Tuesday, November 03, 2015

Paris in the Winter..

It is an interesting fact that the models used to predict climate in 2100 are running very hot.

That is, they do not do well when compared to either observed measurements from land based instruments or satellites collecting temperature data. Compared to the actual temperature rises since 1980, the average of 32 top climate models (the so-called CIMP5) overestimates these rises by 71-159%. A new Nature Climate Change study shows that the prevailing climate models produced estimates that overshot the temperature rise of the last 15 years by more than 300%. Given that temperature rises are very minute (we are talking 100th of a degree centigrade), these error ranges are significant. Don't get this wrong – the climate is changing. It is just that our models for anticipating these changes are not at all working well. The graph below shows the difference between model predictions, surface temperature measures and satellite measures. It is pretty dramatic.

This is important, since it is these models which give rise to at least some of the policy and adaptive concerns which will be the focus of COP21 in Paris in just a few days time.

To make matters worse, there is little agreements between the surface temperature measures taken from weather stations around the globe and adjusted in largely appropriate (but sometimes problematic) ways and the measures taken by satellite. That is, if we take the satellite data as the most accurate then the difference between the models and the actual data is substantial – 159%.

Then there is the elephant in the room problem. There has been very little (if any) rise in THE rate of global surface temperature warming in the last 19 years, despite substantial increases in levels of C02. Several studies show that the slowdown could be caused by a natural cycle in the Atlantic or Pacific that caused temperatures to rise more in the 1980’s and 1990’s but that has slowed or stopped global warming now. Even the UK Met Office accepts that this is the case. Global warming is real, but it has probably been exaggerated in the past by the poorly designed climate models.

Then there are other complications with the general theory of climate change on which COP21 policy analysts base their case:

  1. The Antarctic ice expanse is growing not shrinking, according to NASA. Research, published in the Journal of Glaciology, found Antarctica gained 112 billion tons of ice per year from 1992 to 2001 and 82 billion tons of ice per year from 2003 and 2008. Eastern Antarctica gained 200 billion tons of ice per year from 1992 to 2008, according to the NASA study, outweighing ice losses from western Antarctica totalling 65 billion tons per year. This means the south pole is actually contributing to sea level declines, not sea level rises. A similar observation could be also be made about the Arctic – sea ice extent this year still has 2000 km3 more ice than the 2012 record breaking year.
  2. We all are aware that sea level rises threaten small island states, such as Kirabati. But the situation is actually quite complex. Whie some of the islands are threatened, many are actually stable or growing. In a variety of studies some 80% of the “threatened” islands have either stayed the same or grown. Professor Paul Kench of Auckland University, who has studied these islands, makes clear that “the physical foundation of these countries will still be there in 100 years, so they perhaps do not need to flee their country”.
  3. Sea level rises are occurring, but not as we may think. Like all aspects of climate, there are various regional variations – in some places the seas are rising quickly, in other places they are falling. Simple explanations do not work without taking into account a complex array of factors. For example, sea level along the west coast of the United States has actually fallen over the past 20 years because long-term natural cycles; yet in other parts of the world, seas have risen by 9” since 1992.

So the science is still unfolding. No serious scientists doubts that climate change is happening. But equally, few take the simple human caused climate change (more C02 = hotter climate) less seriously. Rather than being such a simple problem, climate scientists see understanding the science of climate change as a wicked problem.

So when we listen to those attending the Paris summit, including our Prime Minister Trudeau, we should be reminded that the basis of their deliberations and decisions is an emerging science which is still very problematic.

Richard Tol, an economist and statistician, is the Professor of the Economics of Climate Change at the Vrije Universiteit, Amsterdam and he is ranked among the “top 50 most-cited climate scholars”. He has well over 200 publications in academic journals and is a lead author for the International Panel on Climate Change (IPCC).  He thinks little of COP21 and the Paris process. In a recent speech he said that “the UN climate summit will “ultimately proven to be a futile effort” and achieve nothing more than “sending people to Paris for no apparent reason other than to keep these people well-travelled”.

We seem to have created a problematic process built on a theory which is still in development and not looking too healthy. Lets hope Tol is wrong. But you have to wonder..



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