By one accounting, 90 companies. Richard Heede …

…(pronounced “Heedie”) has compiled a massive database quantifying who has been responsible for taking carbon out of the ground and putting it into the atmosphere. Working alone, with uncertain funding, he spent years piecing together the annual production of every major fossil fuel company since the Industrial Revolution and converting it to carbon emissions.

[source]

See the graphic at the top of the post. There is an interactive version HERE, with much more detail.

Heede is one of the victim’s of Lamar Smith’s McCarthy-esque attack on climate scientists. (Smith is currently being opposed in his run for Congress by Tom Wakely, who is running in large part on a climate change ticket. I suggest you donate an amount of money that has the numerals “350” to Wakely. I did.)