Lifestyle Environment 04 Nov 2017 So, let's talk ...
The writer is an author, speaker, trainer, consultant, an entrepreneur and an expert in applied sustainability. Visit: www.CBRamkumar.com.

So, let's talk green: The ‘Ice core’ story of Claude Lorius

Published Nov 4, 2017, 1:50 am IST
Updated Nov 4, 2017, 7:08 am IST
Between 23,000 and 9,000 years ago, the amount of Co2 in the atmosphere increased by 80 ppm, rising from 180 to 260 ppm.
Representational image
 Representational image

In all of science, one name stands out as the holy oracle of climate change and that name is Claude Lorius. He is known today a climate change and glacial oracle. In 1963 when defending his physics Ph.D. thesis, he described how past temperatures can be reconstructed using measurements of oxygen and hydrogen isotopes in ice. He hypothesized that tiny air bubbles in the ice samples must represent the composition of atmospheric gases at the time of encapsulation.  With this he developed the capability to look into the past like no man has ever done - he could see thousands of years into the past by examining ice cores from the Antarctic and predict the future of our planet. Over his 60 year career, he took part in 22 expeditions into the Antarctic, collecting ice cores that would tell the tale of Earth's climate history. In the 70's, Lorius and his colleagues collected at least three tons of ice cores during 20 expeditions, and demonstrated how to discover temperatures that prevailed in the planet hundreds and thousands of years ago. 

Since then, many more records have been measured including the longest yet recovered during the European Project for Ice Coring in Antarctica Dome C, which spans the past 740 000 years. These records provide proof that what scientists are seeing today is way more alarming when compared to the past eight swings between ice ages, known as glacials, and warm periods. More details were revealed in the World Meteorological Organisation's (WMO) Annual Greenhouse Gas Bulletin, published by the Atmospheric Environment and Research Division of WMO's Research Department every year. It reports the latest trends and atmospheric burdens of the most influential, greenhouse gases; carbon dioxide (Co2), methane, and nitrous oxide. These three major gases alone contribute about 88% of the increase in temperatures by changes in greenhouse gases occurring since 1750, the beginning of the industrial age. The latest Green House Gas bulletin released last week, details how some 23 000 years ago, Earth emerged from the last ice age, as atmospheric Co2 concentrations and temperature began to rise.

 

Between 23,000 and 9,000 years ago, the amount of Co2 in the atmosphere increased by 80 ppm, rising from 180 to 260 ppm. The West Antarctica ice core record reveals three distinct types of Co2 variability during this time period. A slow increase in Co2 at about 10 ppm per 1,000 years between 18,000 and 13 000 years ago, an abrupt increase of 10-15 ppm over 100-200 years have been seen at three time periods- 16,000, 15,000 and 12,000 years ago, and a stable Co2 plateau that lasted about 1,000-1,500 years.  But when we look at the present state of affairs, the GHGB says that the amount of Co2 in the earth's atmosphere grew at record rate in 2016 to a level not seen for millions of years. Atmospheric concentrations of Co2, hit 403.3 ppm, up from 400 ppm in 2015. This growth rate was 50% faster than the average over the past decade, driving Co2 levels 45% above pre-industrial levels and further outside the range of 180-280 ppm seen in cycles of ice ages and warmer periods!  The last time Co2 levels reached 400 ppm was 3-5 million years ago, in the mid-Pliocene era.

 

During that period, global mean surface temperatures were 2-3°C warmer than today, ice sheets in Greenland and West Antarctica melted and even parts of East Antarctica's ice retreated. All this combined caused the sea level to rise 10-20 meters higher than that today! The Guardian describes Claude Lorius as 'an intriguing blend of explorer, scientist and survivor', and the Franklin Institute described him as an 'advocate for the planet and by extension, the human race.' I describe him as a story teller. He got the ice cores that he dug out to tell us stories of the planet from thousands of years ago. It is now revealing that the period we are living in, is turning to be a horror story - unless all of humanity collectively starts to re write the script.  Can we change the ice core story, that says that sea levels can rise up to 10-20 meters like it did millions of years ago? Are we capable of stopping the effects of climate change by reducing the emissions of greenhouse gases that come from burning fossil fuels?  Humanity needs to collectively author a better script for the sake of the planet….for the sake of the human race!

 

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