It isn’t a denial but the reality of using models.
There are hundreds of peer reviewed scientific papers which evaluate the accuracy of computer models and discuss their limitations, including climate change models. A model has a level of confidence based on the ruggedness, robustness and reliability of inputs. They provide a level of confidence of the likely outcome of the scenario being tested. Models are often used to test hypotheses before research is a carried out as it can assist in identifying limitations of the proposed research as well as likely outcomes to the tested hypotheses (which could be positive or negative results with varying levels of confidence). I have first hand experience in models with ab high level of positive test confidence, when the research proved otherwise as not all inputs to the model were known or adequately represented.
As more iterations of the models are undertaken including new information such as outputs of real scientific experiments or environmental data, like that done for climate change models, models can be calibrated which can improve the level of confidence with the model outputs and also the likely outputs.
Like any credible organisation (rather than a vested anti-skeptical group with vested interests), the Intergovernmental Panel on Climate Change (IPCC - the the recognised leading intergovernmental on climate change) in their reports discusses and evaluates the models used as the basis for their findings and the limitations of the models. The IPCC are also, due to the level of confidence of the models (which incidentally is stated in IPCC reports) use many words like indicate, may and could in commenting on many aspects of climate change being modelled. These same models don’t currently have the level of confidence to use words like will and would. It is likely that a change in wording will occur as the models develop further and real environmental results are obtained. It is also plausible that some of their hypotheses will change with new information imputed into the models, while others may be modified or remain similar to that of existing outputs. Others could also be removed.
It is also interesting to note that the IPCC also recognise that for food security, there will be positive outputs of climate change, but also recognise that there will also be negative impacts . The latest IPCC report states that in relation to food security 'Negative impacts of climate trends have been more common than positive ones.Positive trends are evident in some high latitude regions (high confidence)."
In relation to CO2 impact on crops, which has been our past discussion, the IPCC states
“Rising CO2 may reduce the effectiveness of some herbicides (low confidence). The effects of climate change on disease pressure on food crops are uncertain, with evidence pointing to changed geographical ranges of pests and diseases but less certain changes in disease intensity (low confidence)”
“Climate change will increase progressively the inter-annual variability of crop yields in many regions (medium confidence)”
“On average, agronomic adaptation improves yields by the equivalent of ~15-18% of current yields, but the effectiveness of adaptation is highly variable (medium confidence) ranging from potential dis-benefits to negligible to very substantial (medium confidence). Projected benefits of adaptation are greater for crops in temperate, rather than tropical, regions (medium confidence), with wheat- and rice-based systems more adaptable than those of maize (low confidence). Some adaptation options are more effective than others (medium confidence).”
And in relation to impact on the consumers hip pocket, the jury is out as the IPCC states:
“Changes in temperature and precipitation, without considering effects of CO2, will contribute to increased global food prices by 2050, with estimated increases ranging from 3 to 84% (medium confidence). Projections that include the effects of CO2 changes, but ignore O3 and pest and disease impacts, indicate that global price increases are about as likely as not, with a range of projected impacts from –30% to +45% by 2050.”
It is worth noting that the level of confidence in their assessment is not overly high at this stage (low to medium confidence which indicates that quantification/qualification not overly reliable at this point in time). I expect that the level of confidence will improve when real field data/science inputs eventuates and more iterations of the models occur.
It is also worth noting, while I didn’t reference the IPCC report in previous posts, many of there conclusions are consistent with that stated in my earlier posts from firsthand discussions with some scientists working in the field.
There have been some popular scientists which have provided advice to government which have significantly overstated the risks. The first example which comes to mind is Tim Flannery. It is possibly that he now realises that some of his earlier statements were flamboyant and to make political points, rather than based on sound science.
But taking the statement as a whole in relation to climate change scientists/experts in their field, this statement is not possible to substantiate to whether it is true or not. Some of the statements made today have the potential to be overstated based on today’s best climate modelling, whilst some may be what was thought and others or may change and be proven to be higher/lower into the future. Only time will tell.
As I have indicated above, the best predictor of future behaviour is … past behaviour. If humans sit on the hands and hope climate change goes away without adapting, then the impacts to humans and the consumer will be greater than if the same humans prepared for the future. As humans have historically adapted to their new environments and surrounds, there is no scientific or psychological, reason to why it won’t occur in the future.
