Originally Posted by biker1
(Post 2379986)
While you cannot run a controlled experiment on the planet, we do know to a high probability that the anthropogenic increase in the global mean surface temperature anomaly is about 1C. Many people don’t understand the concept of time scales. If you don’t know what an FFT is then it may be hard to understand. The natural climatic variations are probably driven primarily from the 3 Milankovitch cycles, which have time scales of about 20K, 40K, and 100K years. Also, volcanic eruptions have played a part due to the release of CO2 and aerosols. The concern is not, and has never been, natural variations on those time scales. The concern is the rapid increase in observed temperatures over a timescale of 100-200 years and where we will be at the end of the century. We could be at 2-3C warmer by the end of the century. That is actually a lot. Presumably, we will have bent the CO2 emissions curve down by the end of the century, although the impacts will continue for some period of time. We know that increasing CO2 levels impacts the longwave radiative transfer budget and results in stratospheric cooling and lower tropospheric warming. These have both been observed. There are also some positive feedbacks such as warming the atmosphere through increased CO2 levels will increase the moisture content and that can further warm the atmosphere through additional impacts on the longwave radiation budget. Also, as the atmosphere warms the planet’s albedo can drop which impacts the shortwave radiation budget and can lead to further warming. There can also be some negative feedbacks; it’s a complex system. There is a substantial amount of literature available that goes into as many details as you would want. Unless you were trained as a scientist, you may have trouble understanding the material. AR6 is a good place to start. You can also start reading the JoC. The major “doom and gloom” fallacy I hear is that the world is going to end. The other fallacy is that anthropogenic warming is a hoax. The world is not going to end but there will need to be remediation efforts in coastal regions (due to both increasing sea levels and subsidence of the coastal plains). Some geopolitical issues will also probably arise as the warming, and the impacts, vary regionally. So, what can we do? Well, it turns out, not much. 80% of the world’s energy comes from hydrocarbons and that ship is hard to turn. I suspect we can make some progress by mid century but that means CO2 levels will continue to rise for the foreseeable future. In the US, we have little ability to impact anything. While the anthropogenic warming has geographical variations, CO2 itself is well mixed in the atmosphere, both horizontally and vertically. CO2 released in the US doesn’t stay in the US; it mixes globally. We only contribute about 15% of the world’s CO2. It really doesn’t matter what we do. US autos only contribute 3% of the world’s CO2. China and India are the long poles in the tent. If you have ever looked into the details of the Paris Accords you will be surprised at what is in there (and not in a good way).
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