Scientists Agree that Global Warming is happening and that we are the Cause

Super fact 34: Climate Scientists agree that Global Warming or if you call it Climate Change is happening, and that it is caused by us primarily because of our burning of fossil fuels. There is a long-standing scientific consensus on these two facts because the evidence is conclusive. Typically, studies show an agreement of at least 97% or 98% among climate scientists.

This is a super fact because surveys show that this is not what the public believes and yet it is true. The public incorrectly believes that there is a large disagreement among scientists on this topic. A note, to understand why the evidence is conclusive as to why global warming is happening and is caused by us click here.

Note : I will use the term “global warming” in this review. Whether you call the phenomenon climate change, climate disruption, or global heating, is not important.

The Scientific Consensus

This extensive survey from 2013 of 12,000 climate papers (papers published over two decades) by Dana Nuccitelli and Cook, etc., concluded that 97.1% of climate scientists endorsed the consensus position that humans are causing global warming.

They also did a science author self-rating which concluded that 97.2% of climate scientists endorsed the consensus position that humans are causing global warming. Another conclusion from the survey was that the consensus had increased from around 90%, perhaps less, in the early 1990’s.

A later review of six independent, peer-reviewed studies examining the scientific consensus about global warming have concluded that between 90% and 100% of climate scientists are convinced human-caused global warming is happening. A more recent study (2021) found that as many as 98% of climate scientists are convinced global warming is happening and is human-caused. Numerous other surveys have concluded the same thing.

People’s Beliefs About Global Warming

This 2024 survey from Yale University show that most Americans (61%) understand that global warming is mostly human caused. By contrast, 28% think it is caused mostly by natural changes in the environment. Most Americans (58%) <<Link-6>> understand that most scientists think global warming is happening. This percentage has trended generally upward since this survey began in 2008. By contrast, about one in five (22%) think there is a lot of disagreement among scientists about whether global warming is happening.

The green graph corresponds to “most scientists think global warming is happening (%).” The black graph corresponds to “there is a lot of disagreement among scientists (%)”. The yellow graph corresponds to “Most scientists think global warming is NOT happening (%)”. Graph taken from the Yale Program on Climate Change Communication.

However, only one in five Americans (20%) understand that nearly all climate scientists (more than 90%) think that human-caused global warming is happening. The aforementioned Dana  Nuccitelli refers to this in his book Climatology versus Pseudoscience as the consensus gap. Again, this large discrepancy between public perception and reality makes the consensus gap a super fact. Research has shown that this discrepancy has a large impact on people’s other beliefs regarding global warming.

The question was, To the best of your knowledge what percentage of climate scientists think that human-caused global warming is happening? Graph taken from the Yale Program on Climate Change Communication.

Why is there a Consensus Gap?

In his book Climatology versus Pseudoscience Dana Nuccitelli explains that a relatively small group of so-called climate skeptics, or more accurately called climate contrarians have received a lot of attention from media. Even though their science is bad, and they’ve published their error ridden papers in obscure or discredited journals, and the fact that their predictions have failed repeatedly many times over, they have had an enormous influence on public discourse. Conservative politicians, and many talk show hosts are blindly devoted to their falsehoods, whilst real scientists are being attacked.

It is not just rightwing media who are using them for their purposes, but mainstream media are giving the contrarians undue attention as well. Sensationalism is one issue. A science contrarian claiming that all the climate scientists are wrong, and that he is the only one who finally got it right is a lot more interesting of a story than a repeat of the consensus. Another issue is false balance. Journalist should not feel that they must give equal time to evidence-based science and nonsense, but that is often the case. To read my review of this book click here.

The Oregon Petition

I am mentioning the Oregon petition because I fell for it myself. The Oregon petition was an official looking petition circulated by climate contrarians, claiming that there is no evidence that human-caused global warming will cause catastrophic heating of earth’s atmosphere and disruption of earth’s climate, and that adding more carbon dioxide to the atmosphere would even be beneficial for plants and animals. It got an impressive number of signatures, 32,000 after some years.

However, it turned out that the signatories rarely had climate expertise, and were not scientists, and the survey listed many falsified names such as the names of the Spice Girls and several fictional characters. Less than 200 of the signatories were climate researchers.

It was a con, but it was touted in a lot of media as the truth. I saw it over and over and I believed it. I was later surprised to learn that it was a con and that a scientific consensus existed on global warming / climate change. Learning that I had been bamboozled on this matter was one of the red flags that prompted me to start doing some fact checking on the issue global warming.

To see the other Super Facts click here

Many Popular Environmental Actions Are Ineffective

Super fact 33: Actions such as eating locally, buying organic produce, using paper straws, and recycling can be good for the environment but can also be worse for the environment and these actions often have a much smaller positive impact than alternative rarely considered actions. What are popular actions for the environment is often different from what is effective.

I consider this a super fact because the beliefs regarding what is good for the environment and what is bad for the environment and what has a significant impact and what has not, are often based on popular trends and culture rather than knowledge. We need to educate ourselves. Following trends is not the answer to good stewardship of the planet.

This content was generated by an Artificial Intelligence (AI) system. Asset id: 2531547331

Is Locally Grown Food Really Better for the Environment?

As I explained in this post eating locally is not necessarily ecological. Agricultural products that are grown off season or in non-native environments are often grown in greenhouses, which require a lot of energy and generate significantly more emissions than shipping the produce across oceans would. This is especially true for crops like tomatoes, cucumbers, mangoes and bananas, that require warmer climates to be grown in open fields.

From pexels.com by Julia Nagy.

In some cases, the crop requires significant water resources or chemical inputs to thrive and may not be suitable for warmer climates, for example, apples. Some crops, like avocados or almonds require a lot of water but despite that they are grown in dry places like California (80% of California’s freshwater is used for agriculture). From an environmental perspective it would be better to grow these crops in a suitable environment and then transport them.

Is Eating Organic Really Good for the Environment?

As explained in this post eating organic is not necessarily ecological. Despite strong public perception of organic agriculture producing better environmental outcomes, conventional agriculture often performs better on environmental measures including land use, greenhouse gas emissions, and pollution of water bodies. There are, however, some contexts where organic agriculture may be better for the environment.

The graph below gives an overview of the environmental impact of various types of crops grown organically and conventionally. As you can see organic crop often require double as much land compared to conventionally grown crops. It is complicated.

Shown is the relative environmental impact of organic and conventional agriculture across various ecological and resource indicators based on a meta-analysis of 164 published life-cycle analyses (LCAs) across 742 agricultural systems. Roughly, lower in the graph means organic is better and higher up in the graph means conventional farming is better. Data source: Clark & Tilman (2017) – Comparative analysis of environmental impacts of agricultural production systems, agricultural input efficiency, and food choice. In Environmental Research Letters. The data visualization is available at OurWorldinData.org<<Link-10>>. There you can find research and more visualizations on this topic. Licensed under CC BY-SA by the authors Hannah Ritchie and Max Roser.

What really matters though is the type of food you eat, not whether it is organic or not. For example, beef (from beef herd) causes emissions 188 times larger than nuts do for the same amount of protein provided. Another thing to note is that if you eat 300 steaks per year you will have a 100 times larger environmental impact from your meat eating compared to someone who eats 3 steaks per year. You don’t have to become a vegetarian to have a smaller environmental impact but quantity matters.

Is Recycling Important?

The common perception that recycling is one of the best things you can do for the environment is not correct. Its impact is often not very large and if not done properly it can be counterproductive. If you throw a greasy pizza box in the recycling, you can ruin the entire batch.

Surveys across 21,000 adults in 30 countries showed that the two actions among twelve that people believed saved the most greenhouse gases were recycling (59%) and upgrading lightbulbs (36%). As it turns out, those two saved the least greenhouse gases among the twelve options. The option saving the most greenhouse gases among the 12 was giving up an SUV, which saved 18 times as much greenhouse gases as recycling. 17% of respondents picked that one.

Photo by Anna Shvets on Pexels.com

According to Our World in Data (and the book Not the End of the World page 114<<Link-6>>), which is based on this research, giving up an average SUV for a sedan would save 3.6 metric ton, or 22.5% of the carbon emissions for the average American. Switching to a plant-based diet would save 2.2 metric ton per person, or 13.8%. Recycling comes in at a savings of 0.2 metric tons according to the same data. EPAs estimates are slightly higher but still low in comparison.

Plastic straws versus paper straws

Producing a plastic straw requires 39 kilojoules of energy and produces 1.5 grams of carbon dioxide emissions. However, producing a paper straw requires 96 kilojoules of energy and produces 4.1 grams of carbon dioxide emissions. So, plastic straws are better for the environment from that perspective. However, this could be compared to a typical passenger vehicle, which emits about 4.6 metric tons of CO2 per year according to EPA. That corresponds to more than 3 million plastic straws and more than one million paper straws.

According to the same article the average passenger vehicle emits about 400 grams of CO2 per mile. So, driving just one mile corresponds to hundreds of plastic straws and paper straws.

Photo by Christopher on Pexels.com
Photo by Sarah Chai on Pexels.com

One advantage of paper straws is that they are easier to recycle, at least under ideal circumstances. Unfortunately, they often get soggy, and recycling plants don’t want that so they often throw them out. Another advantage is that paper straws decompose and don’t end up in our ocean.

However, not only are straws very small items, most of the plastic pollution in the ocean does not come from north America(1%) or Europe (1%). Paper straws versus plastic straws seem like a complex riddle but it may not be an important one. Whether you drive more or drive less is probably a lot more important.

Plastic bags versus paper bags

As with plastic straws versus paper straws plastic bags versus paper bags is a complicated question. From an environmental perspective they both have advantages and disadvantages. Plastic bags are less carbon intensive to produce, are easier to reuse several times, and the production of plastic bags require on average four times less energy than the production of paper bags.

On the other hand, paper bags are decomposable and easier to recycle. However, the chemicals and fertilizers used in producing paper bags create additional harm to the environment. It is a complicated question.

Plastic Ocean pollution. Whale Shark filter feeds in polluted ocean, ingesting plastic. Asset id: 1120768061 by Rich Carey

Having a Significant and Positive Impact on the Environment

Some of the allegedly sustainable practices and actions mentioned above are counter productive and others have a very small effect, for example, carbon emissions savings that are a few grams. According to the “Our World Data” and the book “Not the End of the World” page 114, a compilation of data research, some actions that you can take that will significantly reduce carbon emissions are  (savings in metric tons per year, for flight it is per trip):

  • Giving up an SUV 3.6 tons
  • Go car free (average car) 2.4 tons
  • Switch to plant-based diet 2.2 tons
  • Avoid transatlantic flights 1.6 tons
  • Buy green energy 1.5 tons
  • Switch to electric car (from average sedan) 1.2 tons
  • Switch from electric car to none 1.2 tons
  • Avoid medium flight 0.6 tons (1,700 miles each way going and returning)
  • Laundry in cold water 0.25 tons
  • Hand-dry clothing 0.2 tons
  • Recycle 0.2 tons
  • Upgrade light bulbs 0.1 tons

As you can see in the graphs below, the largest contributor of greenhouse gas emissions in the World and in the United States is electricity and heat. Unfortunately, the composition of the electric grid is something we as consumers have very little control over. We can save energy, get solar panels for our roof, or buy our electricity from green energy companies, but we cannot easily change the composition of the grid. Energy companies and politicians must do that.

However, we can make our voices heard by calling and writing to our representatives. This might be the single most impactful action that you as an individual can take. Your congressman, senator, or state legislator will probably not read your letter. They have hundreds of thousands or millions of constituents and get lots of letters every day. What is likely to happen is that a staff member will skim the letter and note the concern in a database.

Just make sure that your letter is politely written so it does not go in the wastebasket. Also make sure that you are a constituent. Writing to Ted Cruz when you live in Florida is not going to have an impact. They are interested in finding out what the concerns of their constituents are and according to staff members and other information I have come across, this really has an impact.

Data source : Climate Watch (2024). Note : Land use emissions can be negative. OurWorldinData.org/co2-and-greenhouse-gas-emissions| CC BY
Data source : Climate Watch (2024). Note : Land use emissions can be negative. OurWorldinData.org/co2-and-greenhouse-gas-emissions| CC BY
Conclusion

The survey mentioned above showed that among the twelve environmental actions an individual could take, the one with the second to smallest positive impact was the one that the majority thought had the biggest positive impact, despite it having a relatively tiny impact. The actions that could really make a huge difference were hardly considered.

We, the public, are very bad at determining what is good or bad for the environment and what has a significant and positive impact or not, even though the data is out there and we easily can look it up. Maybe the biggest positive impact one could have on the environment is to look up the facts and get better educated.

To see the other Super Facts click here