http://www.debate.org...... ... 1....
Climate Change Is Not an Imminent Danger
http://www.youtube.com... (For reasons that I cannot determine, the picture embed function continues not to work. My apologies.) I.A. The Sun: Well, I have no argument with saying that the Sun is the main factor on climate. Without it we'd be freezing--below freezing, in fact. But that doesn't necessarily mean that it's the main factor causing climate change. Since the Sun is, indeed, emitting less energy compared to what it used to, we're left with the question of why the globe is still warming (I'll get to his argument, the 1500 year cycle, later). The Sun's contribution to the temperature trend since the late 1980s is, actually, negative. Lockwood said in his 2008 paper "Recent changes in solar outputs and the global mean surface temperature" that the best esitmate is -1.3% of the temperature rise, with uncertainty placing it in the range of -.7% to -1.9%[1]. Clearly the Sun can't be invoked to explain recent temperature rises, since it should be causing us to cool. Further evidence that it isn't the Sun can be found in the fact that the equation http://www.debate.org...... where, to quote Lockwood: "S is the solar input variation; V is the volcanic aerosal effect (quantified by the global mean atmospheric optical depth, AOD); ΔE is the anomaly of energy exchange between the deep ocean and the surface mixing layer (Willis et al. 2004), here quantified by the N3.4 ENSO index; L is a linear drift term to allow for anthropogenic grenhouse gas and aerosol emissions (and associated feedbacks); and kE, kV and kS are the appropriate weighting (sensitivity factors)." In plain English, that means that the equation is the result of what we think we know about how climate works, and was derived basically by combining a bunch of factors (including how sensitive we think the climate is to carbon dioxide/greenhouse gases--this is important) and seeing how we think that'll affect the climate. And as we see from the below graphic, it's not a bad prediction. http://www.debate.org...... Recently, the predicted values are actually too low, which basically means that if anything we're current underestimating climatic sensitivity, or have missed a factor influencing climate.[1] Observed is blue, predicted is red. Now, it is theoretically possible that the equation could still be completely wrong, and it just happened to fit well. But I regard it as a very small possibility. Certainly claiming that it is just a coincidence strains credulity. I.A.1. Solar Flux Predictions Pro is mistaken: The solar irradiation we are receiving has been declining for significantly longer. In fact, it has been decreasing since the 1980s, and would have been decreasing from the 1960s if not for a much larger drop that lasted a very short period of time. See below: http://www.debate.org...... I.A.2. Cosmic Ray Flux Cosmic rays induce aerosols, of that I have no doubt. But that does not necessarily lead to an increase in cloud cover, at least not a noticeable increase. There are various barriers to forming a cloud if one is a cosmic ray[2]. Mathematical models, meanwhile, put cosmic ray flux at two orders of magnitude too small to cause the observed cloud cover variation[3]. I.A.3. Ocean Currents Ocean currents can't heat themselves, though. They can only shift heat around. The ocean itself is heating[4]: http://www.debate.org...... I.B. The 1500-Year Cycle The 1500 year cycle my opponent refers to is, rather than an example of the globe increasing in temperature, an example of a bipolar see-saw, with the amount of heat remaining relatively constant but flowing to different places. My video explains this in more detail; increases in the North are offset by decreases in the South[5]. In climatology, these are called Dansgaard-Oeschger events[6]. Redistribution of heat is radically different than an increase in heat. The term "global warming" indicates that, rather than heat flowing, the entire planet is warming--this is based up by graphs of total heat content[4]. II. Positive Effects of the Current Interglacial and Warm Period II.A. Health Effects I would simply like to reiterate that extreme heat does not behave the same as extreme cold. The predicted increase in deaths due to heat wave is approximately four times larger than the decrease in deaths due to cold snap[7]. The reason is simple: Easier to make fire than an air-conditioner. Similarly, there is an upper limit to heat adaptability: Beyond about 35 degrees humans will start to experience the effects of hyperthermia, since we won't be able to dissipate heat[8]. An increase in seven degrees would cause large areas to experience this heat stress. This is about as the most reasonable value for the predicted temperature increase[9]. II.B. Economic Benefits Plants that have more carbon dioxide and are experiencing more growth because of it also need more water to sustain that growth[10]. They are also more vulnerable to pests[11], and plants such as wheat can become less nutritous[12]. 1. http://rspa.royalsocietypublishing.org...... 2. http://www.atmos-chem-phys-discuss.net...... 3. http://www.leif.org...... 4. http://www.agu.org...... 5. see video 6. http://en.wikipedia.org...... 7. http://oem.bmj.com...... 8. http://www.pnas.org...... 9. http://www.skepticalscience.com...... 10. http://www.skepticalscience.com...... 11. http://www.sciencedaily.com...... 12. http://www.sciencemag.org......