One of the best things about Forensic Science is not only that it can work with very small samples, but that the conclusions drawn are very large. What’s more, it is tested twice-first by other scientists in all the usual ways like conferences, learned journals and many an earnest water cooler moment. Then it goes to court and gets tested by barristers who, despite whatever personal defects they might have, are possessed of razor sharp minds and can detect any error or illogicality. It’s the ultimate test of the scientific method. Which is actually very easy. Look very hard at something. Is it real? How does it differ from what you know? What does it let you predict?
Oddly enough. it was using this method in climate science which provided the clinching proof that humans are causing global warming. As every schoolchild knows, carbon mainly comes in two forms: 12C and 13C. And these are being constantly recycled through living things and the atmosphere. Because plants generally like to work with 12C they absorb more of it from the atmosphere. So if you measures the ratio of 13C/12C it’s higher in plants than it is in the atmosphere as a whole. But because of the recycling, the atmospheric level should be stable. Which it was for many thousands of years. But if you start burning lots and lots of plant material, especially in the form of coal, that ratio will change. Which it has since about 1850. (Did we hear someone say “Industrial Revolution”?) Since when the atmospheric 13C/12C ratio has been falling steadily as more and more 12C goes up the chimney. You’re breathing it in too, but that’s another story. We have a link below to to the Wiley dummies website, which we always find to be a marvellous source of clear explanation on many topics.
So here’s some questions for those Dog and Duck types who spend too much time swallowing the output of certain TV channels whole.
How much has the 13C/12C ratio changed since 1850? Why has it changed? If it is not caused by burning fossil fuels, what is the alternative explanation? If the effect is cyclic, how long are the cycles? How have they changed in relation to other natural cycles? What other evidence can you offer to make me believe what you say?
We don’t know what answers they will give. But we have noticed that people who start shouting, change the subject or allege conspiracies show that they don’t know what they’re talking about on any subject.
Isotopes: How Do Scientists Know that Humans Cause Global Warming? – dummies
#globalwarming #carbonisotopes #CO2 #climatechange #denialists