It brings to mind images from the Lord of the Rings, where the Ents, fed up with the evil mage Saruman's reckless destruction of nature, attacked his fortress at Isengard. (Click here to read up on the Saruman saga at Wikipedia.) The Ents, led by Treebeard, hurled boulders at Saruman's army and even unleashed a river by smashing a dam, drowning orcs in a torrent of water that only the trees could withstand due to their mass and height.
It was a brilliant display of evil being defeated by the forces of nature. All the weapons used by the Ents were elementals, too: the boulders were from rock, the flood was composed of water, and the trees themselves were made of wood. The symbolism in this work is very powerful, and the message remains valid even in modern times: That nature is more powerful than evil men.
Why famines? Because radical weather patterns caused by global warming will disrupt food production, causing droughts in some areas and floods in others. As food production plummets, famine will become widespread. We are, after all, in a "food bubble" right now.
Why infectious disease? Because only balanced, healthy ecosystems keep infectious disease at bay. When ecosystems are disrupted, they become breeding grounds for infectious pathogens. Those pathogens spread quickly through non-natural animal production facilities (bird farms, cattle ranches, fish farming ponds, etc.), accelerating the mutation rate and greatly increasing the chance of cross-species infections that can then be spread by human-to-human contact. Bird flu, for example, remains globally uncontrolled and could mutate into a human form at any moment.
On top of this, our hospitals are actually breeding antibiotic-resistant superbugs through the rampant abuse of antibiotics, and our food supply has very little safety oversight (as we've seen with deadly bacterial contaminations of peanut butter, spinach, onions and other food items over the past two years). There's also mad cow disease, which can easily pass to humans through beef products, and which cannot be killed by cooking the meat. And don't forget our modern corporate-controlled agricultural practices which eliminate biodiversity and base the future of humanity on a few patented strains of food-producing crops that are practically begging to be wiped out by blight or some other crop disease.
Of course, nature is not vengeful, and she does not act out of cruelty or anger. Rather, nature responds in kind to the treatment it has received. When humans treat nature with respect, she responds with abundant crops, predictable weather and stable ecosystems that sustain life. But when humans treat planet Earth as a dumping ground for chemicals, pharmaceuticals, power plant emissions and automobile exhaust, nature responds in a way that ultimately "rebalances" the global ecosystem.
And how do you rebalance the global ecosystem? The most direct way, from nature's point of view, is to get rid of the cancer that's destroying the planet. That cancer, of course, is us. Humans are, by far, the most destructive force on the planet and the greatest threat to life and biodiversity on planet Earth. It's almost like finding two fish in a fishbowl who have hatched plans to crack the bowl and drain the water out because it would make room for more fish. Silly fish, huh?
It is clear that humankind, as situated today, is incompatible with sustainable living, and unless humans can somehow find a way to radically reduce their "footprint" on planet Earth, the natural consequences will be quite severe.
Of course, it's only severe from the point of view of humans. From planet Earth's point of view, humankind can simply be shrugged off in the blink of an eye (say, 10,000 years), and the planet will go on living without the destructive presence of modern humans.
Let's face it: Humans are infants, and we act like children in the way we deal with our home planet. Perhaps a future civilization will do better than this one, because the one we live in right now is headed for certain disaster. Remember: modern human civilization is not the first civilization to rise and fall on this planet, nor will it be the last. All we can hope for is that future beings who inhabit this world will be wiser than we have been and will somehow find the presence of mind to stop destroying their planet before it destroys them.
In the mean time, you can do your best to honor and protect the planet by living a green lifestyle and remembering where you came from -- the Earth. We're all made of this Earth, and it is Earth water that fills that soggy mass of neurons in your skull. It is Earth iron that turns your blood red, and Earth air that fills your lungs with each breath. To honor the Earth is to honor yourself, for you are not separate from this planet, and your own health is inevitably tied to the health of the world you inhabit.