Posted by blowlamp on 16/08/2022 23:24:46:
Dave.
In case you are unaware: Piers Corbyn is an Astrophysicist, he has a first class degree in Physics from Imperial College and an MSc in Astrophysics from Queen Mary College…
Sounds good, but read the account of Mr Corbyn's career on Wikipedia.
More to the point, science isn't based on playing Personality Top-Trumps. It's a group activity following a disciplined process designed to eliminate error. Scientific method goes through 3 basic stages each requiring more evidence. Hypothesis, Theory, and Scientific Law.
Scientists start with a Hypothesis to be analysed by others. It begins with a reasonable explanation of an observed phenomenon and can be light on evidence. Nothing is accepted simply just because it seems to fit or sounds good, and 'reasonable' means the Hypothesis either has to be consistent with Theory and Laws or addresses why not.
More work is always needed. The validity of a Hypothesis rises when evidence is found to support it and falls when evidence counters it. Weak evidence, such as statistical correlation has far less weight than a repeatable experiment, and one experiment has less weight than many different experiments, and new data found to fit. Negative evidence is as important as positive, perhaps more so, and is numerate except when words explain numbers. Words without numbers are not evidence, nor are assertions or alternatives. How strong a Hypothesis is depends on a consensus. This reduces the possibility of fans promoting nonsense and truths going down the drain because iindividuals don't understand it. Science is hard to understand!
Hypotheses often take decades to develop. They often start close but incomplete and have to be revised. Done in a highly disciplined way and the revision has to stay consistent with everything else. Other scientists check this is so.
When enough evidence has been accumulated, a Hypothesis is promoted to a Theory. Theories are backed by a overwhelming evidence, but, although no-one has been able to show it's wrong, no one has been able to prove it's right. Proof in the strict sense it's proven 1+1 always equals 2, not sloppy 'beyond reasonable doubt legal proof '.
Considering Global Warming as three Hypotheses, and something like them have:
- Rising temperature is a natural phenomenon. Evidence: none. Temperature is rising, and no natural phenomenon such as volcanic activity or solar activity account for the extra heat.
- Rising temperature is due to human activity. Evidence: considerable, increasing for about 30 years, and no new evidence has arisen to gainsay it. (Disbelief is not evidence.) Repeatable experiments: the amount of heat received from the sun is known and the green-house effect of CO2 and CH4 have both been measured in the lab. The amount of CO2 in the air is consistent with trade accounts showing the amount of fossil fuels burned annually. Temperature is rising consistent with theory – predictably.
- Rising temperature are causing Climate Change. Evidence: considerable. Thermodynamics have been studied comprehensively since James Watt and the equations have reached Law status. The science predicting Climate Change due to extra heat is exactly the same as that used to design all heat-engines. Steam Engines, Steam Turbines, Gas Turbines, Jets, Rockets, Hot Air Balloons & Guns all follow the same Thermodynamic Laws, and so does weather. Extra heat changes weather, the average shifts, and average is climate. Left unmanaged it's easy enough to calculate climate change will be disruptive because of the huge amount of energy involved, but it's hard to show exactly where the whip will fall. Safe to predict turbulent weather with more severe extreme events, but no proof my house will be washed away. But the risk to my home and to food supply and other basic human needs rising. It's as serious as it gets.
Personal opinion has almost no role in science. Evidence please, man-in-pub arguments don't help. When a scientific consensus says something is probably true, they're almost certainly right, even if the news is bad.
Dave