that much of it

sentece: if it were that bad people would not be doing that much of it.
what i don't understand is the expresion 'that much of it'
what's the meaning of it in that sentence?
Thanks.

What was the preceding sentence?

it is an old article talking about the defence of recycling.
the previous sentence is:
.. So it is a little naive to say that recycling is bad when frankly if it were ...

"people would not be doing that much of it".
In this case 'that' is an adverb and is used in pretty much the same way as 'so'.
"I really hated that film." -
"Oh come on. It wasn't that bad."