An interesting article from the Foundation for Economic Education reminds us that crises are often solved by the development of new technology. As an example, they offer the Great Horse Manure Crisis of 1894.
Nineteenth-century cities depended on thousands of horses for their daily functioning. All transport, whether of goods or people, was drawn by horses. London in 1900 had 11,000 cabs, all horse-powered. There were also several thousand buses, each of which required 12 horses per day, a total of more than 50,000 horses. In addition, there were countless carts, drays, and wains, all working constantly to deliver the goods needed by the rapidly growing population of what was then the largest city in the world. Similar figures could be produced for any great city of the time.
The problem of course was that all these horses produced huge amounts of manure. A horse will on average produce between 15 and 35 pounds of manure per day. Consequently, the streets of nineteenth-century cities were covered by horse manure. This in turn attracted huge numbers of flies, and the dried and ground-up manure was blown everywhere. In New York in 1900, the population of 100,000 horses produced 2.5 million pounds of horse manure per day, which all had to be swept up and disposed of.
In 1898 the first international urban-planning conference convened in New York. It was abandoned after three days, instead of the scheduled ten, because none of the delegates could see any solution to the growing crisis posed by urban horses and their output.
The problem did indeed seem intractable. The larger and richer that cities became, the more horses they needed to function. The more horses, the more manure. Writing in the Times of London in 1894, one writer estimated that in 50 years every street in London would be buried under nine feet of manure. Moreover, all these horses had to be stabled, which used up ever-larger areas of increasingly valuable land. And as the number of horses grew, ever-more land had to be devoted to producing hay to feed them (rather than producing food for people), and this had to be brought into cities and distributed—by horse-drawn vehicles. It seemed that urban civilization was doomed.
Of course, urban civilization was not buried in manure. The great crisis vanished when millions of horses were replaced by motor vehicles.
There's more at the link. Interesting and worthwhile reading.