why has Life sustained on the earth for thousands of years
Answers
Answer:
The oxygen and carbon dioxide in the lower layers of the troposphere (that touches Earth) allow life to exist as organisms can respire and plants can photosynthesise. The atmosphere also helps to keep the Earth warm by trapping solar energy. The atmosphere protects life from too much UV radiation from the Sun
Answer:
The rich tapestry of life on our planet is the outcome of over 3.5 billion years of evolutionary history. It has been shaped by forces such as changes in the planet's crust, ice ages, fire, and interaction among species. Now, it is increasingly being altered by humans. From the dawn of agriculture, some 10,000 years ago, through the Industrial Revolution of the past three centuries, we have reshaped our landscapes on an ever-larger and lasting scale. We have moved from hacking down trees with stone tools to literally moving mountains to mine the Earth's resources. Old ways of harvesting are being replaced by more intensive technologies, often without controls to prevent over-harvesting. For example, fisheries that have fed communities for centuries have been depleted in a few years by huge, sonar-guided ships using nets big enough to swallow a dozen jumbo jets at a time. By consuming ever more of nature's resources, we have gained more abundant food and better shelter, sanitation, and health care, but these gains are often accompanied by increasing environmental degradation that may be followed by declines in local economies and the societies they supported