From UPSC perspective, the following things are important :
Prelims level : Geological time scale
Mains level : Debate over the epoch
- A committee of geologists has now proposed to mark the start of the Anthropocene in the mid-20th century, based on a striking indicator: the widely scattered radioactive dust from nuclear bomb tests in the early 1950s.
A new human age
- Human impacts are everywhere. Our societies have changed Earth so much that it’s impossible to reverse many of these effects.
- Examples of how human societies are changing the planet abound — from building roads and houses, clearing forests for agriculture , to shrinking the ozone layer, driving species extinct, changing the climate and acidifying the oceans.etc.
- Some researchers believe these changes are so big that they mark the beginning of a new “human age” of Earth history, the Anthropocene epoch.
When to mark as beginning?
- Researchers debate the utility of picking a single time line in Earth’s geological record to mark the start of human impacts in the geological record.
- Maybe the Anthropocene began at different times in different parts of the world.
- For example, the first instances of agriculture emerged at different places at different times, and resulted in huge impacts on the environment, through land clearing, habitat losses, extinctions, erosion etc.
- There are multiple beginnings, scientists need to answer more complicated questions — like when did agriculture begin to transform landscapes in different parts of the world?
- This is a tough question because archaeologists tend to focus their research on a limited number of sites and regions and to prioritize locations where agriculture is believed to have appeared earliest.
- To date, it has proved nearly impossible for archaeologists to put together a global picture of land use changes throughout time.
Global answers from local experts
- To tackle these questions, collaboration was held among archaeologists, anthropologists and geographers to survey archaeological knowledge on land use across the planet.
- They mapped the current state of archaeological knowledge on land use across the planet, including parts of the world that have rarely been considered in previous studies.
With onset of agriculture
- Archaeologists reported that nearly half (42 per cent) of the regions had some form of agriculture by 6,000 years ago, highlighting the prevalence of agricultural economies across the globe.
- Moreover, these results indicate that the onset of agriculture was earlier and more widespread than suggested in the most common global reconstruction of land-use history, the History Database of the Global Environment.
- This is important because climate scientists often use this database of past conditions to estimate future climate change; according to our research it may be underestimating land-use-associated climate effects.
- Hunting and foraging was generally replaced by pastoralism (raising animals such as cows and sheep for food and other resources) and agriculture in most places, though there were exceptions.
- In a few areas, reversals occurred and agriculture did not simply replace foraging but merged with it and coexisted side by side for some time.
More deeper roots
- Global archaeological data show that human transformation of environments began at different times in different regions and accelerated with the emergence of agriculture.
- Nevertheless, by 3,000 years ago, most of the planet was already transformed by hunter-gatherers, farmers and pastoralists.
- To guide this planet toward a better future, we need to understand how we got here.
- The message from archaeology is clear. It took thousands of years for the pristine planet of long ago to become the human planet of today.
- To build a more robust Earth science in the Anthropocene, the human sciences must play as central a role as the natural sciences do today.