Are humans the main cause of global warming?

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Global warming (or climate change or global heating) poses a very real threat to the world's ecosystem and to human life. Some doubt its existence and others that human activity is responsible for global increases in temperature and related weather phenomena. This debate takes it for granted that global warming exists but asks to what extent humans create or hasten those conditions.

Humans are the main cause of global warming[edit | edit source]

Arguments for[edit | edit source]

  • Argument for — Almost all—roughly 97%—earth scientist believe that global warming is real, has been occurring throughout the 20th and 21st centuries, and has a substantial man-made component.[1][2][3]
    • Objection — This is an argument from authority.
      • Objection — Yes, it's an argument from authority, but that doesn't change the fact that ~97% of experts agree. The argument should remain "sustained" and each reader will judge its weight.
      • Objection — Fallacious arguments from authority rely on someone propounding outside his field of expertise whereas climate scientists are by definition experts on climate.
        • Objection — That is only one kind of argument from authority. Experts have been wrong many many times in the past. Experts must prove their contentions like everybody else.
          • Objection — The fact that others have been wrong about other things is a fallacious line of reasoning itself.
          • Objection — Climate scientists experts do prove their assertions with their work. That's how the scientific community reaches a consensus in the first place.
            • Objection — Only mathematicians "prove" their assertions. If empirical scientists proved their assertions, they wouldn't have been wrong before. Empirical scientists can only provide strong arguments for their conclusions, but they can always be wrong, as so many of them have been before. Thus citing their authority is not enough. Their actual arguments must be provided.
            • Objection — Then post their actual arguments and evidence, rather than defending an argument that doesn't include them.
              • Objection — They are cited above.
                • Objection — That's lazy, better is to bring them to the wiki so we can debate them (and trim this branch of the debate).
    • Objection — 99.9% of bishops agree there is a God. This does not necessarily make it true—especially when funding requires following a creed. The global temperature has been increasing and variable for many thousand of years. The argument should be about whether change has become more rapid and how much of that is attributable to humans.
      • Objection — Widespread agreement certainly doesn't make anything wrong either. Scientists use a method which is verifiable so you can check their science yourself or create new experiments with new explanatory methods. Just nay-saying science as a field is hardly an argument. If someone could disprove human responsibility for global warming, that person would get a virtually limitless amount of funding: conservative science which just proves what we already know is not attractive to grantors. The consensus precisely is that human activity plays a non-negligible role in climate change.
        • Objection — The point is the number of believers or disbelievers is moot. Ether had a strong belief amongst scientists who were experts. The other point is to show the argument is much more nuanced. Given that other massive rises in global temperature have not eliminated life it is difficult to read hysterical statements and believe them. The argument needs to be more nuanced as the bold fear mongering that accepts no critique (critique is a staple of scientific discourse) only helps people state this is a hoax.
          • Objection — This is not even an argument: saying that it can't be true because it's not nuanced enough? What is your point?

Arguments against[edit | edit source]

  • Argument against — The science shows that climate change is happening but not that it's influenced by human activity.[citation needed]
    • Objection — That is actually the opposite of what the science says: virtually all climate scientists agree that human activity is accelerating any natural process of global warming.[1][2]
      • Objection — That is not entirely accurate. The science is often using abductive reasoning and is also using "post hoc, ergo propter hoc" arguments by looking at correlations and extrapolating. Much is overstated and used to back up one political narrative whereas looking at actual data suggests a more complex argument is needed. For instance roughly 60% of the greenhouse effect is caused by natural water vapor (i.e. clouds) not CO2. CO2 has lots of origins, for instance every animal on Earth exhales CO2. Methane is often also discussed. It is true Methane, pound for pound, is 25× more potent than CO2 as a greenhouse gas however the concentration is 1/200th that of CO2 in the atmosphere so its contribution is effectively negligible—especially as it also comes from natural sources such as the wetlands we keep preserving so not all of it can be prevented. The yearly human addition to CO2 that occurs naturally is less than 4%.[citation needed] It is true that only part of this addition gets absorbed again and hence the effect is incremental but we also need to acknowledge natural processes have a habit of correcting themselves such as high CO2 encourages more growth of carbon sinks. As Earth's custodians, and residents, we should curtail pollution and limit our contribution to global warming, if that is possible, but we should also reflect it is a long term natural and nuanced process if we are to be believed, because a hint of dishonesty sinks the argument. Hysterical statements that we are all doomed simply add to eye rolling from disbelievers as history has shown significant temperature changes without extinguishing life. Rhetoric has overtaken accuracy.
        • Objection — "Looking at correlations and extrapolating" is a key element of science and it's not abduction but induction: one of the pillars of the scientific method.[4]If humans have such a small impact on global warming, then why would we curb our pollution? The argument that overstatements may embolden the opposition is also irrelevant if no one is overstating them: which statements are inaccurate?
  • Argument against — The most extensive melting of polar ice caps occurred in 2005. The second most extensive melting of polar ice caps occurred in 2016.[citation needed] The sunspot cycle, the major one, has a period of 11.2 years. This suggests that humans are a secondary cause, not the primary one.

See also[edit | edit source]

Notes and references[edit | edit source]

  1. 1.0 1.1 "CLIMATE CHANGE 2014: Synthesis Report. Summary for Policymakers" (PDF). IPCC. Retrieved 1 November 2015. The following terms have been used to indicate the assessed likelihood of an outcome or a result: virtually certain 99–100% probability, very likely 90–100%, likely 66–100%, about as likely as not 33–66%, unlikely 0–33%, very unlikely 0–10%, exceptionally unlikely 0–1%. Additional terms (extremely likely: 95–100%, more likely than not >50–100%, more unlikely than likely 0–<50% and extremely unlikely 0–5%) may also be used when appropriate.
  2. 2.0 2.1 "CLIMATE CHANGE 2014: Synthesis Report. Summary for Policymakers" (PDF). IPCC. Retrieved 7 March 2015. The evidence for human influence on the climate system has grown since the Fourth Assessment Report (AR4). It is extremely likely that more than half of the observed increase in global average surface temperature from 1951 to 2010 was caused by the anthropogenic increase in greenhouse gas concentrations and other anthropogenic forcings together
  3. {{Cite book | publisher=The National Academies Press | isbn = 0-309-14588-0 | last = America's Climate Choices: Panel on Advancing the Science of Climate Change; National Research Council | title = Advancing the Science of Climate Change | location = Washington, D.C. | year = 2010 | url = | quote = (p1) ... there is a strong, credible body of evidence, based on multiple lines of research, documenting that climate is changing and that these changes are in large part caused by human activities. While much remains to be learned, the core phenomenon, scientific questions, and hypotheses have been examined thoroughly and have stood firm in the face of serious scientific debate and careful evaluation of alternative explanations. ***(p21-22) Some scientific conclusions or theories have been so thoroughly examined and tested, and supported by so many independent observations and results, that their likelihood of subsequently being found to be wrong is vanishingly small. Such conclusions and theories are then regarded as settled facts. This is the case for the conclusions that the Earth system is warming and that much of this warming is very likely due to human activities.
  4. Andersen, Hannah; Hepburn, Brian (2015-11-13). "Scientific Method". Stanford Encyclopedia of Philosophy. Among the activities often identified as characteristic of science are systematic observation and experimentation, inductive and deductive reasoning, and the formation and testing of hypotheses and theories.