Context: Every major advance in agriculture has allowed global population to increase. Early farmers could settle down to a steady food supply. Irrigation, the ability to clear large swaths of land for farming efficiently, and the development of farm machines powered by fossil fuels allowed people to grow more food and transport it to where it was needed. What is Earths carrying capacity for humans? Are humans now exceeding Earths carrying capacity for our species? Many anthropologists say that the carrying capacity of humans on the planet without agriculture is about 10 million (Figure 1.1). This population was reached about 10,000 years ago. At the time, people lived together in small bands of hunters and gatherers. Typically men hunted and fished; women gathered nuts and vegetables. Obviously, human populations have blown past this hypothetical carrying capacity. By using our brains, our erect posture, and our hands, we have been able to manipulate our environment in ways that no other species has ever done. What have been the important developments that have allowed population to grow? About 10,000 years ago, we developed the ability to grow our own food. Farming increased the yield of food plants and allowed people to have food available year round. Animals were domesticated to provide meat. With agriculture, people could settle down, so that they no longer needed to carry all their possessions (Figure 1.2). They could develop better farming practices and store food for when it was difficult to grow. Agriculture allowed people to settle in towns and cities. More advanced farming practices allowed a single farmer to grow food for many more people. When advanced farming practices allowed farmers to grow more food than they needed for their families (Figure The next major stage in the growth of the human population was the Industrial Revolution, which started in the late 1700s (Figure 1.4). This major historical event marks when products were first mass-produced and when fossil fuels were first widely used for power. The Green Revolution has allowed the addition of billions of people to the population in the past few decades. The Green Revolution has improved agricultural productivity by: Improving crops by selecting for traits that promote productivity; recently, genetically engineered crops have been introduced. Increasing the use of artificial fertilizers and chemical pesticides. About 23 times more fertilizer and 50 times more pesticides are used around the world than were used just 50 years ago (Figure 1.5). Agricultural machinery: plowing, tilling, fertilizing, picking, and transporting are all done by machines. About 17% of the energy used each year in the United States is for agriculture. Increasing access to water. Many farming regions depend on groundwater, which is not a renewable resource. Some regions will eventually run out of this water source. Currently about 70% of the worlds fresh water is used for agriculture. Rows of a single crop and heavy ma- chinery are normal sights for modern day farms. The Green Revolution has increased the productivity of farms immensely. A century ago, a single farmer produced enough food for 2.5 people, but now a farmer can feed more than 130 people. The Green Revolution is credited for feeding 1 billion people that would not otherwise have been able to live. The flip side to this is that for the population to continue to grow, more advances in agriculture and an ever increasing supply of water will be needed. Weve increased the carrying capacity for humans by our genius: growing crops, trading for needed materials, and designing ways to exploit resources that are difficult to get at, such as groundwater. And most of these resources are limited. The question is, even though we have increased the carrying capacity of the planet, have we now exceeded it (Figure There is not yet an answer to that question, but there are many different opinions. In the eighteenth century, Thomas Malthus predicted that human population would continue to grow until we had exhausted our resources. At that point, humans would become victims of famine, disease, or war. This has not happened, at least not yet. Some scientists think that the carrying capacity of the planet is about 1 billion people, not the 7 billion people we have today 
 Question: this scientist in the eighteenth century predicted that human population would continue to grow until we had exhausted our resources.
Output: thomas malthus