Past climate change - was this weeks theme. How can looking backwards help us look forwards and understand climate change? Clearly understand the markers which can be used to identify significant climatic events in the planets past not to mention to understand how factors such as carbon dioxide concentration can be related to global average temperature all help in construction models to predict the future climate of the planet.
How can ice cores provide a record of atmospheric composition?
Ice cores are an interesting scientific measure that we can use to sample the climate composition, temperature, airborne particulates and local wind patterns in an historical context.
As the cores contain dissolved gases, differing isotope ratios and material textures we can use these features as a measures of atmospheric gases, temperature, date and seasonal markers. The particulates captured by snow fall can provide information about volcanic activity as well as pollen. This giving information regarding volcano eruptions and seasonal growth patterns. All this information stored in stratified chronological layers.
Other Review Questions
1. What are the most important themes you have learned this week?
I quite like the snowball earth. It reminds me of the snowdrop analogy to positive feedback mechanisms. In fact overall understanding positive and negative feedback mechanisms as well as tipping points are going to be crucial in realistically developing solutions to climate change. A case in point is the simple act of reducing carbon soot emissions from cars and factories. Although this has made the air much better for individuals it has had the effect of increasing our average temperature, particularly in the northern hemisphere, by removing the reflective and radiative effects of the particulates in the atmosphere. It is also true that it has reduce soot precipitation on the polar ice caps and this has lead to an increased albedo from the snow which had been reduced by the carbon particulates.
2. What aspect of this week did you find difficult?
The 400 ppm section. Yes we hit 400 ppm but we have technically now dropped below 400 ppm. Not that it makes much difference but I think focusing on these particular numbers do not really help people understand the consequences of GHGs.
3. What did you find most interesting? And why?
The snowball earth and feedback mechanisms as mentioned above. That and the fact you pointed to a dodgey youtube video rip of the BBC documentary!
4. Was there something that you learned this week that prompted you to do your own research?
5. Are there any web sites or other online resource that you found particularly useful in furthering your knowledge and understanding?