More on CO2 and temperatures

I’m still sparring with climate change deniers on Quora. They never give up on their pseudoscience, misinformation, selective data, wrong data, old data, etc. And they seem to think they’re correct and the scientific community including all the professors and others are wrong. Yesterday I posted the following reply to one of the deniers who was talking nonsense. Google doesn’t pick up Quora replies, just initial answers to questions, so I believe it’d be fine to reproduce it here or close to it. It’s a response by a denier mainly quoting another denier, so I’ll use “he” rather than the other denier’s name.

Ah, so something else is pushing temperatures up, not CO2. Perhaps you could tell me what that is, given that solar activity has been falling in recent decades, and given that changes in Earth’s orbit and rotation mean we’re heading for another glacial period, and also given that albedo is having a long term cooling effect, and given that volcanic activity is low, and also given there is no significant change in other greenhouse gases. CO2 has been known to be a greenhouse gas since the 19th century and the science is well known and accepted by virtually all climate scientists as well as all scientific organisations.

The rest of your post quotes a [person’s name] post. hahaha. I corrected him so many times that he has blocked me from making further responses to his posts. Especially amusing were his old and recent photo comparisons of some beach or island and he would conclude there’s no sea level rise, taking no account of tides, erosion, reclamation, different camera angles, or anything else, and his stories of oranges no longer being grown commercially in some areas thus the world has cooled or something.

Anyway, he says he spent months trying to work out the Mauna Kea (he means Mauna Loa) CO2 graphs. I could have told him in five minutes. The red jagged or squiggly line is simply the seasonal effect. CO2 levels go up and down a few ppm over the year. It’s highest in May each year as this is just before plants in the northern hemisphere (where most of the land is) start removing a lot of CO2 from the atmosphere and continue to do so over the warmer months. Once the cold sets in around October, plants and soil release CO2 into the atmosphere and the level increases again through to May. The black line is the annual average and the acceleration of it is quite obvious; place your ruler next to it.

Yes, the graph could start at zero [instead of about 300 ppm] and the line would appear flatter. But that would be like deniers drawing a temperature graph with a range of, say, 0–100°F and drawing a virtually flat line across the middle and declaring no temperature increase (although you can still see the increase in these graphs). It’s better to fill most of the graph space so that people know what’s going on. Using Kelvin would be even more ridiculous as it starts at absolute zero, equal to –273.15°C. No one would see anything or know what was going on in terms of temperature change in any locality or larger area and whether raw or adjusted temperature data was used, but that’s what deniers want; again, it’d be proof, to them, that there’s no warming.

You cannot equate one unit of CO2 however measured with one unit of temperature however measured, as he seems to be doing. He seems to be trying to say that one degree change in temperature can be compared with a 1 ppm change in CO2 level. You can’t compare or equate two different things like this. And what if you converted to Fahrenheit or to ppb or parts per 10,000 or whatever? It would be quite arbitrary. You could muck around with the graph and show anything you wanted to show. Thus you simply can’t say the “slope above is 83 times that of the temperature”, as he does, and then worst of all, conclude “no relationship” when clearly there is one.

Re the temperature data, he says “we are finding much fraud in them”. Who’s “we”? There’s no fraud. All weather bureaus and relevant government departments and scientific organisations around the world adjust the raw temperature data to get a picture of actual temperatures and, importantly, temperature change over time, rather than simply what the thermometers say. This takes into account things like heat islands, weather station moves, and changes in temperature measuring instruments and methods. These things need to be taken into account or temperature graphs showing change over a number of decades are meaningless.

Yes, the mass of CO2 in the atmosphere is about 2 GT. Our annual output is about 38 GT. But he seems to have forgotten about the natural environment which releases about 770 GT a year. But the natural environment takes out about the same amount while we don’t take any out, thus the build up in CO2 level. The CO2 retained and sequestered figures include the contribution of the natural environment. Plants and oceans are not taking up all our CO2 emissions and this is why the level is increasing each year. And it’s an ongoing process. Some CO2 goes through the cycle many times in a year; other molecules stay in the atmosphere or ocean a long time.

Early in his post, he says that the Bakken field in the US has 20 trillion barrels of oil reserves and that this will last 500+ years. This figure doesn’t seem to appear anywhere else on the web and is at least 500 times higher than any other estimate for that field. It’s also at least 10 times higher than world reserves, about 1.5–2 trillion barrels, which is about 60 years’ worth.

And here’s another short reply yesterday to the same person: The greenhouse effect doesn’t contradict the second law of thermodynamics at all. A cold object can and does pass heat to a warmer one. It’s the NET flow that always goes from the warm object to the cold object. The temperature doesn’t increase through this process; it just slows the cooling. When this happens over a period of time and the amount of CO2 in the atmosphere increases, then the atmospheric temperature down the track will be warmer than if CO2 doesn’t change or it decreases. Thus a greenhouse gas doesn’t actually warm the planet but slows the cooling of it. Instead of escaping, some of the heat is radiated back to the surface. Greenhouse gases act like a blanket keeping the heat in rather than generating any extra heat. The second law also assumes an isolated system (sans the sun). Numerous experiments and observations since the 19th century show that there is a greenhouse effect and that CO2 is part of it.