/carbon-pollution-increase-1.4934096
Thus, if the cap and trade scheme had actually met its projected target, Ontario would have reduced global emissions by 0.0001% by next year. Rounded off, that's a decrease of 0%.
You can extrapolate the numbers for the entire country and you still would get a reduction of 0%. Totally meaningless.