# What percentage of scientists actually support anthropogenic global warming? **URL:** \ **Category:** Factual Questions\ **Created:** [September 19, 2018, 7:00pm UTC](https://boards.straightdope.com/t/what-percentage-of-scientists-actually-support-anthropogenic-global-warming/821594 "2018-09-19T19:00:40Z")\ **Posts on this page:** 10\ **Page:** 4
**Author:** ![wolfpup](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wolfpup/32/10618_2.png) [@wolfpup](https://boards.straightdope.com/u/wolfpup)\ **Post date:** [September 24, 2018, 5:04pm UTC](https://boards.straightdope.com/t/what-percentage-of-scientists-actually-support-anthropogenic-global-warming/821594/61 "2018-09-24T17:04:12Z")
> [@md2000](#): > > As I said - there’s only one way to find out, and we’re about to find out. The real question is - how bad will it be? What will be the final climate patterns? Will excess heat result in excess cloud cover (cyclic negative feedback) and massive rainfalls, regular flooding? Or will the result be positive feed back and a desert world? > > All the educated guesses in the world are just that - guesses. We have no idea what exactly will happen except that it’s a good bet things will be severely disrupted one way or another. There are a lot of incorrect assumptions there. The impacts of climate change do indeed contain many unknowns, but the major impacts are established well beyond “guesses” – see for instance the current [IPCC WG2 assessment on _Impacts, Adaptation, and Vulnerability_](http://www.ipcc.ch/report/ar5/wg2/). Most importantly, regardless of specific details like regional climate changes in specific areas and the precise patterns of extreme weather, there is absolutely zero evidence that any magical process is going to intervene to prevent the problems from getting steadily worse, including all the things we’re already seeing – sea level rise, stronger storm surges, ocean acidification, polar ice loss and thus Arctic temperature amplification, heat waves, persistent weather changes, etc. Hence the international impetus to sign agreements like the Paris climate accord of 2016. The cloud cover argument is a red herring, first because there’s no evidence for it, and second because clouds are both positive and negative feedbacks depending on their type and altitude, because some high-altitude clouds are more effective at blocking outgoing IR than incoming sunlight and so are actually positive feedbacks. As for desertification, that doesn’t require positive feedback. On balance, the emerging picture of climate change is permanent regional changes with desertification in some areas but generally increased global precipitation that manifests in many areas, producing flooding, stronger storms, and assorted risks to food crops. The fact is that there are many sources for climate predictions from the earth’s climate history (paleoclimate studies) and increasingly from global climate models and contemporary observations. Climate feedbacks are overwhelmingly positive and some, like Arctic ice loss, are accelerating. We can also see the impacts of specific events like the [Paleocene-Eocene Thermal Maximum](https://en.wikipedia.org/wiki/Paleocene%E2%80%93Eocene_Thermal_Maximum) 55 million years ago, which parallels present AGW in that it was caused by the injection of massive amounts of carbon into the atmosphere over a relatively short period (probably from undersea biomass). The global temperature shot up between 5 and 8°C with no magical negative feedbacks to stop it, and caused devastation to the oceans, to major global ocean circulation systems, and to life on land. Such a rise in global average temperature today would be absolutely catastrophic. The fact is that the most important unknown in climate projections is the extent to which we have the political will and technological capability to limit carbon emissions as much as is required. That’s why the IPCC discusses future climate in terms of models that assume a specific level of climate forcing from man-made GHGs at a given point in time. That’s the biggest variable and the biggest unknown of all. ---
**Author:** ![am77494](https://avatars.discourse-cdn.com/v4/letter/a/d2c977/32.png) [@am77494](https://boards.straightdope.com/u/am77494)\ **Post date:** [September 24, 2018, 5:36pm UTC](https://boards.straightdope.com/t/what-percentage-of-scientists-actually-support-anthropogenic-global-warming/821594/62 "2018-09-24T17:36:24Z")
> [@wolfpup](#): > > The fact is that the most important unknown in climate projections is the extent to which we have the political will and technological capability to limit carbon emissions as much as is required. That’s an opinion disguised as a fact. Global dimming i.e. the use of aerosols / particulates to limit sunlight reaching the earth is another option that maybe used in combination with carbon emissions reduction or as a stand-alone technology. IIRC, the reduction of sunlight reaching earth needs to be reduced only 1% to negate global warming. As I understand, these aerosols / particulates are currently under research. ---
**Author:** ![Sailboat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sailboat/32/461_2.png) [@Sailboat](https://boards.straightdope.com/u/Sailboat)\ **Post date:** [September 24, 2018, 5:43pm UTC](https://boards.straightdope.com/t/what-percentage-of-scientists-actually-support-anthropogenic-global-warming/821594/63 "2018-09-24T17:43:58Z")
> [@Chronos](#): > > There are almost no reasons to buy organic foods. There are reasons to buy sustainable foods, or small-batch foods, or cruelty-free foods, or heirloom foods, or many other categories. But despite what many people think, those categories have only incidental overlap with “organic”. This is a hijack, but pesticide bioaccumulation is one reason. ---
**Author:** ![GIGObuster](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gigobuster/32/421_2.png) [@GIGObuster](https://boards.straightdope.com/u/GIGObuster)\ **Post date:** [September 24, 2018, 6:09pm UTC](https://boards.straightdope.com/t/what-percentage-of-scientists-actually-support-anthropogenic-global-warming/821594/64 "2018-09-24T18:09:18Z")
> [@am77494](#): > > That’s an opinion disguised as a fact. Global dimming i.e. the use of aerosols / particulates to limit sunlight reaching the earth is another option that maybe used in combination with carbon emissions reduction or as a stand-alone technology. IIRC, the reduction of sunlight reaching earth needs to be reduced only 1% to negate global warming. > > As I understand, these aerosols / particulates are currently under research. Problem is that there is almost a universal aversion from contrarian sources to disparage computer modeling and paleo climate (just check how Mann was disparaged in this thread). Until they do drop their unreasonable opposition, that position leads to less money for research about how we can use dimming properly, not to mention the typical contradictory nature of the contrarians of today that would have to depend on the same scientists that they are disparaging now when considering geo engineering solutions. ---
**Author:** ![wolfpup](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wolfpup/32/10618_2.png) [@wolfpup](https://boards.straightdope.com/u/wolfpup)\ **Post date:** [September 24, 2018, 6:38pm UTC](https://boards.straightdope.com/t/what-percentage-of-scientists-actually-support-anthropogenic-global-warming/821594/65 "2018-09-24T18:38:32Z")
> [@am77494](#): > > That’s an opinion disguised as a fact. Global dimming i.e. the use of aerosols / particulates to limit sunlight reaching the earth is another option that maybe used in combination with carbon emissions reduction or as a stand-alone technology. IIRC, the reduction of sunlight reaching earth needs to be reduced only 1% to negate global warming. > > As I understand, these aerosols / particulates are currently under research. No, I have to say that it’s _ **your** _ statement here that is opinion disguised as fact. Look at the contents outline of the [latest IPCC WG3 report on mitigation](http://www.ipcc.ch/report/ar5/wg3/). Do you see anything there about “global dimming” or dumping crap into the atmosphere as a major discussion item? But, in truth, the IPCC has not ignored the general concept of what is variously called geoengineering or climate engineering, which are broad areas that include many different technologies of which the most feasible is carbon dioxide removal (CDR). They even had a special conference about it a few years ago. But all of these options are considered **last-ditch emergency measures** , strategies of last resort after all possible mitigation measures have been executed and proven inadequate. As stated in the SPM: _A risk management strategy for climate change will require integrating responses in mitigation with different time horizons, adaptation to an array of climate impacts, and even possible emergency responses such as ‘geoengineering’ in the face of extreme climate impacts_. Accordingly, geoengineering is mentioned in only three places in the entire lengthy WG3 report, and each time only briefly. And further, of all geoengineering strategies, dumping shit into the atmosphere is by far the most risky, most prone to undesirable and unexpected side effects, and most likely to be irreversible. And even if it works, it would have to be maintained indefinitely – regardless of what side effects emerge in the future – or we would face even more catastrophic climate consequences that would occur very suddenly. And there is evidence that, instead of working as expected, attempts to manage solar radiation through the atmosphere could make things even worse rather than better: Hegerl and Solomon (2009); Fleming (2010); Hamilton (2013). So the bottom line is: this kind of geoengineering is mostly fantasy, and its advocacy as a panacea is mostly crackpot madness. It poses extremely high risks and uncertainties, and does not in any way lessen the urgent need to meet emissions reduction targets and switch to clean energies. ---
**Author:** ![wolfpup](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wolfpup/32/10618_2.png) [@wolfpup](https://boards.straightdope.com/u/wolfpup)\ **Post date:** [September 24, 2018, 7:00pm UTC](https://boards.straightdope.com/t/what-percentage-of-scientists-actually-support-anthropogenic-global-warming/821594/66 "2018-09-24T19:00:58Z")
^^^ I should add to the above, my earlier point was that it’s a fact that where we end up by 2100 in terms of climate forcing is the biggest single uncertainty in climate projections, unless one wants to get into an argument about extremely unlikely fringe values of climate sensitivity. Hence [this very wide range](https://en.wikipedia.org/wiki/Representative_Concentration_Pathways) in what the IPCC calls Representative Concentration Pathways. In my view we’re likely to end up somewhere between RCP 6 (+6.0 W/m\*\*2 net climate forcing) and RCP 8.5, corresponding to a CO2 and CO2-equivalent concentration that may not be far off from my earlier comment about the possibility of 800 ppm by then. When you consider that in the last million years of this planet and all its ice ages the concentrations have varied in the narrow band between 180 and less than 300 ppm, representing the difference between an ice age maximum and the peak of interglacials, that should be pretty scary. ---
**Author:** ![am77494](https://avatars.discourse-cdn.com/v4/letter/a/d2c977/32.png) [@am77494](https://boards.straightdope.com/u/am77494)\ **Post date:** [September 24, 2018, 7:51pm UTC](https://boards.straightdope.com/t/what-percentage-of-scientists-actually-support-anthropogenic-global-warming/821594/67 "2018-09-24T19:51:10Z")
> [@wolfpup](#): > > No, I have to say that it’s _ **your** _ statement here that is opinion disguised as fact. Look at the contents outline of the [latest IPCC WG3 report on mitigation](http://www.ipcc.ch/report/ar5/wg3/). Do you see anything there about “global dimming” or dumping crap into the atmosphere as a major discussion item? > > But, in truth, the IPCC has not ignored the general concept of what is variously called geoengineering or climate engineering, which are broad areas that include many different technologies of which the most feasible is carbon dioxide removal (CDR). You presented as a fact that cutting back CO2 emissions was the only way to combat climate change. When challenged, you started with a personal insult, admitted that IPCC has considered other backup methods and then went on to rant for a long time. To me, you are no different than the Climate change deniers. With due deference, to me, you are no different than the climate change deniers. Maybe with more fanatism and sense of moral superiority. Meanwhile, me as a technologist worked on a Carbon Capture Plant about a decade back and our firm has a diversified portfolio on Global Dimming technologies too. Engineers solved the way out of SOx and NOx emissions and we will find a way out of CO2 emissions too. Feel free to carry on your grandstanding in the meantime. ---
**Author:** ![Kimstu](https://avatars.discourse-cdn.com/v4/letter/k/ecd19e/32.png) [@Kimstu](https://boards.straightdope.com/u/Kimstu)\ **Post date:** [September 24, 2018, 8:22pm UTC](https://boards.straightdope.com/t/what-percentage-of-scientists-actually-support-anthropogenic-global-warming/821594/68 "2018-09-24T20:22:27Z")
> [@am77494](#): > > To me, you are no different than the Climate change deniers. Sure. A knowledgeable science-aware person who criticizes some aspect of a highly hypothetical and complex proposed climate engineering system is literally **no different** from an irrational scientific ignoramus who outright rejects scientific findings. :rolleyes: ---
**Author:** ![Jackmannii](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jackmannii/32/311_2.png) [@Jackmannii](https://boards.straightdope.com/u/Jackmannii)\ **Post date:** [September 24, 2018, 8:33pm UTC](https://boards.straightdope.com/t/what-percentage-of-scientists-actually-support-anthropogenic-global-warming/821594/69 "2018-09-24T20:33:01Z")
> [@Chronos](#): > > There are almost no reasons to buy organic foods. There are reasons to buy sustainable foods, or small-batch foods, or cruelty-free foods, or heirloom foods, or many other categories. But despite what many people think, those categories have only incidental overlap with “organic”. > [@Sailboat](#): > > This is a hijack, but pesticide bioaccumulation is one reason. It may be a valid reason in some circumstances, but certainly not all. _“The sad truth is, factory farming is factory farming, whether it’s organic or conventional. Many large organic farms use pesticides liberally. They’re organic by certification, but you’d never know it if you saw their farming practices.”_ > **[Mythbusting 101: Organic Farming \> Conventional Agriculture](https://www.scientificamerican.com/blog/science-sushi/httpblogsscientificamericancomscience-sushi20110718mythbusting-101-organic-farming-conventional-agriculture/)** > **[Organic Pesticides: Not An Oxymoron](https://www.npr.org/sections/health-shots/2011/06/18/137249264/organic-pesticides-not-an-oxymoron)** > > A recently released report on pesticide residues found that about 20 percent of organic lettuce tested positive for pesticides. How could that be? We talked with the University of Minnesota's Jeff Gillman about the state of organic farming. > **[EU renews toxic pesticide amid safety uncertainty](https://www.euractiv.com/section/agriculture-food/news/eu-renews-toxic-pesticide-amid-safety-uncertainty/)** > > The European Commission and the member states extended once again the authorisation for copper sulphate, a controversial pesticide used in organic farming, which is on the EU’s “substitution” list and its effects on consumers are still unknown. ---
**Author:** ![wolfpup](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wolfpup/32/10618_2.png) [@wolfpup](https://boards.straightdope.com/u/wolfpup)\ **Post date:** [September 24, 2018, 8:41pm UTC](https://boards.straightdope.com/t/what-percentage-of-scientists-actually-support-anthropogenic-global-warming/821594/70 "2018-09-24T20:41:14Z")
> [@am77494](#): > > You presented as a fact that cutting back CO2 emissions was the only way to combat climate change. When challenged, you started with a personal insult, admitted that IPCC has considered other backup methods and then went on to rant for a long time. You accused me of having expressed a mere “opinion” regarding the fact that “the political will and technological capability to limit carbon emissions as much as is required” is the biggest unknown in assessing the future climate – apparently because you believe that “global dimming” will be a terrific solution to the problem. It was not an “insult” to say that the need to dramatically cut back on emissions is a fact, and that it is YOU who is expressing an opinion – and indeed a very fringe opinion – in bringing up your alternative proposed solution, and it’s unfortunate that you took it as an insult. It wasn’t meant as an insult and certainly not as a personal one, but when it comes to counterfactual bullshit I quite frankly call it as I see it, no offense intended. It’s amazing – and amusing – that you see my quotes from the IPCC report as being a “rant”. :rolleyes: Statements from the IPCC tend to be among the most scientifically conservative (in the sense of being measured and cautious) of any major organization in this arena. If you consider them a rant, that speaks volumes about your perspective on this issue, but perhaps I’m misreading your meaning. > [@am77494](#): > > Meanwhile, me as a technologist worked on a Carbon Capture Plant about a decade back and our firm has a diversified portfolio on Global Dimming technologies too. Engineers solved the way out of SOx and NOx emissions and we will find a way out of CO2 emissions too. There are a lot of issues with CDR (carbon capture) but at least it’s within the realm of reality as a potential auxiliary stopgap. “Global dimming” is extremely speculative, to say the least, and any suggestion that it’s the sole or primary solution while we continue to pollute the atmosphere with unprecedented levels of CO2 is, frankly, just madness. You don’t need to believe me. Read the IPCC WG3 report that I already linked to, each subject chapter produced by a panel of the world’s leading experts on the relevant issues. And your last sentence is frankly just bizarre. SOx and NOx emissions were solved by eliminating them, in part by technologies for reduction and scrubbing, and in part by conversions to cleaner fuels. This is essentially what we want to do with CO2 emissions, but it’s a lot more difficult since all fossil fuel combustion emits CO2 and large-scale capture just isn’t feasible. The irony of it is that the cleanup of those aerosols helped dramatically accelerate the otherwise suppressed greenhouse gas forcing in the latter half of the 20th century. We could always go back to pumping more SOx into the air, which was killing life in our lakes and rivers with acid rain and disintegrating our buildings. The mitigation of these aerosols was one of the most dramatic success stories in the history of the EPA and, indeed, in the history of emissions mitigation. It’s an object lesson that “global dimming” can have severe side effects. [Previous page](https://boards.straightdope.com/t/what-percentage-of-scientists-actually-support-anthropogenic-global-warming/821594.md?page=3)