Final Exam is tomorrow!

1. Final Exam is tomorrow! • Final Exam is on Friday during class time, but in a different room: MEB246.

2. Last time: GeoengineeringWhat should you know? • What is SRM? • What is goal (from an energy balance perspective  should be able to start with GHE and move on to energy balance) • Sulfur injections into stratosphere is the most viable option for SRM right now • Sulfur lasts 1-2 years up there, removed by gravity. • Sulfur dioxide in the troposphere is a precursor to acid rain. Why not in the stratosphere? • Differences between temperature change with SRM v GHGs: • SRM would cool days more than nights, GHGs warm nights more than days. • They have different (and somewhat uncertain) effects on precipitation, but some evidence that volcanoes reduce precipitation globally. • Once we start SRM, if we stop then temperatures will rise very rapidly (10-20 years) back up to where they would’ve been. • Cloud in a bottle • need water vapor and CCN to make aerosols • Aerosols (in stratosphere or troposphere) have high albedo.

3. This time: SkepticsWhat should you know? • What are the Climategate emails? (don’t need to memorize any specifics) • You should be able to de-bunk some common skeptics arguments as long as they’re based on material that we’ve covered before today (we’ll go through these).

4. Typical Tactics of the Skeptics • “The Atmosphere isn’t warming”, or the data aren’t good enough to say it is warming • Not many in this camp anymore • “The warming is real, but it is natural variability” • Not many in this camp anymore • “The theory is flawed: there is no link between human activity and carbon dioxide increase in the atmosphere/warming” • A small but vocal group in this category • “The models are uncertain, so we don’t have to act” • A small but vocal group in this category

5. arguments against action • “The future warming will happen, but the projected changes are so small that it doesn’t matter” • some in this camp (including people who agree with the science) • “The future warming will happen, but the projected changes will have large impacts but it will be cheaper to clean it up in the future than to do something now” • A popular argument among skeptics (esp. those who fall into the category “have a lot to lose if we do something now”) • We have a lot of problems (malnutrition, lack of clean water, malaria, HIV/AIDS). These problems are more important/immediate that Global Warming • It is too expensive to prevent Global Warming: A tax on emitting carbon would increase the cost of energy derived from fossil fuel (the major source of energy for the developed and developing world) and cripple the global economy

6. Too expensive to solve (or cheaper to solve in the future) • Some economists argue that it is better to grow the economy now (with fossil fuels): • we will have more money in the future to solve the problem • “it is cheaper do deal with the consequences In the future than to act now to prevent the problem” • Early econ people in this group included Bill Nordhaus. • Other economists argue that it would be much cheaper to reduce emissions now than to cope with the cost of Global Warming • “The benefits of strong early action considerably outweigh the costs” (The Stern Report, 2006)

7. “Climate scientists promote global warming because it is good for business” • Facts (US): • Republicans have been more generous in funding for climate science than Democrats • Climate Change Research did much better under Bush I-III than under Clinton: We need more research, not action, because “Not enough is known” and “There is too much uncertainty” • Salary for university scientist is controlled by the University • Normal appointment is nine months; NSF and other agencies pay up to two more (at a rate fixed by the University) • The resources available to US scientists from coal and oil industries dwarf that from governmental agencies • Most of the climate scientists in the ‘skeptics’ category are funded by oil and gas companies, or by entities that oil and gas supports. For example, the American Petroleum Institute, the Competitive Enterprise Institute (more later) • There is little professional reward for engaging in applied sciences, such as illuminating the impacts of climate change. • Accolades, promotions and professional awards are dominated by disciplinary activities

8. “ClimateGate” • Thousands of emails between climate scientists (sent from 1996-2009) are stolen from the University of East Anglia • Damning excerpts demonstrating a cover up? http://www.youtube.com/watch?v=DNbxYVa2VjA

9. National poll from Yale University on detection of global warming: Recently, you may have noticed that global warming has been getting some attention in the news. Global warming refers to the idea that the world’s average temperature has been increasing over the last 150 years, may be increasing more in the future, and that the world’s climate may change as a result. What do you think? Do you think that global warming is happening?

10. Damning Excerpts (?) from the Stolen Emails From: Phil Jones. To: Many. Nov 16, 1999 "I've just completed Mike's Nature [the science journal] trick of adding in the real temps to each series for the last 20 years (ie, from 1981 onwards) and from 1961 for Keith's to hide the decline." Reconstructions of Northern Hemisphere Temperature (1000-1999AD) Tree rings show cooling from 1950 to the end of tree records (1960-80), while the instrumental data shows warming continued thru the time this email was sent (1999). Called the “tree ring divergence” problem (tree ring width no longer tracks temperature), it has been discussed in the peer reviewed literature since 1998.

11. Damning Excerpts (?) from the Stolen Emails From: Phil Jones. To: Many. Nov 16, 1999 "I've just completed Mike's Nature [the science journal] trick of adding in the real temps to each series for the last 20 years (ie, from 1981 onwards) and from 1961 for Keith's to hide the decline.” Skeptics cite this email as evidence that data was manipulated to mask the fact that global temperatures are falling. Blending the instrumental temperature data to extend the tree ring reconstruction to 1999 is “the trick” that doesn’t “hide the decline” in temperature from 1950-75.

12. Global Average Temperature Record (instrumental) • Is the Earth cooling down? Averaged over several decades (ie, ignoring natural variability): no! 2009 Source: NOAA

13. Damning Excerpts (?) from the Stolen Emails From:Phil Jones. To: Many. March 11, 2003 “I will be emailing the journal to tell them I’m having nothing more to do with it until they rid themselves of this troublesome editor.” This was in response to a paper by Soon and Baliunas (2003) that was published in “Climate Research”. The publisher did would not publish an editorial from the incoming editor stating the review process had failed and the paper had serious methodological problems in the paper that were raised by reviewers. As a result, four editorial board members resigned, and the paper lives in infamy because the methodological problems invalidated the results and conclusions of the paper. From Phil Jones To: Michael Mann (Pennsylvania State University). July 8, 2004 "I can't see either of these papers being in the next IPCC report. Kevin and I will keep them out somehow — even if we have to redefine what the peer-review literature is!” Nobody can redefine the peer-review processes. The only significant modification to the peer review process in the past 30 years has been to make the review process public (enabled by the www). This comment reflected Jones’ distaste for two poor papers that were being considered for discussion in the IPCC AR4 report. In the end, both were referenced in the report.

14. Damning Excerpts (?) from the Stolen Emails From: Kevin Trenberth (US National Center for Atmospheric Research). To: Michael Mann. Oct 12, 2009 "The fact is that we can't account for the lack of warming at the moment and it is a travesty that we can't... Our observing system is inadequate” Trenberth is arguing for a better climate observing system so that short term (year to year) changes in climate and energy fluxes due to natural variability can be better distinguished from longer term (forced) changes. From: Michael Mann. To: Phil Jones and Gabi Hegerl (University of Edinburgh). Date: Aug 10, 2004 "Phil and I are likely to have to respond to more crap criticisms from the idiots in the near future.” Mike Mann (lead author on the “hockey stick” temperature diagram reconstruction) is expressing frustration at being hounded by skeptics, including being called to testify in the senate, numerous requests for his data and models using the freedom of information act, etc.

15. The Northern Hemisphere Temperature:1400-2000 (the “Hockey Stick”) • Mann, Bradley and Hughes (1999) presented a record of the northern hemisphere average temperature and concluded • the planet is warmer than anytime in the past ~1000 years • The rate of warming accelerated from about 1850 to present • McIntyre (mining) and McKitrick (economist) noted in 2005 the methodology that MBH used is prone to exaggerating the Hockey Stick shape of the curve (the abrupt warming). Mann et al (1999); Also IPCC 2001

16. The Northern Hemisphere Temperature:1400-2000 (the “Hockey Stick”) Original MBH99 The way MM say it should be calculated The 20th Century is very likely the warmest time since (at least) 1600, regardless of the nuances in how the calculation is done after Wahl and Amman (2006)

17. The Northern Hemisphere Temperature:1400-2000 (the “Hockey Stick”) • The National Academy of Sciences reviewed this issue and concluded in a special report: “It can be said with a high level of confidence that global mean surface temperature was higher during the last few decades of the 20th century than during any comparable period during the preceding four centuries. This statement is justified by the consistency of the evidence from a wide variety of geographically diverse proxies.” “Less confidence can be placed in large-scale surface temperature reconstructions for the period from A.D. 900 to 1600. Presently available proxy evidence indicates that temperatures at many, but not all, individual locations were higher during the past 25 years than during any period of comparable length since A.D. 900. The uncertainties associated with reconstructing hemispheric mean or global mean temperatures from these data increase substantially backward in time through this period and are not yet fully quantified. NAS/NRC 2006

18. The Northern Hemisphere Temperature:1400-2000 (the “Hockey Stick”) Each color line is a reconstruction from a separate group using different data and techniques for reconstruction IPCC 2007 The 20th Century is very likely the warmest time since (at least) 1600, regardless of the nuances in how the calculation is done

19. The Northern Hemisphere Temperature:1400-2000 (the “Hockey Stick”) Some commentary: • Mann et all (mostly Mann) were wrong in that for a long time, they wouldn’t accept McIntyre and McKitrick’s (MM) criticism of their methods • The calculations re-done MM’s way -- and in other ways -- show the same results as presented by Mann et al.: the 20th Century is warmer than anytime since at least 1600, and probably much earlier. • MM conveniently ignore these new calculations.

20. The Northern Hemisphere Temperature:1400-2000 (the “Hockey Stick”) Some commentary (cont): • The ‘hockey stick’ graph became iconic, and the argument over the details of how it was constructed took center stage • Fueled by the egos (Mann) and interests (MM) of those involved • The overwhelming evidence for unusual warming in the 20th century was lost in the noise. • In the short term, the “skeptics” were successful in deflecting attention away from the main conclusions and ramifications from the science

21. Damning Excerpts (?) from the Stolen Emails From:Phil Jones. To: Mike Mann “Mike, Can you delete any emails you may have had with Keith re AR4? Keith will do likewise. He’s not in at the moment – minor family crisis. Can you also email Gene and get him to do the same? I don’t have his new email address. We will be getting Caspar to do likewise..” This is claimed by skeptics to be in response to a request under the Freedom of Information Act to release email, although there is no discussion of what material should be deleted, or why. Deleting email to avoid a FOI request doesn’t make a lot of sense but if true this is wrong.

22. Summary of Content/Meaning of the Stolen Emails • Thousands of emails sent & received from 1996-2009 • None of which change the state of the science in any way (e.g., the science presented in the 2001 and 2007 IPCC reports) • The instrumental temperature record for the 20th Century has been calculated independently by four different groups from US, UK and Japan: each uses a different analysis technique and each finds the same answers: • The global averaged surface temperature has increased 0.85C in the past 100 years, and all find the same year-to-year variability about this trend • The 1000 year proxy record of northern hemisphere temperature (the hockey stick graph) has been calculated by 20 different groups and examined by the National Academy of Sciences • All find that the warmth of the 20th century is unique in the past 400 years and probably in the past 1000 years • These results are also consistent with other proxy data (e.g., borehole temperature measurements) For a balanced scientific summary of the content of the stolen emails, see www.realclimate.org