This is classic dog wags the tail and vice-versa. Is it the demand causing these corporations to make the product or are they creating the demand through plentiful supply and marketing?

If these entities were to make something with lower emissions and marketed that as a better alternative will nobody buy that something? I highly doubt it...

I'm glad someone else understands this. Everytime I see the statistic about corporate emissions, I can't help but think about how it's so misleading. Exxon et al keep polluting because we keep collectively buying their product.

That doesn't absolve them from their efforts to discredit climate change research, but to suggest they are just some evil entity polluting at will is just ridiculous.

I agree with this entirely. Of course there are corporations responsible for way more than myself. But using it as a means to justify myself doing nothing to reduce my own consumption is just backwards and stupid. It's comparing a bad thing to another really bad thing but they're both still bad things. Should they stop doing what they're doing to contribute to this, yes. Should I also? Also yes lol. Plus like your comment said. These companies are driven by our own demand. It's our fault for supporting and relying on the way things are for sure.

TL;DR:

Consumer choices can influence industries, but it is impractical to solely rely on this to drive ecological change due to factors such as lack of awareness, inconvenience, habits, price and limited to no alternatives. Government subsidies for ecologically detrimental industries and the lack of subsidies for ecologically beneficial industries worsen the effect. Improved legislation is necessary to address these issues by enforcing ecologically beneficial industry practises and guide consumers.

Verbose:

I agree with you partly. Yes, consumer choices do affect which companies get money and which don't. But I would say that consumers are not completely responsible for the practises of a company. If a company chooses to power their production based on fossil energy carriers there's not much a consumer can do about it. Sure, they can stop buying from them. But for that a lot of things must happen. First of all they must know about it. And if it's not printed fat on the packaging or news are screaming about it, there is a high probability that they will never know about it. They could ask the companies themselves. And even if companies would be transparent and honest about their response, there's only a small fraction of people who would do this. That's because it's inconvenient. As ugly as it sounds, people hate inconveniences. A lot of people don't want to spend their precious free time with writing or calling the hundreds of companies, whose products they use, to ask about their production practises. Finally, if consumers eventually learn about the ecological impact of their products, they still need to collect a significant amount of mental energy in order to make the conscious decision of not buying them and possibly looking out for alternatives. That's difficult, because people easily get used to stuff and it's psychologically hard to change habits. And they'd need to do this for every single product they use. Even worse, in a critical amount of cases there aren't even alternatives available to consumers. If you continue buying the wrong products (in an eco sense), because you don't have access to an (affordable) alternative, that will send the wrong signals. The market won't see an increased demand for ecologically friendly products in these (significant amount of) cases, but quite the contrary. I don't say that it's impossible, clearly humans seem to have the capacity of intelligence and can be educated to do better, but I claim it's impractical for the everyday life of the masses. Especially, we don't have the time to wait until the majority of people is able to change their consumption behaviour. That's why we need laws, such that law makers do the hard work of paving the way for ecologically beneficial industry practises, so the Jon or Jane Doe going to the grocery store after a long day of work doesn't have to worry about which products to buy.

Besides, in a lot of countries fossil based energy carriers are still cheaper than environmemtally friendy alternatives, sadly. If companies start to completely switch to green energy, this would increase the price. Increasing the price can lead to less consumers buying the products. Either because they can't afford it or because they want or need to save money. This again would turn the circle of environmental destruction once more, since the cheaper alternatives, which consumers are looking out for, are usually less beneficial or even detrimental to the environment.

Also let's not forget that also a lot of countries subsidise industries which are major contributors to greenhouse gases, e.g., the meat industry. Meanwhile there is a lack of sufficient subsidies for ecologically better industry segments. I live in a world where an organically grown cucumber is much more expensive than a pack of meat. That can't be right.

We need good laws and can't rely on the behaviour of consumers alone. There's no way around it.

People demand goods and services. They very often do not care how those get to them. If they did, most corporations would go out of existence for using child and slave labor.

Your average person is not the one fighting against climate change regulation. It is the corporations throwing billions at government officials to not regulate them.