I took another look at Global Warming these past few days, and I have to say that I'm still not convinced that CO2 increases are leading to increases in global temperatures. I am not even sure that humans are causing the CO2 increases. This isn't to say that it's not happening; just that the evidence doesn't convince me. Not that it matters. I am not someone who needs to be convinced.
I wanted to believe it this time. I was right there. Arctic sea ice is melting to record lows. The last decade was the warmest decade since the middle ages. CO2 is continuing on its ever-present march to higher and higher levels. But when it comes down to the evidence, all that's present is one correlation between CO2 levels and increases in temperature -- and that's all there is to it. Here's what's known: * CO2 is increasing -- pretty much in a linear fashion. * CO2 is a greenhouse gas. But CO2 is an extremely small percentage of the total atmosphere; something like .039%. It's also not a very strong greenhouse gas. Water vapor is something like 55 times stronger than CO2, and water vapor comprises about 2% of the atmosphere. * Temperatures are increasing. Are they? It depends on how you look at it. Temperatures are still lower than they were during the Middle Ages, which were still lower than they were around the time of the Romans. Also, global air temperature hasn't increased since 1998, in the respected HadCRUT4 series. *http://tinyurl.com/9qkytww* The stall is even more visible in sea heat measurements. *http://tinyurl.com/bb2gtbr* And even more visible in the North Atlantic. *http://tinyurl.com/ag89bps ** There is a correlation between increases in CO2 and the global increase in temperature. In fact, there is a very strong correlation, going back to 1958, when CO2 levels were first measured on a regular basis. The correlation is .96, by my calculations, which is extremely high. But correlation cannot show causation here. Throughout history, CO2 levels have varied in step with temperatures. You can even see this variation on an annual basis, as the northern hemisphere varies in temperature from summer to winter. *http://tinyurl.com/b7xvruy *Now look at this. Do you remember 1992-1994? Mount Pinatubo errupted in 1991, which caused the Earth to cool in 1992-1994. Notice here that global CO2 levels also fell significantly. During this cooling, the CO2 level fell, and it fell as a result of the Earth cooling, and not as the cause. *http://tinyurl.com/a6jbxgd ** The Pacific Decadal Oscillation is continuing to cool. This is a huge 60 year cycle, which appears to be entering its cool phase for the first time since 1940. http://jisao.washington.edu/pdo/img/pdo_latest.jpeg * Arctic sea ice is reaching record lows, going back to the 1970s. But Antarctic sea ice is now reaching record high levels, going back to the 1930s. http://www.meto.umd.edu/~kostya/Pdf/Seaice.30yrs.GRL.pdf <http://www.meto.umd.edu/%7Ekostya/Pdf/Seaice.30yrs.GRL.pdf> http://www.dtic.mil/dtic/tr/fulltext/u2/p023549.pdf * Solar activity has been at a record high level during the 20th century. *http://tinyurl.com/bdrb8mf *This may be significant. If there has been warming since the 1800s, and solar activity has been at a record high during this period, and if there is a correlation, then a decrease in solar activity may lead to cooling, and this may be why global warming has stalled now. * Solar activity is significantly declining now. Nasa is predicting a significant drop in solar activity during the current solar cycle. The sun is now the least active it's been since 1915, when global temperatures hit another multi-decadal low. http://solarscience.msfc.nasa.gov/predict.shtml * There is a correlation between solar activity and global temperature. The correlation is not as strong, only .53 as I calculate it, going back to 1880, but still a correlation which is being completely ignored by all serious modelers. And if this correlation is real, then it's highly likely that it's the Sun which is causing the Earth's temperature to vary, and not the other way around. * Amateurs are able to build very good climate models based on solar activity. This one correlates to .87, and forecasts a cooling climate until the year 2050, at least. http://tallbloke.wordpress.com/2012/10/23/the-carbon-flame-war-final-comment/ This is something the professionals are completely overlooking. It may be the Sun that is responsible for the warming Earth. Who would have figured? That's all I've got. But note also, that this is all that anyone has. There's no mysterious proof lying around anywhere. The whole thing is just an inference from correlations. And correlations can't prove anything. There's a strong correlation between the number of firefighters and the size of town fires. Thankfully no one is suggesting that we should get rid of the fire fighters so that we can reduce the town fires. Craig