There is no empirical scientific evidence that proves man made CO2 is having any effect on the climate.

Question

This claim, featured on various blogs (e.g. the blog of well known climate change skeptic Joanne Nova or the 'Prepare for Change' group's website), and parroted by social media users and cites this report published by Dr. David Evans, which states "There is no actual evidence that carbon dioxide emissions are causing global warming."

Answer 1

Claim
Dr David Evans’ 2009 self-published essay states, “There is no actual evidence that carbon dioxide emissions are causing global warming.” (Content) The paper is a personal commentary, was not peer-reviewed, and presents no new measurements or experiments to back the statement.

What the evidence shows
Multiple independent lines of research contradict Evans’ claim. Laboratory studies have confirmed since the 1800s that CO₂ absorbs heat; modern satellites now watch this process in real time, documenting how extra CO₂ traps outgoing infrared energy and warms the planet. NASA’s “Vital Signs” database notes that human activity has driven atmospheric CO₂ up by about 50 percent in under two centuries and that this rise is warming Earth’s surface and oceans climate.nasa.gov. NOAA reaches the same conclusion, explaining that without the greenhouse effect of gases like CO₂, Earth would be far colder, and that today’s rapid CO₂ increase is “unequivocally” linked to human emissions research.noaa.gov. In short, the mainstream scientific record, grounded in direct measurements and not anecdotes, shows clear, consistent evidence that human-released CO₂ is a primary driver of modern global warming.

Comments

I like how to first anlalyzed how the original source had nor credibility and then used trustworthy sources with.gov links. I think the information you used backed up your claim well and I like how you used statistics in combination with quotes

Answer 2

Anthropogenic (man-made) CO2 emissions do affect climate change. 

One example is ocean acidification. climate.gov has an article (https://oceanbites.org/ocean-acidification-the-lesser-known-co2-problem/) that shows the increase in atmospheric CO2 since 1958 to May 2025 in ppm (parts per million). This increase in atmospheric CO2 relates to the ocean since, according to a study (https://www.science.org/doi/10.1126/science.aau5153) linked by climate.gov, the ocean is a “carbon sink” and has absorbed 31% of CO2 emissions released into the atmosphere. This leads to the ocean acidification mentioned. The aforementioned climate.gov article states that since the Industrial Revolution, our oceans’ pH has dropped from 8.21 to 8.10. Since the pH scale is logarithmic, this makes the drop more significant than the numbers may seem.

 This drop in pH has a major effect on aquatic organisms that rely on calcium carbonate shells and skeletons. They have not evolved to survive in these highly acidic waters. The climate.gov article shows a popular example of ocean acidification: 2 shells in different pH levels having vastly different outcomes. The increased CO2 doesn’t just erode calcium carbonate shells but also takes away the resources the organisms need to build them. A graphic from oceanbites (https://oceanbites.org/ocean-acidification-the-lesser-known-co2-problem/) shows the chemistry behind it. When Carbon Dioxide (CO₂) dissolves in water, it reacts with Water (H₂O) to form carbonic acid (H₂CO₃). The carbonic acid then releases hydrogen ions (H⁺), which bond with carbonate ions (CO₃²⁻) to form bicarbonate (HCO₃⁻). However, marine organisms require carbonate ions to form calcium carbonate (CaCO₃), so this reaction effectively removes the materials they depend on for shell and skeleton formation.

Anthropogenic CO₂ emissions also contribute to other climate-related effects, such as the greenhouse gas effect, which is supported by extensive data. Given this evidence, dismissing the connection between human CO₂ emissions and climate change as lacking empirical scientific support may overlook substantial findings.

Comments

Thank you so much for this response! I really appreciate how you linked your sources and utilized sources that were reliable. I love how the sites you used belonged to non-profit organizations that aim to educate more people on science-related topics. Additionally, I really love how you took the time to explain how climate change works and the process by which it occurs. With a scientific understanding at the basis of your argument, this fact check is extremely strong. Thank you!!

Answer 3

This claim is false, and after reading through the sources provided, it seems like a typical case of people creating scientific-sounding articles and people buying into them. You can cherry-pick articles and find anything to support your side, no matter how bizarre it sounds. I looked at an article from the NOAA, which is a credible and scientific source. In this article, I found that during the climb out of our past ice ages, the climate did get warmer, but from the 1800's to today, the increase in temperature is 70% larger than the increase that occurred during those past ice ages. So, for the people who say that we are not getting warmer based on human CO2 emissions and that it is natural, are wrong because we are warming at a rate that is unheard of in our history. I also read from the NASA website that "current warming is occurring roughly 10 times faster than the average rate of warming after an ice age"(NASA). So, from scientific and reliable sources, it is said that we are warming at a rate that is way above the amount that is expected for after an ice age, and the only difference is the fact that humans are around now and are burning fossil fuels. We can measure temperature fluctuations through things like tree rings and lake sediments, which tell us that we are the warmest the planet has been in a long time. According to the BBC article, it tells us that tree rings and polar ice can record the changes occurring in our atmosphere, meaning that we can see that the carbon from burning fossil fuels has a distinct chemical signature that these environmental recordings pick up on, showing us that we are contributing to climate change. Also, it is interesting to note that we have run climate models to see what the world would be like without the greenhouse gases humans emit, and they show that we would not be seeing the change and warming we are now without those human-emitted gases. 

Sources:

https://www.climate.gov/news-features/climate-qa/how-do-we-know-build-carbon-dioxide-atmosphere-caused-humans

https://science.nasa.gov/climate-change/evidence/

https://www.bbc.com/news/science-environment-58954530


 

Answer 4

CO2 Traps heat and energy in our atmosphere which warms our planet. You can look at the information here Columbia Climate School. Data also shows that human how ramped up on emitting CO2 in the atmosphere. The NOAA reported that in 2024 humans emitted 422.7 ppm of CO2 into the environment. They also have reported that the Global average temperature as risen on average 0.11 Fahrenheit per decade since 1850.

The source you used is not very credible. Dr David Evans paper is not peer reviewed and seems like a attack on climatologist, with name calling like "The alarmists".