Think of it as old Mother Nature with a bad case of diarrhea. It is just semi-digested vegetable matter released from deep within the bowels of the earth. For those unfamiliar with organic chemistry or the geology of petroleum I would point out that in some places in the natural world there are all kinds of poisonous gases hissing forth from fissures directly to the atmosphere and sometimes even catching fire. Crude oil and bitumen burble forth naturally from the ground in many places. The release of these substances is often just the result of earth movement. In this particular case however the release was triggered by a man-made probe. Philosophers say “moderation in all things”; and this applies to chemistry as well. Things vital to life, basics such as salt, oxygen, and even water are deadly toxins in excess. An excessively high concentration of any chemical element spells death to any living creature. To the animal kingdom it is not even an extinction. It is, however, the end of life for some individuals of a given species. The impact on people is more economic than physical.
It is not the end of the world; just the end of the world as they know it.