Could you be more specific?

Global warming, Chernobyl, Fukushima, Some of the Superfund sites in the USA (https://www.epa.gov/superfund). In general, pollution of air, water, soil (http://www.vancouversun.com/Business/asia-pacific/Chuck+Chiang+China+replanting+forests+fight/9651435/story.html). Ozone, and the suspected role of CFCs. Shrinking ice packs and the effect on polar bears (http://www.adn.com/science/article/shrinking-faster-moving-ice-has-polar-bears-treadmill-stay-alaska/2016/02/06/).

That said, proving that man is entirely responsible for global warming and thereby shrinking ice and rising oceans is difficult. Showing that man's activities can contribute to or enhance a natural phenomena is fairly easy.

Feral pigs in Hawaii. Mongoose in Hawaii. Opuntia in Australia. Less clear are invasions of some organisms like the cactus moth. Is it moving entirely of it's own power, or is man inadvertently helping in some way? At any rate, the moth threatens Opuntia cactus in North America http://entomology.ifas.ufl.edu/creatures/bfly/cactus_moth.htm.

Other examples might include passenger pigeons, dodo birds, and other animals that may have been hunted to extinction for food or sport.

The list can be much longer depending on how strong you need the causal link and how global the threat must be. It would also change if the disaster was caused deliberately or inadvertently. So no one tries to move the Asian Citrus Psyllid around in the United States. Yet, its movement is facilitated by the transport of citrus fruits, trees, and related ornamentals. Hence quarantine measures are in place. This is in contrast to something like the Multicolored Asian Ladybug that was deliberately imported into the United States (http://www.ars.usda.gov/is/br/lbeetle/). It is considered a pest by homeowners, and being a generalist predator it may be forcing other ladybug species to extinction (https://www.ethz.ch/content/dam/ethz/special-interest/usys/ias/grassland-sciences-dam/documents/Education/Global%20Change%20Biology/Executive_Summary_Lea_Stauber.pdf).

Did this answer the question?

Dear Timothy,

I'm sorry if my question was not clear. But your answer is quite suitable. Thank you very much for this rich comment.

With my best regards

Prof. Bachir ACHOUR

Dear Sir,

Please have a look at this link.

http://www.mensxp.com/special-features/today/9034-7-worst-man-made-ecological-disasters.html

Good luck

I would add the decline of pollinators, since this is global and may have serious long-term consequences.

You could include examples from fisheries, like salmon along the Pacific coast of NA. I am not a fisheries expert, but I suspect that globally there are many other examples.

Zebra mussel in the Great Lakes of NA (http://www.great-lakes.net/envt/flora-fauna/invasive/zebra.html). Jumping carp in the Illinois river (http://illinoistimes.com/article-7433-attack-of-the-flying-fish.html).

Desertification (maybe) http://archive.unu.edu/unupress/lecture12.html. As the article points out, it is difficult to separate short term changes from long term changes, and it is hard to separate natural changes from man made changes. Is man a cause, or simply responding to an effect?

The "Dead zone" in the Gulf (http://www.nature.org/ourinitiatives/regions/northamerica/areas/gulfofmexico/explore/gulf-of-mexico-dead-zone.xml). In general algal blooms caused by fertilizer run-off from agriculture or urban lawns that cause fish deaths in lakes, rivers, and oceans.

Large fires caused by land management strategies that prohibit burning in areas that were accustomed to periodic natural burns. The whole field of fire ecology is focused on this issue. The problem is that some species need the burn for seed germination, while the large build-up of fuel produces fires that are hotter and end up killing individuals that would otherwise have survived.

Possibly the great Pacific garbage patch: http://oceanservice.noaa.gov/podcast/june14/mw126-garbagepatch.html.

Dear Timothy,

Thank you very much for all these examples. They are really eloquent.

With my best regards

Prof. Bachir ACHOUR