False: If CO2 increased five times, it would still not increase the global temperature by more than 1 degree Celsius.

Context

A recent post on the Facebook page "The Bruges Group" claims that the climate crisis isn't real. The post claims that "if co2 increased by 5 times current levels it would still not increase temperature by more than 1 degree" and that the greenhouse effect does not exist. Accompanying this is an advertisement for Jeremy Nieboer's book: "Climate - CO2 Nature's Gift," from which the claim appears to be derived.

In Fact

There is substantial scientific evidence that CO2 in the atmosphere has increased and has already raised global temperatures by about 1 degree Celcius. This increase, caused by human-induced climate change, has significantly impacted the environment. Decades of research and analysis shows that one of the biggest contributors is the burning of fossil fuels. In a 2019 article, NASA atmospheric scientist David Crisp said that humans have increased the amount of carbon dioxide in the atmosphere by 45 percent. He further stated that the concentration of CO2 in the atmosphere is rising and is nearly 412 parts per million – a 47 percent increase since the start of the industrial age and 11 percent since the year 2000.  

Rising CO2 has affected global temperatures. A different NASA article mentions that temperatures have increased in some regions by 1.5 degrees Celcius due to global warming. Meanwhile, an article by the National Oceanic and Atmospheric Administration (NOAA) states that the Earth's average surface temperature has increased by roughly 1 degree Celcius. This increase in carbon dioxide demonstrates that global temperatures have already increased by roughly 1 degree without a fivefold increase in current CO2 levels. If the amount of CO2 rises, so will global temperatures.  

The post also states that there is no greenhouse effect as excess heat is lost to space, and that CO2 has an even concentration across the atmosphere. However, as mentioned by the British Geological Survey, while heat trapped in the atmosphere is lost to space and a proportion of CO2 in the atmosphere is dissolved in the ocean, the CO2 released from burning fossil fuels accumulates as a layer of insulation around the Earth. There is well-established evidence of an enhanced greenhouse effect due to rising carbon emissions.

Although a 1-degree Celcius increase in global temperature sounds small, scientific evidence already shows that it has had a detrimental impact on the environment. As mentioned by NASA, glaciers and sea ice are melting, plants are blooming sooner, and there are more intense heat waves and adverse events like droughts happening faster than scientists predicted. 

The Verdict

Climate change is a genuine problem for the entire planet, and carbon dioxide emissions are creating an enhanced greenhouse effect that has already increased global temperatures. Based on this evidence, a five times increase in CO2 would significantly increase global temperatures. Therefore, we have marked this claim as false.