Sunday, March 10, 2013

Climate Models and Public Policy

In recent months, several leading warmists have made explicit statements that mean global temperatures have not risen since 1997. These include Rajendra Pachauri, chairman of the UN’s Intergovernmental Panel on Climate Change, James Hansen of Nasa, and the Met Office - all had to conceded that the warming trend has stalled virtually to a standstill. They accept that there was a modest temperature rise in the 20th century, as a continuation of the warming that began 200 years ago as the world naturally emerged from those centuries of cooling known as the Little Ice Age. But the 0.5C rise between 1976 and 1998 was no greater than the 0.5C rise between 1910 and 1940 (with 35 years of cooling between them, so that the net rise in the past century has been only 0.8C). These data do not, however, deter them from suggesting that the end is neigh and we have just months to act boldly to reduce CO2 emissions to prevent the catastrophe of global warming beyond the 2C “threshold” that was picked to signal doom.

What is the source of their continued concern? Is it data from actual observation? In part yes. They are working on a theory that the primary cause of warming is CO2 emissions from human activity. It is a theory, and one to which many subscribe. But if there has been no significant warming since 1997 but CO2 has continued to rise in this period, which it has, would you not think that some issues about this theory would begin to surface?

The actual evidence is not what is driving the concern. It is the virtual science which climate scientists not depend on to support the warmist view. A variety of computer models continue to tell us that warming is continuing and that we need to be alarmed at the rate of CO2 emissions. These all suggest that the current time is the warmist period on the planet in between 4,000 and 11,000 years. Yet some 700 scientists in 400 different institutions 40 countries in peer reviewed papers all agree that it isn’t. The medieval warm period was much warmer than at present.

Computer models depend on the data and analysis framework programmed into them. Currently, none of the models in use when used to replicate the climate for the last 100 years can do so. A paper published this last January in the Journal of Climate finds that climate models have little to no ability to provide skillful forecasts of global surface temperatures on timescales of a decade or more. According to the author, Matthew Newman (University of Colorado), "these results suggest that current coupled model decadal forecasts may not yet have much skill beyond that captured by multivariate red noise." In plain English: not much better than a table of random numbers.

A paper published last Decemeber in the Journal of Geophysical Research compares observations of wind speeds over China from 1971-2005 to the results from 9 IPCC AR5 climate models for the same period and finds that all 9 models show a "substantial positive bias," i.e. a substantial exaggeration, of wind speeds. The paper adds to many other peer-reviewed papers demonstrating that IPCC climate models greatly exaggerate extreme weather, cyclone activity, wind storms, droughts, and floods.

Also last December, several scientists reported in the American Meteorological Society’s peer-reviewed Journal of Climate:
“We examine the annual cycle and trends in Antarctic sea ice extent (SIE) for 18 Coupled Model Intercomparison Project 5 models that were run with historical forcing for the 1850s to 2005. Many of the models have an annual SIE cycle that differs markedly from that observed over the last 30 years. The majority of models have too small a SIE at the minimum in February, while several of the models have less than two thirds of the observed SIE at the September maximum. In contrast to the satellite data, which exhibits a slight increase in SIE, the mean SIE of the models over 1979 – 2005 shows a decrease in each month, with the greatest multi-model mean percentage monthly decline of 13.6% dec-1 in February and the greatest absolute loss of ice of -0.40 × 106 km2 dec-1 in September. The models have very large differences in SIE over 1860 – 2005. Most of the control runs have statistically significant trends in SIE over their full time span and all the models have a negative trend in SIE since the mid-Nineteenth Century. The negative SIE trends in most of the model runs over 1979 – 2005 are a continuation of an earlier decline, suggesting that the processes responsible for the observed increase over the last 30 years are not being simulated correctly.” (my emphasis).

I could go on. There are hundreds of critiques of these models, including some from those responsible for them. Gary Strand, a software engineer at the federally funded National Center for Atmospheric Research (NCAR), admitted climate model software “doesn't meet the best standards available”. In a comment he posted on the website Climate Audit, he said: “as a software engineer, I know that climate model software doesn't meet the best standards available. We've made quite a lot of progress, but we've still quite a ways to go,” (July 5, 2009). NASA’s GISS model E is written on some of the worst FORTRAN coding ever seen and it is a challenge to even get running. NASA GISTEMP is even worse. Yet governments around the world have legislation and regulations enacted or under consideration significantly based on model output from these kind of poor systems.

It is these models that are driving the agenda for climate change warmists, not the evidence from direct observations with one notable exception. That is the observation made by some scientists that extreme weather events are increasing as climate warms. At the opening of the 18 annual United Nations climate summit held in Doha, Qatar, UN climate chief Christiana Figueres, urged governments around the world to “do something about” extreme weather. “We have had severe climate and weather events all over the world and everyone is beginning to understand that is exactly the future we are going to be looking about if they don't do something about it,” she said. Former Vice President Al Gore summed up this view when he wrote: “Every night on the news now, practically, is like a nature hike through the book of Revelations”.

The difficulty here is that this is not the view of scientists whose work is dedicated to the study of extreme weather events, like Roger Pielke Jnr of Colorado. This area of science has been his life’s work and he makes clear that the consensus of science is that extreme weather events are not connected to climate change and also that their incidence is in fact in decline. While noting that the models say something different (because they are programmed to do so), the observations would suggest that the extreme weather events globally are not as frequent or as severe as they have been in the past.

So here is the issue: do we want to make public policy on the basis of flawed and generally wrong models or do we want a policy that is based on more traditional forms of scientific practice?


Tim Goos said...

Hesitant to wade into even commenting on this....

Cherry picking start/end dates of almost any series of geophysical series can demonstrate either what you want or counter what you don't want. Suffice to say, I find your arguments regarding the historical record to be repetitions of some of the most biased writing on the topic.

Our atmospheric models are incomplete and imperfect. But, they are substantially better than any alternative method I am aware of for gauging the impact of emissions into the atmosphere. Substantially. The harsh reality is that, as the models improve, we reduce the uncertainty around what the change will be - our improvements neither create an unexpected ten degree warming or a warming of just .5 degrees.

I strongly believe we should be making public policy decisions based on our observations and our models. Our models told us the Arctic would be most sensitive. The loss of ice accelerates each year and our models suggest we have decades only before we have seasonal ice free periods. Yes, Canada should absolutely be making policies to deal with the consequences.

In Alberta, our models and our observations tell us the time for our glaciers to store water for us is coming to an end. We absolutely should be planning our investments to consider what the change in stream flow will mean to our industries, our society, our people. Absolutely. Particularly given most of our rivers are over-allocated today.

If we follow the climate skeptics, we will fundamentally fail our children and our grand-children.

oldroyd said...

As lay persons, we have to wade (or media-pick) our way through mountains of material. Much of this is from media-picking bloggers driven by ideological beliefs rather than scientific scepticism. We are caught up in a culture war between conflicting ideologies (‘warmists’ vs. ‘deniers’ who style themselves ‘climate realists’) on why we have global climate disruption, its rate of change and its consequences. Your blog led me to some of the ‘anti-warmist’ websites and their connections with other ideological campaigners. This counterbalances my own ('warmist'?) media-picking bias.

Your link led to CFACT’s Morano, who is the former producer for the Rush Limbaugh TV show and speech writer for James Inhofe (R-OK). I watched some of his Fox News punditry with incredulity after the many academic lectures that I have accessed on the clmate issues. Maybe you have more faith in CFACT than my first visit gives me. I appreciate your stance on the need to be sceptical of conclusions from climate modelling, but I am rather taken aback by your faith in sources such as CFACT and Stephen Goddard’s blog ‘Real Science’. Goddard has primarily published using a pseudonym, and it is unlikely he has ever published in a peer-reviewed journal on the subject.

I trust university researchers more than bloggers.

Three examples of bias-identifying sources that inspire some confidence: – remarkable lecture “Critical Thinking on Climate Change: Separating Skepticism from Denial, with brilliant power point presentation. – Presentation by Naomi Oreskes, author of Merchants of Doubt: How a Handful of Scientists Obscure the Truth about Climate Change. – expose by ‘potholer54’, of how long term temperature analyses have been doctored to hide the current rapid increase in global temperatures that considerably exceed those of the Medieval Warm Period

Do I trust modelling of trends?

The AMS Journal of Climate article on SIE suggests the models examined do not to fit past data and you cite this to imply that there is consistent bias in one direction by the IPCC and others with other climate models (SIE is but one measure) “driving the agenda for climate change warmists”. Would this not constitute a conspiracy theory of incredulous proportions and why would so many conspirators be so motivated?

One motivator would be political orientation – are those who do the IPCC meta-analysis of scientific peer-reviewed papers primarily liberals opposed, for example, to the corporate interests of big business? I am less inclined to think that this is so than to believe to ideologically driven campaigns of CFACT and Fox News. The politicisation of such a vital issue is much to be lamented.