"...Exxon is treading dangerous waters by exposing itself to the same type of risks the rest of its portfolio is vulnerable to. A large portion, if not all, of Exxon’s portfolio is exposed to the potential shifts in industry and politics regarding climate risk."
First off, this follows the same old "let's pick on ExxonMobil because they are so big and no one likes them and they are an easy target" habit that I've previously discussed. Absolutely they are big, but they are only one part of the whole plastics industry. Anything said in the article against ExxonMobil can be said just as well against any other company making plastics from petroleum-based feedstocks. But secondly, the author is completely oblivious to that fact that the same equipment that ExxonMobil is investing in can be used to make the exact same plastics [*] from biobased feedstocks. Ethylene can come from petroleum crackers and it can come from ethanol dehydration facilities and the reactors can't tell the different. In both cases, the polyethylene plastic that is produced is the same. This means that investments in polyethylene production equipment, as well as equipment for polypropylene and any other other Big 6 polymers is an investment in the continued dominance of those plastics in the future. They are not merely investments in a petroleum-based economy.
The author goes on
"While it could possibly be an important source of revenue down the line, this transition into plastics leaves Exxon open to the emerging technology of bioplastics, a technology that is showing increasing promise..."Biobased plastics, both now and in the future will be one of two varieties: they will either be drop-in replacements for existing materials (such as the bio-based polyethylene I just mentioned) or they will be novel materials that don't currently exist and fulfil a niche need. Polylactic acid (PLA) is a good example of this. The former is much easier to achieve success in since the processing equipment, markets, engineering specs, regulatory approvals, etc. already are in place. The latter option is far more challenging to achieve success in since the materials are new and few people know they exist or understand (and trust) their performance and the new materials may not have the needed regulatory approvals.
I already mentioned the dominance of the Big 6 plastics. They, HDPE, LDPE, PP, PS, PVC and PET, account for 76% of the plastics market. That dominance resulted from the ability of these six materials to affordably meet the needs of a vast array of products. While it might be possible to chip away at some of the applications and replace them with new materials, that dominance will effectively remain in place for decades to come. The market share might drop to 75% or 70% or even 50%, but no one is seriously suggesting that these materials will not remain the Big 6.
I don't know whether ExxonMobil's investments are a good idea or not. My concerns however, are only about the ability of the markets to consume the additional output and not in the least about them using petroleum feedstocks. Looking forward 100 years from now, I would expect the world's energy supply to be from anything but petroleum, but I would still expect to find a world filled with polyethylene materials.
[*] "Exact"? Not quite. The biobased feedstocks will have some C14 that petroleum feedstocks won't, but you need some pretty good mass spec analysis to find that.