This is one I've thought of for a long time. Plutonium 239, the stuff they use in civilian reactors, has a half-life of 24,000 years. That means that the most toxic substance known to mankind will only be half as toxic 24,000 years from now. That's more than three times the entire written history of humankind. How delusional do you have to be to think you can keep spent fuel rods safe for that length of time and who knows how many multiples of that for it to be "safe"?
http://swiftspeech.blogspot.com/2011/03/plutoniums-half-life-is-24000-years.html
Doug

We're so busy thinking about survival and prepping and issues like societal breakdowns, law and order problems, etc.
But how about what might happen when there's less money and resources to fight wildfires? Less money and resources to keep hydro-electric dams in repair, and the reservoirs behind them properly dredged. What happens with the environment we depend on: air, water, soil, biosphere, etc.?
Will we burn a lot more coal? Will we drill a lot more natural gas wells - without putting in groundwater safeguards? How long will those safeguards made of steel and concrete last? Right now there are hundreds of capped oil wells in the Gulf of Mexico. What happens when the steel rusts and concrete crumbles in the next 100 or 200 years?
And how about keeping nuclear power plants and infrastructure operating at peak safety and efficiency, then properly decommissioning them and storing and processing the radioactive wastes? A major plague or war - or just half a century of decline - might very well be what leads to meltdowns at various plants worldwide.
Just look at Chernobyl today. The Ukraine already has problems with the current containment system covering the ruins of the plant, so an international consortium has already pledged $1.8 billion to build a steel containment shell to be assembled away from the ruins of the plant, then will slid into position over it. The shell is expected to last about 100 years. And then what?
Ukraine Raises $785m To Seal Chernobyl Under New 'Shell'
"World governments pledge millions for the construction of a 20,000-tonne steel arch to prevent further radiation leaks."
http://www.guardian.co.uk/environment/2011/apr/19/ukraine-funding-cherno...
Chernobyl and Fukushima are great examples. Vast swath of land for miles around is now uninhabitable. Now this may be extreme, but iImagine if the world had half a dozen or more meltdowns like them more - like in India or South Africa - in the next 50 years.
I would love to hear your insights - especially if you have news articles or links to research - as to other problems may affect the environment.
Impetus
I was thinking of this as I read an article on gypsy moths...
How A Clever Virus Kills A Very Hungry Caterpillar
"The caterpillar is the gypsy moth in its larval stage, and the invasive species damages roughly a million acres of forest in the U.S. each year by devouring tree leaves. But the damage would be greater if it weren't for something called a baculovirus that can infect these caterpillars and cause them to engage in reckless, even suicidal behavior, scientists say. The virus is so effective that the government actually sprays it on trees to help control gypsy moth outbreaks."
http://www.npr.org/2011/09/12/140226986/how-a-clever-virus-kills-a-very-...
What if they weren't kept in check? And thank goodness the Rocky Mountain Locust has apparently been extinct for the past 100 years.
http://en.wikipedia.org/wiki/Rocky_Mountain_locust
Poet