Since the Industrial Revolution, leading scientists believe that man has been responsible for releasing large amounts of greenhouse gasses into the atmosphere. The most well known of these gases is carbon dioxide. This is realeased (along with methane and carbon monoxide) during combustion/burning of fossil fuels.
Due to this ‘release’, greenhouse gas levels are the highest they have been since about 100 000 years ago, or two ice ages ago.
We can tell from trapped air bubbles in ice cores, taken from the ice sheets, in Antarctica and Greenland what the CO2 concentrations were going back roughly a million years (the most famous of these being the Vostok Ice Core). Scientists are able to extract these air bubbles, measure what the gas concentrations are, and work out the age of the bubble from the oxygen ratio in the surrounding ice. (See the Two-Mile Time Machine book or Vostok Ice Core database paper below)
In the last week, Nasa have released a report saying that most of the Glaciers on the West Antarctic Ice sheet have retreated past the point of no return, and climate change is the culprit. The loss of these glaciers could lead to a collapse of a large portion of the West Antarctic ice sheet, which in turn could lead to a sea level rise of several metres (according to some reports). This could take a decade, it could take 1000 years, but scientists are now adamant that it is happening.
Here are some books on climate change and ice sheets:
Ice, mice and men : the issues facing our far south / Geoff Simmons and Gareth Morgan with John McCrystal.
“Our far south is packed with history and wildlife, and is renowned for its breathtaking and photogenic beauty. But does our appreciation of the region run more than skin deep? Do Kiwis really understand how important the region is and what issues are facing it? In February 2012, Gareth Morgan trapped ten of New Zealand’s top experts on the region in a boat with 40 ordinary Kiwis for a month. Together with Geoff Simmons, he grilled them about the issues facing the region and this book is the result. What they found was startling. Our Far South – that part of New Zealand that extends from Stewart Island almost without interruption to the South Pole – harbours precious wildlife and is the engine room of the world’s oceans and climate. We are blessed to live in this unique part of the world, but we also have a huge responsibility to look after it. This book looks at the three ways we risk inflicting long-term, even permanent harm, on this precious and fragile region. The race to exploit resources has been underway for three centuries, and may be poised to escalate. Pressure from human activity may be threatening biodiversity and even the survival of species. And looming ever larger is the threat of climate change. Damage done to our far south will have profound implications, both for New Zealand and right across the globe.” (Cover)
The two-mile time machine : ice cores, abrupt climate change, and our future / Richard B. Alley.
“Richard Alley, one of the world’s leading climate researchers, tells the fascinating history of global climate changes as revealed by reading the annual rings of ice from cores drilled in Greenland. In the 1990s he and his colleagues made headlines with the discovery that the last ice age came to an abrupt end over a period of only three years. Here Alley offers the first popular account of the wildly fluctuating climate that characterized most of prehistory–long deep freezes alternating briefly with mild conditions–and explains that we humans have experienced an unusually temperate climate. But, he warns, our comfortable environment could come to an end in a matter of years.” (Amazon.com)
The Goldilocks planet : the four billion year story of Earth’s climate / Jan Zalasiewicz & Mark Williams.
“The climate change debate has long been dominated by climatologists, politicians, and economists, but the contributions of geologists to an understanding of this issue have been underreported. In The Goldilocks Planet, geologists Zalasiewicz and Williams (both, Univ. of Leicester, UK) synthesize a vast body of work on paleoenvironmental reconstruction and paleoclimate through geologic time. They identify the greenhouse and icehouse episodes from the Archaean eon to the present and explain how these conditions waxed and waned. The authors concentrate on the warming and cooling episodes from the Pliocene period (prior to the Pleistocene glaciations) to date and use substantial and diverse recent research findings. The Earth is now thought to be headed to that Pliocene warming benchmark. Zalasiewicz and Williams provide simple explanations of the astronomical, geological, chemical, and geographic factors that weave into the natural greenhouse and icehouse episodes. This scholarly book is well written and documented, and the authors make good use of analogies to convey the scale and importance of the processes at work. Along the way, readers also learn about the scientists in many fields who have contributed to the development of these ideas.” (CHOICE)
Here is an article from our Databases on the Vostok Ice Core