Global Climate Change A Heated Debate

Transcription

1 Global Climate Change A Heated Debate

2

3 A Heated Debate Who are the real skeptics and who are the contrarians? sceptic or US skeptic [skep-tik] Noun 1. a person who habitually doubts generally accepted beliefs. doubter, cynic, scoffer, disbeliever

4 A Heated Debate Who are the real skeptics and who are the contrarians? In ordinary usage: Skepticism (Greek: 'σκέπτομαι' skeptomai, to look about, to consider; (a) an attitude of doubt or a disposition to incredulity either in general or toward a particular object; (b) the doctrine that true knowledge or knowledge in a particular area is uncertain; or

5 A Heated Debate Who are the real sceptics and who are the contrarians? Considering the rigor of the scientific method, science itself may simply be thought of as an organized form of skepticism. The scientific skeptic generally accepts claims that are in his/her view likely to be true based on testable hypotheses and critical thinking.

6 A Heated Debate Who are the real sceptics and who are the contrarians? Genuine skeptics seek to apply doubt impartially and systematically, forming their beliefs through a balanced evaluation of the evidence. Bogus skeptics cherry pick evidence on the basis of a preexisting belief, seizing on data, that appears to support their position, while declaring themselves "skeptical" of any evidence, however compelling, that undermines it.

7 A Heated Debate Who are the real sceptics and who are the contrarians? According to Richard Wilson, who highlights the phenomenon in his book Don't Get Fooled Again (2008), the characteristic feature of bogus skepticism is that it "centres not on an impartial search for the truth, but on the defence of a preconceived ideological position".

8 A Heated Debate The Pew Research Center past polls on public attitudes towards climate change. The proportion of Americans who say that the earth is getting warmer has decreased modestly since January 2007, mostly because of a decline among Republicans. And what happened in 2009?

9 A Heated Debate

10 And smoking isn t bad for your health

11 The mid 1950 s

12

13

14 Smoke, Mirrors and Hot Air Jan 2007 Union of Concerned Scientists In an effort to deceive the public about the reality of global warming, ExxonMobil has underwritten the most sophisticated and most successful disinformation campaign since the tobacco industry misled the public about the scientific evidence linking smoking to lung cancer and heart disease. The report documents that, despite the scientific consensus about the fundamental understanding that global warming is caused by carbon dioxide and other heat-trapping emissions, Exxon-Mobil has funneled about $16 million between 1998 and 2005 to a network of ideological and advocacy organizations that manufacture uncertainty on the issue.

15 Manufactured uncertainty by raising doubts about even the most indisputable scientific evidence. Promoted scientific spokespeople who misrepresent peer-reviewed scientific findings in their attempts to persuade the media and the public that there is still serious debate among scientists that burning fossil fuels has contributed to global warming and that human-caused warming will have serious consequences. Attempted to shift the focus away from meaningful action on global warming with misleading charges about the need for sound science. Union of Concerned Scientists

16 A Heated Debate human beings are now carrying out a large scale geophysical experiment of a kind that could not have happened in the past nor be reproduced in the future. Within a few centuries we are returning to the atmosphere and oceans the concentrated carbon stored in sedimentary rocks over hundreds of millions of years The experiment if adequately documented may yield a far-reaching insight into the processes determining weather and climate Rodger Revelle and Hans Suess, Tellus, 1957

17 A Heated Debate Arguments and Myths in the Debate The atmosphere isn t warming The warming is due to natural variation The amount of warming is insignificant The benefits will outweigh the problems Technology will come to the rescue We shouldn t wreck the economy If they can t predict the weather for the next month, how can they predict the climate a hundred years from now?

18 A Heated Debate What If the Hockey Stick Were Wrong?

19 A Heated Debate The hockey stick reconstruction of temperatures of the past millennium has attracted much attention partly as it was high-lighted in the 2001 IPCC report as one of the important new results since the previous IPCC report of 1995, and partly as it has become the focus of a number of challenges.

20 A Heated Debate Discussion about the hockey stick is conducted with considerable fervor in the public media, where this curve is often presented as if it were a proof, or even the most important proof, of anthropogenic influence on climate.

21 A Heated Debate Let us assume that medieval temperatures after all had been warmer than the present. Even that would tell us nothing about anthropogenic climate change. The famous conclusion of the IPCC, The balance of evidence suggests that there is a discernible human influence on global climate, does not depend on any reconstruction for the past millennium.

22 A Heated Debate It depends on a detailed analysis of 20th Century data. In fact, this conclusion is from the 1995 IPCC report, and thus predates the existence of quantitative proxy reconstructions like the hockey stick.

23 A Heated Debate The main reason for concern about anthropogenic climate change is not that we can already see it (although we can). The main reason is twofold. (1) Carbon dioxide and other greenhouse gases are increasing rapidly in the atmosphere due to human activity. This is a measured fact not even disputed by staunch climate skeptics.

24 A Heated Debate (2) Any increase in carbon dioxide and other greenhouse gases will change the radiation balance of the Earth and increase surface temperatures. This is basic and undisputed physics that has been known for over a hundred years.

25 A Heated Debate But how strong is this warming effect? That is the only fundamental doubt about anthropogenic climate change that can still be legitimately debated. Climatologists describe this in terms of the climate sensitivity, the warming that results in equilibrium from a doubling of CO2.

26 A Heated Debate But how strong is this warming effect? The IPCC gives the uncertainty range as ºC. Only if this is wrong, and the true value is lower, can we escape the fact that unabated emissions of greenhouse gases will lead to the warming projected by the IPCC.

27 A Heated Debate Chances for that are not good. A 2005 large uncertainty analysis that appeared in Nature shows that it is very difficult to get a climate sensitivity below 2 ºC in a climate model, no matter how one changes the parameters. And climate history, with its Ice Ages and other large changes, also speaks strongly against low climate sensitivity.

28 A Heated Debate The discussions about the past millennium are not discussions about whether humans are changing climate; neither do they affect our projections for the future. In fact, if humanity takes no action and this century will bring a temperature rise of 2 ºC, 3 ºC or even more, the current discussions over whether the 14th Century was a few tenths of a degree warmer or the 17th a few tenths cooler than previously thought will look rather academic.

29 A Heated Debate The scientist s dilemma: speak out or keep quiet? James Hansen NOAA

30 Climate Threat to the Planet:* Implications for Energy Policy and Intergenerational Justice Jim Hansen December 17, 2008 Bjerknes Lecture, American Geophysical Union San Francisco, California *Any Policy-Related Statements are Personal Opinion

31 Empirical Climate Sensitivity 3 0.5C for 2XCO 2 1. Includes all fast-feedbacks* *water vapor, clouds, aerosols, surface albedo (Note: aerosol feedback included) 2. Paleoclimate data yields precise results 3. Relevant to today s climate sensitivity generally depends on climate state

32 Climate Change Depends on 1. Equilibrium Climate Sensitivity Nailed: it s 3 C for 2xCO 2 2. Forcings: Human & Natural 3. Response Time (Ocean Inertia)

33 Climate forcing agents in the industrial era. Aerosols cause a net negative forcing, via their direct effect on sunlight and their effect on cloud properties, but the error bars are huge. Source: Hansen et al., JGR, 110, D18104, 2005.

34 Greenhouse Gas, Aerosol & Net Climate Forcing Greenhouse gas forcing is accurately known (~3 W/m 2 ), but aerosol forcing is very uncertain. Source: IPCC (2007)

35 Sophie explains 2 Watts of forcing to brother Connor Sophie Explains GH Warming: It s 2 W/m 2 Forcing. Connor only counts 1 Watt

36 Greenhouse Gas, Aerosol & Net Climate Forcing Connor s +1 Watt Sophie s +2 Watts Greenhouse gas forcing is accurately known (~3 W/m2), but aerosol forcing is very uncertain. Source: IPCC (2007)

37

38 Why is this important, 1 Watt or 2 Watts? Because of the Faustian bargain that humanity has made. If Sophie is right, aerosols have only reduced the greenhouse gas forcing from 3 W to 2 W. But if Connor is right, the climate change we have already seen is a consequence of only about 1 W net forcing implying that most of the greenhouse warming is still hidden by aerosols.

39 The United Nations Framework Convention on Climate Change Aim to stabilize greenhouse gas emissions- at a level that would prevent dangerous anthropogenic interference with the climate system.

40 Metrics for Dangerous Change Extermination of Animal & Plant Species 1. Extinction of Polar and Alpine Species 2. Unsustainable Migration Rates Ice Sheet Disintegration: Global Sea Level 1. Long-Term Change from Paleoclimate Data 2. Ice Sheet Response Time Regional Climate Disruptions 1. Increase of Extreme Events 2. Shifting Zones/Freshwater Shortages

41 Tipping Point Definitions 1. Tipping Level - Climate forcing (greenhouse gas amount) reaches a point such that no additional forcing is required for large climate change and impacts

42 Tipping Point Definitions 2. Point of No Return - Climate system reaches a point with unstoppable irreversible climate impacts (irreversible on a practical time scale) Example: disintegration of large ice sheet

43 Phenomenon Assessment of Target CO 2 Target CO 2 (ppm) 1. Arctic Sea Ice Ice Sheets/Sea Level Shifting Climatic Zones Alpine Water Supplies Avoid Ocean Acidification Initial Target CO 2 = 350* ppm *assumes CH 4, O 3, Black Soot decrease

44 Initial Target CO 2 : 350 ppm Technically Feasible (but not if business-as-usual continues) Quick Coal Phase-Out Critical (long lifetime of atmospheric CO 2 ) (must halt construction of any new coal plants that do not capture & store CO 2 )

45 Free Will Alternative 1. Phase Out Coal CO 2 Emissions - by 2025/2030 developed/developing countries 2. Rising Carbon Price - discourages unconventional fossil fuels & extraction of every last drop of oil (Arctic, etc.) 3. Soil & Biosphere CO 2 Sequestration - improved farming & forestry practices 4. Reduce non-co 2 Forcings - reduce CH 4, O 3, trace gases, black soot

46 The Challenge We can avoid destroying creation! (+cleaner planet, + good jobs!) We have to figure out how to live without fossil fuels someday Why not now?

47 Intergenerational Conflict Intergenerational inequity and injustice is the result, affecting the young and unborn. Did not know defense of prior generations no longer viable. Ethical and legal liability questions raised by actions that deceived the public. Continued failure of political process (not even available to young and unborn) may cause increasing public protests.

48 Jake 11 months Jake is our newest grandchild, my son s first child. Jake has not done much of anything to cause global warming. He doesn t even walk yet. He crawls fast. My parents lived about 90 years, so Jake will probably be around most of this century. He will live in the greenhouse world that we choose to create.

49 My 4 month-old grandson Kai and his parents

50 Jim Hansen Web Site includes Target Atmospheric CO 2 : Where Should Humanity Aim? Global Warming Twenty Years Later: Tipping Points Near

51 Science in the Policy Arena Science is an increasingly important factor in decisions the government makes about health, security, and sustainability Science is only one aspect of the policy process, but it must remain an independent one Manipulation or suppression of science before it enters the public policy arena is not politics as usual and is not OK Union of Concerned Scientists (UCS) 2006

52 Interference in Climate Research There exists, and has existed since the 1990s, an overwhelming consensus among scientists that the planet is warming, and that humans heat-trapping emissions are the primary cause of this change In the United States, political interference in climate change science has contributed to the appearance of ongoing debate about the causes Union of Concerned Scientists (UCS) 2006

53 Consequences: Climate Research As a result: The public is widely misinformed about the existence of scientific consensus We fail to protect future generations and our planet from the consequences of global warming Policy makers cannot make fully informed decisions Federal agencies are unable to fulfill their scientific missions Union of Concerned Scientists (UCS) 2006

54 Solutions and Reforms The government should develop policies that will ensure: Openness Transparency Accountability Prevention Union of Concerned Scientists (UCS) 2006

55 Solutions and Reforms Reframing the problem Science has been called on to do something beyond its purview: not just improve people s understanding of the world, but compel people to act in a particular way. For nearly twenty years, researchers, policy-makers and activists have claimed that climate science requires a global policy agenda of top-down, United-Nations-sponsored international agreements; targets and timetables for emissions reductions; and the creation of carbon markets. But this agenda was guaranteed to be politically divisive because it entails short-term political and economic costs in return for benefits that are long term and highly uncertain. Daniel Sarewitz, co-director of the Consortium for Science, Policy and Outcomes, Arizona State University March 3, 2010 Nature

56 Solutions and Reforms A successful climate policy regime will match short-term costs with the real potential of short-term gains. These gains can come from reducing vulnerabilities to climate impacts, and increasing security and wealth generation from energy-technology innovation. Both paths call on the government to do things that most people see as appropriate: to provide public goods and promote innovation. Both paths also allow climate change to be understood not as impending doom that requires deep sacrifice to ensure survival, but as an opportunity to continually improve society. Daniel Sarewitz, co-director of the Consortium for Science, Policy and Outcomes, Arizona State University March 3, 2010 Nature

57 Solutions and Reforms The recent negotiations in Copenhagen might have gone better had the justification been framed in terms of conserving the world's dwindling oil reserves, stabilizing oil prices and promoting energy independence. The current stalemate is likely to persist as long as scientists allow climate change to dominate the environmental policy agenda. In order to promote a more productive dialogue between scientists and policymakers, the discussion of adaptation and mitigation options in the policy arena needs to be reframed so that it addresses environmental degradation and sustainability in the broad sense, not just the impacts of climate change. March 26, Seattle Times - op ed piece by John Wallace, professor and former chairman of the Department of Atmospheric Sciences at the University of Washington

58 Solutions and Reforms If we look beyond waging ideological battles through science we just might make better progress on reducing vulnerabilities and increasing security and wealth. Those are goals that we all can agree on, regardless of our views on climate science or political orientation, and can offer a starting point for progress.