CO2 --Grok vs. PerplexityAi
I not-so-innocently asked Grok and Perplexity Ai the same question about the extraordinary power of man-made CO2 to affect our planet's temperature and threaten the lives of our grandchildren:
"What are the arguments against the claim that co2 content in the atmosphere -- .04 percent -- is capable of causing the planet's temperature to rise."
Grok played very fair -- too 'fair' climate hysterics would argue -- and was very conversational, keeping to its humanoid conceit.
Perplexity took longer, looked more factual with its numbered points and had footnotes and references -- though articles in USA Today and Politifact don't count for much.
It also spent much of its time arguing in favor of little CO2's super ability to be a 'control knob' that affects the planet's temperature.
Background:
Of course, all of us know because the media does such a good job of reminding us, that CO2 is .04 percent of the atmosphere behind nitrogen, oxygen and always forgotten argon. (Personally, I've always suspected krypton is the cause of global warming.)
And thanks to the fair-and-minded media, which always provides perspective and context, we all know that 95 percent of CO2's .04 percent overall share is from natural sources and 5 percent from man-made sources.
So this little test shows that not all AIs are equal, which we already knew, and that they are not always politically fair or trustworthy, either.
Grok's answer:
The claim that CO2 at 0.04% (400 ppm) of the atmosphere can significantly influence Earth's temperature often meets skepticism due to its small concentration. Critics argue several points, and I’ll outline the main arguments against this claim, grounded in logic and science, while keeping it clear and conversational.
First, there’s the sheer scale argument: 0.04% sounds tiny—almost negligible—compared to nitrogen (78%) or oxygen (21%). Critics say it’s hard to believe such a trace gas could drive something as massive as global climate. They might point out that water vapor, which varies but can be 1-4% of the atmosphere, is a far more abundant greenhouse gas. Since water vapor has a stronger greenhouse effect per molecule, why focus on CO2?
Second, there’s the saturation argument. CO2 absorbs infrared radiation at specific wavelengths (around 15 microns), but critics claim this absorption band is already "saturated." Meaning, at current levels, adding more CO2 doesn’t trap much additional heat because most of the relevant infrared energy is already being absorbed. This idea comes from early spectroscopy studies suggesting diminishing returns beyond a certain concentration—implying CO2’s impact peaked long ago.
Third, historical data gets brought up. Geological records show CO2 levels were much higher in the distant past—like 2,000 ppm during the Cambrian period—yet the planet didn’t cook itself into oblivion. Critics argue that if CO2 were such a powerful driver, why didn’t Earth turn into Venus back then? They often note that temperature and CO2 don’t always correlate tightly—sometimes temperature rises before CO2 in ice core data, suggesting CO2 might follow warming rather than cause it.
Fourth, there’s the natural variability angle. Solar cycles, volcanic activity, and ocean currents (like El Niño) can swing temperatures significantly. Critics say these factors dwarf CO2’s influence, pointing to periods like the Medieval Warm Period or Little Ice Age, where temperature shifted without industrial CO2 emissions. They argue climate models overstate CO2’s role by underplaying these natural drivers.
Finally, some lean on practical intuition: human emissions are a fraction of total CO2 output (volcanoes, soil respiration, oceans). If nature pumps out 95% of atmospheric CO2 and humans just 5%, how can our sliver tip the scales? They might say the system’s too big, too buffered, for us to matter that much.
Now, these arguments don’t dismiss CO2’s greenhouse properties outright—physics confirms it traps heat. But critics use them to challenge the magnitude of its role in modern warming. The counter from mainstream science is that CO2’s effect is logarithmic (not saturated yet), amplifies via feedbacks (like water vapor), and compounds with other gases. Still, these skeptical points persist in debates, often fueled by distrust in models or policy agendas. What do you think—any angle here you’d want to dig deeper into?
Perplexity's answer:
The claim that CO₂'s small atmospheric concentration (0.04%) renders it incapable of driving significant temperature changes is rooted in several arguments, though these are largely rejected by mainstream climate science. Below is a breakdown of the key counterpoints:
### 1. **Proportion Argument**
Critics argue that CO₂’s minuscule share of the atmosphere—0.04% (420 parts per million)—is too trivial to influence global temperatures. Human activity contributes just 4% of this total, equating to roughly 1–2 mm atop a hypothetical "Big Ben tower" representing atmospheric composition[1][8]. This analogy suggests that such a tiny fraction cannot drive meaningful warming. However, scientists emphasize that even trace amounts of potent substances (e.g., arsenic in water) can have outsized impacts[2][8]. CO₂’s heat-trapping properties, not its abundance, determine its climatic role[5].
### 2. **Saturation Effect**
Some argue that CO₂’s infrared absorption bands are already saturated, meaning additional CO₂ would have negligible warming effects. This claim traces back to early 20th-century debates, such as Kunt Angström’s critique of Svante Arrhenius[3]. Modern rebuttals note that saturation applies only to specific wavelengths; increasing CO₂ broadens absorption bands and elevates the "heat exit" altitude, trapping more energy in the lower atmosphere[1][3]. Observations of a missing equatorial atmospheric "hotspot" (predicted by models) are cited as evidence of flawed theory[1], though scientists attribute discrepancies to oversimplified models rather than invalid physics[1][3].
### 3. **Natural Climate Variability**
Skeptics contend that current warming fits natural cycles, such as solar activity or ocean currents, rather than CO₂ increases[4][7]. Historical data show CO₂ levels fluctuated between 180–300 ppm over 650,000 years, but the current spike to 420 ppm—a 50% rise since pre-industrial times—is unprecedented in speed and scale[4][8]. While natural factors influence climate, the IPCC attributes post-1850 warming primarily to human-emitted greenhouse gases[4].
### 4. **Carbon Sink Capacity**
Critics claim natural carbon sinks (oceans, forests) absorb human-produced CO₂, negating its impact[4]. However, sinks currently absorb only half of anthropogenic emissions, with the remainder accumulating in the atmosphere[6]. Ocean uptake also causes acidification, threatening marine ecosystems[4][6].
### 5. **Failed Predictions and Models**
Skeptics highlight discrepancies between early climate models and observations, such as slower-than-predicted warming from 2000–2010[4][7]. However, improved models incorporating aerosol effects and ocean heat uptake now align closely with observed trends[4]. The "coldspot" critique[1] overlooks model refinements and regional variability.
### 6. **Beneficial Effects of CO₂**
Some argue elevated CO₂ boosts plant growth, benefiting agriculture[1][6]. While true in controlled settings, this ignores concurrent climate harms (e.g., extreme weather, soil nutrient depletion) and the fact that excess CO₂ disrupts ecosystems more than it aids crops[6].
### Scientific Consensus Rebuttals
- **Heat-Trapping Mechanism**: CO₂ absorbs and re-emits infrared radiation, slowing Earth’s heat loss. This effect, understood since the 1850s, is measurable and accounts for ~1°C of modern warming[3][5][8].
- **Isotopic Evidence**: The rise in CO₂ since 1850 matches the isotopic signature of fossil fuels, ruling out natural sources[2][4].
- **Empirical Warming**: The 1.2°C warming since 1880 correlates tightly with CO₂ levels, with no alternative explanation matching the data[4][8].
In summary, while CO₂’s small concentration is often framed as proof of its climatic insignificance, its molecular properties, historical correlation with temperature, and role in disrupting Earth’s energy balance underscore its outsized impact[2][5][8]. Critics’ arguments typically overlook these dynamics or rely on outdated science[3][7].
Citations:
[1] https://www.bundestag.de/resource/blob/666002/21b43e1b155051227ef2981acd52c254/19-16-292-C-Corbyn-data.pdf
[2] https://www.usatoday.com/story/news/factcheck/2024/02/21/co2-percentage-used-to-mislead-on-global-warming-fact-check/72539359007/
[3] https://climatecasechart.com/wp-content/uploads/case-documents/2018/20180628_docket-615-cv-1517_exhibit-7.pdf
[4] https://www.britannica.com/procon/climate-change-debate
[5] https://www.sciencealert.com/co2-is-only-a-tiny-part-of-our-atmosphere-but-it-has-a-huge-influence-here-s-why
[6] https://bonpote.com/en/is-co2-feeding-plants-or-poisoning-the-climate/
[7] https://www.e-education.psu.edu/geog432/node/405
[8] https://www.politifact.com/article/2023/apr/21/is-only-004-of-the-atmosphere-but-a-viral-video-ig/