The Changing Earth - The Experts

"Reaching the 400 ppm mark should be a reminder for us that carbon dioxide levels have been shooting up at an alarming rate in the recent past due to human activity. 
"Levels that high have only been reached during the Pliocene era, when temperatures and sea level were higher. 
"However, Earth's climate had never had to deal with such a drastic change as the current increase, which is, therefore, likely to have unexpected implications for our environment."
– Dr. Carmen Boening



 Scientists know that recent climate change is caused by human activities.
 

 The speed of the current climate change is faster than most past warming events, making it more difficult for human societies and the natural world to adapt. 

 The key ideas are explained in a publication called -

Climate Change: Evidence and Causes

It was put together by the Royal Society and the National Academy of Sciences, their equivalent in the USA.
The Royal Society is a self-governing Fellowship of many of the world’s most distinguished scientists. 

 Professor Tim Palmer FRS, Royal Society Research Professor in Climate Physics, University of Oxford

“The threat of dangerous man-made changes to global climate is quite unequivocal. 
It follows that if we want to reduce this threat, we must cut our emissions of greenhouse gases."

 Professor John Shepherd FRS, Ocean & Earth Science, University of Southampton:


“The evidence is very clear that the world is warming, and that human activities are the main cause. 
Natural changes and fluctuations do occur but they are relatively small."

 Professor Joanna Haigh CBE FRS, Professor of Atmospheric Physics, Imperial College London


 “The concentration of carbon dioxide in the Earth’s atmosphere now exceeds anything it has experienced in the past 3 million years and its continuing upward trend is almost certain to result in further global warming."

Professor Sir Brian Hoskins FRS, Director of the Grantham Institute for Climate Change at Imperial College London:

“The evidence of changes in many different aspects of the climate system, from the ice sheets to the deep ocean, shows that climate change is happening.   
To reduce the serious risks posed by increasing changes in the climate, we need to redouble our efforts globally to limit carbon dioxide and other greenhouse gas emissions.”

The Royal Society has also published a "Short Guide to Climate Change" 

Another organisation offering an important document is the Geological Society of London.

                                  
The Geological Society of London say -

This rate of increase of CO2 is unprecedented.....

 even in comparison with the massive injection of carbon into the atmosphere 55 million years ago that led to the major PETM warming event....

 and is likely to lead to a similar rise in both temperature and sea level. 

From.....

Climate Change: Evidence from the Geological Record

Another expert who is good at explaining climate change is 



Dr Marshall Shepherd.

Popular posts from this blog

Climate Change - The link with mass extinctions

Image
What is the worst-case scenario for climate change? The geological record shows that when the atmosphere suddenly changes, there are big effects on living things. Five major  mass extinction  events are recorded in the rock record of the last 600 million years. The biggest extinction was at the end of the  Permian , around 252 million years ago. It is called the  End-Permian mass extinction. Only about 8% of species survived to live on in the Triassic Period. This photo shows geologists investigating tilted sedimentary rocks at Shangsi in South China. Triassic rocks (at the top right) lie over the older Permian rocks. Each mass extinction in the rocks matches with a change in the chemistry of the rocks called a ' carbon excursion '. Some of the carbon excursions are 'negative CEs' and some are 'positive CEs'. Negative CEs  indicate that lots of gaseous carbon compounds escaped into the air, causing warming. These are sometime
Read more

Climate Change - The Greenhouse Effect

Image
What do scientists mean by the " Greenhouse Effect "? When the Sun's energy arrives at the Earth, it travels through the air. Some is reflected back to space, but some hits the Earth and warms it. The warm Earth gives off  infrared radiation  with various wavelengths.   Some of those waves can pass back out of the air to space, but some are absorbed by certain gases in the air. The gases then re-emit the energy into the air. If there are more of those gases, less heat escapes into space. An extreme case has happened on Venus. Concentrated  'greenhouse gases'  on Venus have caused the surface temperature to rise to 735  Kelvin  (462 degrees C; around 900 degrees F) Carbon dioxide levels in the atmosphere have risen quickly  since people began burning large quantities of fossil fuels. There was carbon dioxide in the air before that, at around 270 parts per million. Without any carbon dioxide, the Earth would be very cold.
Read more

Climate Change - Coal and carbon dioxide

Image
Coal, oil and natural gas are  fossil fuels . When they are burned, they  change the Earth's atmosphere. How is that possible?       C oal  is a good example. Coal was formed  hundreds of millions of years ago . Geologists say that a three-metre (10-foot) coal seam took between  12,000 and 60,000 years  to form . Ancient trees and other plants lived, died and were fossilised. All those plants took  carbon dioxide  out of the atmosphere.  Some larger coal seams are, for example, 10 metres thick. They took around  40,000 years to form,  but have been mined and burned in a little over  100 years. The fastest rise of CO 2  in the air seen in   the ice core record (800,000 years)  is  20 ppm in 1000 years. The CO 2  level in the atmosphere is now rising at around  20 ppm per decade . The  carbon  joins up with  oxygen  when it burns. Each carbon atom joins with two oxygen atoms to make a  carbon dioxide molecule .  As a result, oxygen concentration i
Read more