Category Archives: Climate Models

The Earth’s Atmosphere is Chaotic, Partially Constrained

A thoughtful response to the recent Cox et al here on climate sensitivity.

“They seem to overlook one very important thing. In their method, they look at “variations in yearly global temperatures”. They are assuming that the envelope created by the variations will reveal an underlying trend, and from that, a measure of climate sensitivity by comparing it to model output. Their analogy in the press release, using a weighted spring reveals their thinking as believing Earths climate as being a “constrained system”.

Earth’s climate does have some constraints, but it also has chaos, and the chaotic nature of the myriad of forces in Earth’s atmosphere is often pushed beyond what is considered a normal for such constraints. Chaos itself becomes a “forcing”. It is why we get occasional extremes of weather and climate.  Edward Lorentz was the first to describe the chaotic nature of the atmosphere with his “butterfly effect” paper in 1972. “ click here

Cloud cover has cooling effect on climate models

“Princeton University researchers have found that the climate models scientists use to project future conditions on our planet underestimate the cooling effect that clouds have on a daily — and even hourly — basis, particularly over land.” click here

IPCC Model-Based Wind Energy Projections Speculative at Best

A direct quantifiable relationship between carbon dioxide levels and atmospheric wind velocity and direction does not exist. But the warming effect from carbon dioxide could indeed exacerbate atmospheric temperature differentials which directly influence wind. But other atmospheric factors provide a cooling effect. There are underlying assumptions behind this study which make these projections speculative at best. Nevertheless, this effort represents a lot of work by very talented scientists which could contribute to the discussion of wind energy resources on a macro-level.

Kristopher B. Karnauskas, Julie K. Lundquist, Lei Zhang. Southward shift of the global wind energy resource under high carbon dioxide emissions. Nature Geoscience 2017 doi:10.1038/s41561-017-0029-9

The use of wind energy resource is an integral part of many nations’ strategies towards realizing the carbon emissions reduction targets set forth in the Paris Agreement, and global installed wind power cumulative capacity has grown on average by 22% per year since 2006. However, assessments of wind energy resource are usually based on today’s climate, rather than taking into account that anthropogenic greenhouse gas emissions continue to modify the global atmospheric circulation. Here, we apply an industry wind turbine power curve to simulations of high and low future emissions scenarios in an ensemble of ten fully coupled global climate models to investigate large-scale changes in wind power across the globe. Our calculations reveal decreases in wind power across the Northern Hemisphere mid-latitudes and increases across the tropics and Southern Hemisphere, with substantial regional variations. The changes across the northern mid-latitudes are robust responses over time in both emissions scenarios, whereas the Southern Hemisphere changes appear critically sensitive to each individual emissions scenario. In addition, we find that established features of climate change can explain these patterns: polar amplification is implicated in the northern mid-latitude decrease in wind power, and enhanced land–sea thermal gradients account for the tropical and southern subtropical increases.

Climate Models Useful but Unreliable for Forecasting

“His paper argues that the methods used by the establishment climate science community are not fit for purpose and that a new forecasting paradigm should be adopted. A number of papers have been published over the recent years pointing out that climate models have been far short of reliable.” click here

Statistical Study of Model Projections Cannot Overcome Limitations of Underlying Model Assumptions and Poor Data Quality

“Climate models do a poor job of reproducing observed climate. But climate scientists seem to think they can produce more accurate projections by adding fudge factors to their models, to force better agreement between models and observations.” Click here

Transcript of “The Last Debate” on Climate

“The transcript of the workshop is a remarkable document. It provides, in my opinion, the most accurate portrayal of the scientific debates surrounding climate change. While each of the six scientists agreed on the primary scientific evidence, we each had a unique perspective on how to reason about the evidence, what conclusions could be drawn and with what level of certainty.” click here

 

Should there be a “Red Team/Blue Team” Climate Assessment?

“EPA Administrator Scott Pruitt’s proposal for red/blue team assessment is a logical progression from the workshop. The hostile reaction it elicited from leading consensus advocates strongly suggests that they fear debate. Climate scientists whose mission is to advance scientific understanding have nothing to fear and much to gain. Those who seek to use climate science as a policy battering ram have good reason to feel uncomfortable at the prospect. The biggest winner from a red/blue team assessment will be the public. If people are to buy into policies that will drastically alter their way of life, they should be fully informed of the consequences and justifications. To do otherwise would represent a subversion of democracy.” click here