LIFE ON Earth began 3.5 billion years ago. But the life as we know it was shaped in the Cenozoic epoch, which began only 66 million years ago and continues to this day. During this period, mammals, insects, birds and flowering plants flourished on land, while fish, corals and molluscs thrived in the ocean.
Earth transitioned from a hothouse with no glaciers to a cooler one with ice sheets at the poles. However, between 14 and 17 million years ago, known as the Miocene Climatic Optimum (MCO) period, temperatures soared (around 10°C higher than today) and carbon dioxide (CO₂) levels rose to 1,000 parts per million (PPM) against the current 419 PPM, leading to the disappearance of glacial masses and several species.
Several such episodes of global warming in the past have always baffled scientists. Humans were not responsible for this warming as they arrived about 15 million years after MCO, Timothy Herbert, a scientist at Brown University, tells Down To Earth (DTE). So what triggered these changes? Understanding these factors is important at a time when human activities are already spewing greenhouse gases into the atmosphere, pushing the planet towards a climate tipping point.
この記事は Down To Earth の September 01, 2022 版に掲載されています。
7 日間の Magzter GOLD 無料トライアルを開始して、何千もの厳選されたプレミアム ストーリー、9,000 以上の雑誌や新聞にアクセスしてください。
すでに購読者です ? サインイン
この記事は Down To Earth の September 01, 2022 版に掲載されています。
7 日間の Magzter GOLD 無料トライアルを開始して、何千もの厳選されたプレミアム ストーリー、9,000 以上の雑誌や新聞にアクセスしてください。
すでに購読者です? サインイン
A SPRIG TO CARE FOR
Punarnava, a perennial herb, is easy to grow and has huge health benefits
DIGGING A DISASTER
Soapstone mining near Dabti Vijaypur village has caused many residents to migrate.
REVIEW THE TREATMENT
Several faecal sludge treatment plants in Uttar Pradesh suffer from design flaws that make the treatment process both expensive and inefficient
MAKE STEEL SUSTAINABLE
As India works to double its GDP by 2030, its steel industry must balance growth with sustainability. By embracing policies like the Steel Scrap Recycling Policy 2019 and adopting green technologies, India is paving the way for a more sustainable future in steel production
Can ANRF pull off the impossible for India?
Anusandhan National Research Foundation is expected to reorient India's innovation goals but funding issues, old mindsets remain a drag
TROUBLED WOODS
Forests are a great bulwark against climate change. But this is fast changing. AKSHIT SANGOMLA travels through some of the pristine patches of the Western Ghats to explore how natural disturbances triggered by global warming now threaten the forest health
BLINDING GLOW
The science is clear: increased illumination has damaging consequences for the health of humans, animals and plants. It’s time governments introduced policies to protect the natural darkness and improved the quality of outdoor lighting.
GROUND REALITY
What happens when the soil loses the ability to grow healthy, high-yield crops on its own?
GM POLICY MUST BE FARMER CENTRIC
On July 23, the Supreme Court of India directed the Union government to develop a national policy on genetically modified (GM) crops for research, cultivation, trade and commerce through public consultation.
Vinchurni's Gandhi
A 96-year-old farmer transforms barren land into a thriving forest in drought-prone region of Satara
