Climate Change: The Burden of Proof
By Paul Homewood
Reposted from American Thinker:
The Intergovernmental Panel on Climate Change (IPCC) has to provide proof for significant human-caused climate change; yet their climate models have never been validated and are rapidly diverging from actual observations. The real threat to humanity comes not from any (trivial) greenhouse warming but from cooling periods creating food shortages and famines.
Burden of proof
Climate change has been going on for millions of years — long before humans existed on this planet. Obviously, the causes were all of natural origin and not anthropogenic. There is no reason to think that these natural causes have suddenly stopped. For example, volcanic eruptions, various types of solar influences, and atmosphere-ocean oscillations all continue today. We cannot model these natural climate-forcings precisely and therefore cannot anticipate what they will be in the future.
But let’s call this the “Null hypothesis.” Logically therefore, the burden of proof falls upon alarmists to demonstrate that this null hypothesis is not adequate to account for empirical climate data. In other words, alarmists must provide convincing observational evidence for anthropogenic climate change (ACC). They must do this by detailed comparison of the data with climate models. This is of course extremely difficult and virtually impossible since one cannot specify these natural influences precisely.
We’re not aware of such detailed comparisons, only of anecdotal evidence — although we must admit that ACC is plausible; after all, CO2 is a greenhouse gas and its level has been rising mainly because of the burning of fossil fuels.
Yet when we compare greenhouse models to past observations (“hindcasting”), it appears that ACC is much smaller than predicted by the models. There’s even a time interval of no significant warming (“pause” or “hiatus”) during the past 18 years or so — in spite of rapidly rising atmospheric CO2 levels.
There seems to be at present no generally accepted explanation for this discrepancy between models and observations, mainly during the 21st century. The five IPCC reports [1900 to 2014] insist that there is no “gap.” Yet strangely, as this gap grows larger and larger, their claimed certainty that there is no gap becomes ever greater. Successive IPCC reports give 50%, 66%, 90%, 95%, and 99% for this certainty.
[after J. Christy]
Needless to say, there are no sufficient conditions to establish the existence of any significant ACC from existing data. Even necessary conditions based on empirical data, like temperature vs altitude and latitude, cloud cover, precipitation, are difficult to establish.
To summarize, any major disagreement of data with models therefore disproves ACC.
Read the full post here.