Human beings have always looked for better, more efficient tools to improve their lives and master their environments. When historians discuss "the" Industrial Revolution, though, they are primarily referring to a period of time in the 18th and 19th century in Europe, when traditionally agrarian and rural communities moved into the cities and industrialized.
One of the earliest phases of the Industrial Revolution, often dubbed the Agricultural Revolution, marked a massive shift in how Europeans were able to control their environments through agriculture. Prior to the 1750s, most farmers only harvested enough food to survive; they rarely, if ever, had a surplus.
This meant that the environment controlled the lives of the farmers--if there was a long winter, flooding, or an infestation of bugs, for example , the farmers would be left with nothing. In the 1750s, though, the price of grain skyrocketed, leading many newly-wealthy landowners to invest in innovation. Many of the discoveries of this period exemplified the way humans were learning to control the natural world.
The Norfolk system of crop rotation, for example, ensured more could be harvested on less area, using all the land, all the time—no field ever went fallow. Additionally, while animal husbandry (or selective breeding) had been practiced since humans began domesticating animals, new methods allowed for the breeding of new farm animals: for example, the traditional Lincoln Longwool sheep was bred into the Dishley Leicester sheep, which had denser fleece and more meat on its bones.
It's also important to acknowledge the new ways that humans were taking advantage of their environments during this period. England's rocky bluffs, for example, were full of natural minerals, coal, and iron. As an island, with major river passages throughout, the English were able to transport these good quickly and cheaply. Humans were beginning to figure out how to use their environments as tools of industrialization.
Urbanization, which was also an effect of industrialization, also changed humans' relationship to their environment. Before the Industrial Revolution, European life centered on the farm and the home. Over the course of about a century, European life turned almost inside out, with massive urbanization and factory work overpowering agricultural and artisan trades.
Although middle class Europeans were getting healthier during this period, thanks to more abundant food and new discoveries in health and medicine, poor industrial workers in the overcrowded cities were suffering from poor sanitation and dangerous working conditions. Between 1800 and 1850, for example, the population of London nearly doubled. Simultaneously, the physical size of London remained the same, and to some extent became even smaller as a huge amount of housing was demolished for commercial spaces and factories. This led to severe overcrowding, poor health, and an ever-present fog of smoke from factory chimneys.
In other words, as middle class industrialists began to transform their environments into tools for industrialization, the poor laborers in rapidly urbanizing cities were being overwhelmed and threatened by their environments. It would take another century and significant work for these environments to become livable again.