S11: Climate Change
Required readings & video.
- GreenFacts (2007). Scientific facts on Climate Change. 2007 Update. Source document: Intergovernmental Panel on Climate Change (IPCC): "Fourth Assessment Report (AR4)" (2007). Summary & Details: GreenFacts (2007) (Level 1 – 2007 Update, 16 pp).
Available online at: http://www.greenfacts.org/en/climate-change-ar4/climate-change-ar4-greenfacts.pdf
- The Great Global Warming Swindle (first 32' out of 76'):
- Learn that the main focus of science is about testing hypothesis, and not about forcing to reach consensus on a topic.
- Learn the influence of mass media journalists with partial knowledge about hot and very relevant topics such as Climate Change.
- Learn the importance of being aware of the Data source and Time series analyzed in each case.
- Learn that differences can be statistically significant or not, and some time, conclusions can not be clearly drawn until new research clarifies the controversial previous results.
- Learn that the relationship between CO2 and Temperature might be different depending on the time scale considered.
- Learn the Scientific Consensus is not necessarily the same as Social Consensus about what to do to prevent the potential effects of Climatge Change if it continues to evolve as in the last few decades.
- Identify that there are a few reasons to consider that a new Ice Age might happen within the next decades or century in the upper half of the Northern Hemisphere.
- Identify the importance of using Carbon as a currency on our ecological impact and potential indicator to control many of our current problems in the World related to consumption of resources, pollution and Climate change.
1. Questions to answer during the session
- Q1) Is there an agreement among scientists that climate change is produced mainly by CO2 generated by humans? If not, what do the others say?
- Q2) Which is the closest Ice Age that happened in the Earth history or that might happen in the future respect to our current dates? How do you know that?
- Q3) Which is the main action that we need to promote in order to solve the current Climate Change problems and why?
2. "Recent" Evolution of Temperature
3. CO2 concentratation in the atmosphere
4. Selected pollutants and residence time in the atmosphere
5. Sources, sinks and storage of carbon
6. Q1: Is there an agreement among scientists that climate change is produced mainly by CO2 generated by humans?
- Some findings don’t fit with the official version:
Some of them shown also in the documentary "The Great Global Warming Swindle"
- Vostok Ice Core (400.000 years): Temp. rises around 800 years before the rise in CO2
- 1940-1970: CO2 rising after II world war, but temperatures went slightly down
- Troposphere is not warming as expected by the models in case rising temperatures were due to greenhouse gas emissions.
- Clouds and cosmic rays seem to be more important than reported in the IPCC report.
More research is needed before a unique scientific explanation can be drawn.
8. Global Warming: Is the debate over? (8')
ABC News report (former link: http://www.youtube.com/watch?v=3Y6jjk8BW7M - as of Fall 2013, it does not work)
See the video during the class.
9. Climate Change - Is CO2 the cause? (part 1) - Prof. Carter
Prof. Bob Carter (Melbourne, Sept. 8th, 2007).
http://www.youtube.com/watch?v=FOLkze-9GcI (min 2:30 - 5:30': "Is it warming or not?: It depends")
9.1. Is the Earth getting warmer? "It depends"
According to Prof. Bob Carter, upon available scientific data, it depends on the time frame that you look at in the history of the Earth:
- For the last 16 000 years (Since Pleistocene): warming
- For the last 10 000 years: cooling
(Holocene, the "Climatic Optimum", last stable warm period in the Earth)
- For the last 2 000 years: cooling, and at a faster rate.
- For the last 700 years: stasis (it included the Medieval Warm Period and the Little Ice Age)
- For the last 100 years: warming
- For the last years since 1999 (after "el Niño" effect in 1998): stasis
(as shown in the data provided at the talk held on Melbourne, Sept. 8th, 2007).
9.2. Q2: Closest Ice Ages that happened in the Earth history?
- Last (important) Ice Age (16 000 years ago, at the Pleistocene)
- Little-Ice age: 300-400 years ago.
When it can be repeated in the future respect to our current dates?
- "There is a good chance that we are heading towards another Ice Age again in a few decades", according to Solar Physicists cited by Bob Carter.
How could this happen?
One of the explanations is similar to what already happened in the past:
- "Ocean Conveyor" stopped by ceasing the deep water formation in the North Atlantic.
- This might happen (again) if a big enough amount of Ice Sheet (currently the one on top on Greenland) melts.
- Freshwater mixing with the colder water on the surface of the North Atlantic could make that water light enough to prevent it to go down to form deep water.
- Thus, the "Ocean conveyor" would stop to deliver heat from the tropics (through the Gulf current) to the Northern Hemisphere at the North Atlantic.
9.3. The Ocean Conveyor
9.4. The Gulf Stream and the Next Ice Age - Documentary (51')
- The Gulf Stream and the Next Ice Age is a one-hour documentary which explores the results of a recent American government report that believes the collapse of thermohaline circulation will take place around the year 2010 and impose a minor ice age on Europe. Could Dublin acquire a climate like Spitzberg, and London like that of Siberia?
The Gulf Stream is a powerful surface current, driven by the Trade Winds. Its origins lie in the Gulf of Mexico and it carries the tropical waters from the Florida Strait to the great banks of the United States, where it heads eastward, carrying its warm waters to the borders of the North Atlantic. As soon as the tropical waters hit the Arctic Ocean, they cool abruptly and plunge towards the abyssal zone to form a loop, known as "thermohaline circulation." Then, like an immense conveyor belt that slows down in the ocean depths, it sets out again southward to rejoin the beginning of the Gulf Stream.
9.5. Gulf Stream in (almost) real time
10. Extra info: Climate Change — isn't it natural? (5th video)
Potholer54: retired scientific journalist with very good quality divulgative videos on internet.
11. Q3) Which is the main action that we need to promote in order to solve the current Climate Change problems and why?
- Get informed by the mass media on the findings from all scientists (as publish their findings in peer-reviewed scientific journals).
- Also the findings from the skeptics about the official version from the IPCC report.
- Stop using Fossil Fuels as the main source of energy in our economies.
- switch to using sustainable sources of energy (Sun, Wind, Water ...)
- Prepare for it, on both ways, since warmings are happening already, and coolings might happen soon (decades? - centuries? 16 000 years?)
- reduce our consumption of energy ("stick to the annual solar income", as a reference: proposal by William McDonough)
12. More information
- The basics: The Hydrologic and Carbon Cycles: Always Recycle! - Crash Course
- Dissenting report to Anthropogenic Global Warming (AGW)
13. Practising System Analysis diagrams for the midterm