Rapid Climate Change – not for the First Time
Quick reflection on the Holocene
Here in the Holocene, the name given to epoch that represents the last 10,000 years or so our planet is experiencing a period of relatively cold weather in geological terms. The planet has steadily been getting cooler since the end of the Mesozoic (65 million years ago). It is true, if a graph of average global temperatures were drawn, the line representing temperature would not always slope downwards to the present, for example, the world got considerably warmer during the the early Eocene with global temperatures estimated to be 2 degrees Celsius higher than in the Cretaceous. However, there has been a trend over the last 65 million years or so for the average temperature on the planet to fall. Despite fears regarding global warming and climate change, the average global temperature is 14 degrees Celsius, compared to nearly 19 degrees 15 million years ago.
Climate change has an enormous impact on life, the difference between the changes we are seeing today and some of the changes in the past is the speed of the change. If scientific predictions are correct, global temperatures could rise by about as much as 5 degrees over 100 years. A radical change, one that would have devastating consequences for much of the planet. The geological time period we are living in today is called the Quaternary, this is divided into two epochs, the Pleistocene which began about 1.8 million years ago and the Holocene (recent time, the last 10,000 years). The Quaternary was divided into two parts, with a boundary at 10,000 years ago because it was then that a major thaw in the world’s ice sheets occurred, taking no more than 15-50 years. This dramatic warming led to a number of extinctions, particularly amongst large mammals and other mega fauna. Since this sudden warming up, the Earth’s climate has actually been more stable than during any other 10,000 year interval in at least the last 200,000 years.
Ancient Landscapes Under Threat Due to Climate Change
Picture credit: Everything Dinosaur
This relatively stable period of world weather, has enabled the human species to flourish, soon our population will exceed 7 billion. Our numbers and the subsequent demand for finite resources plus the affect our species is having on the environment could spell trouble ahead, not just for the so called vulnerable species such as some of the large mammals we share the Earth with, but remember we are a large mammal too.