Chapter 1: Introduction to Human Impact

In contemporary times, human activities are transforming the planet at an unprecedented speed. Despite the looming threat of climate change, our fossil fuel emissions continue to rise. This has endangered nearly one million species and altered more than 70% of the planet’s ice-free land.

While the scale of current global change is unparalleled in history, it’s essential to recognize that ancient civilizations also left their mark on the environment. A recent study published in Science posits that humans have significantly influenced the landscapes they occupied for the past 3,000 years.

Many existing archaeological models underestimate the extent of land utilized by ancient populations for hunting, farming, and grazing. As noted by Erle Ellis, an environmental scientist at the University of Maryland and one of the study's authors, these models often rely on assumptions and limited data.

While there is no shortage of information regarding ancient human activities, it has largely remained scattered across various archaeological studies worldwide. To tackle this, Ellis and his team engaged 255 archaeologists to provide insights on land use from 10,000 years ago to 1850, covering 146 regions across all continents except Antarctica.

The significance of this collaborative effort has not gone unnoticed. Robert Kelly, an archaeologist at the University of Wyoming, stated, “I believe that large global patterns across space and time are the primary contribution that archaeology makes to the study of humanity.” John Williams, a paleoecologist from the University of Wisconsin, called the study an important advancement, noting that archaeology is gradually embracing big data methodologies.

The first video, "A 300,000-Year History of Human Evolution," explores the extensive timeline of human evolution, providing context for understanding our long-standing impact on the planet.

Chapter 2: The Early Use of Land

The consolidation of this data revealed that as early as 3,000 years ago, human activities such as farming, herding, and hunting-gathering began to significantly reshape the Earth. Notably, 10,000 years ago, hunting and foraging practices were prevalent in 82% of the surveyed areas. As Ellis pointed out, “Hunter-gatherers were utilizing land essentially everywhere, covering vast territories.”

This groundbreaking map detailing the global reach of foraging may be the first of its kind, according to Lucas Stephens, an archaeologist at the University of Pennsylvania and lead author of the assessment. “There isn’t a model for foraging,” Stephens remarked, highlighting a crucial gap in our understanding of land use. Importantly, the foraging lifestyle, encompassing a variety of activities, can drastically affect the environment. Many societies based on foraging used fire to clear forests for hunting, further altering the landscape.

Around 6,000 years ago, the rise of agriculture and pastoralism began to spread globally, leading to a decline in foraging practices. At this juncture, 42% of the regions studied reported agricultural activities. Furthermore, the research uncovered that intensive agriculture emerged much earlier than previously estimated—over 1,000 years ahead of predictions made by the History Database of the Global Environment (HYDE). Ellis noted, “We observe that intensive agriculture began hundreds to thousands of years earlier than many models suggest.”

The second video, "Why Is There Only One Species of Human?" delves into the evolution of humanity and the implications for our environmental impact.

Chapter 3: Implications for Modern Conservation

These findings can refine models used for predicting climate change, according to Ellis. What he finds particularly compelling is how this research illustrates the enduring relationship between humans and the environment, a concept that is crucial for conservation efforts. In certain areas, plants and animals may have evolved alongside human land use. “Therefore, when considering conservation, we must integrate the knowledge of local communities,” Ellis emphasized.

The results may also intensify the ongoing debate among archaeologists and geologists regarding the Anthropocene—a proposed geological epoch characterized by human influence. Although it represents a mere millimeter of Earth’s extensive history, some scientists argue that the profound alterations we are making to the planet warrant formal geological recognition. A panel, known as the Anthropocene Working Group, recently voted to define this era as beginning in the mid-20th century, a period marked by rapid population growth and increased fossil fuel usage.

However, Ellis, a member of this group, disagrees with that timeframe. “While there is no doubt that human transformation of Earth accelerated significantly around that period, it is crucial to recognize that it took millennia for this dramatic change to develop,” he stated. “Understanding the depth of our impact on Earth requires an appreciation of the long-term acceleration of human influence.”