Climate science - We simply aren't there yet.

Two different articles on different subjects but both related to our understanding of global climate change. They illustrate, I think, why there is such a gap between the small, vocal band of self-interested advocates (UN IPCC) and the broader mass of the informed public (meteorologists and everyone else). Advocates like to characterize everyone else as science deniers, knuckle dragging apologists for polluting industrialists. The reality, I think, has always been more complex.

The fundamental challenge is that environment and climate are two knowledge frontiers where we are still discovering fundamental knowledge at a fairly rapid clip. The skeptics, other than the few true knuckle dragging apologists, accept that there is climate change. Climate is a dynamic system and is always changing. Their question is not about whether climate is changing or even whether or to what degree human activities are a material contributor to change. Their question is whether our body of knowledge allows us to make useful and informed decisions. Do our models and the data reconcile with one another (no)?, can our models make usefully accurate forecasts or backcasts (no)? and are we still discovering elements of causation which materially affect our understanding of the dynamics of climate (yes).

Examples:

From Davy Jones’s heat locker from The Economist.

Over the past few years one of the biggest questions in climate science has been why, since the turn of the century, average surface-air temperatures on Earth have not risen, even though the concentration in the atmosphere of heat-trapping carbon dioxide has continued to go up. This “pause” in global warming has been seized on by those sceptical that humanity needs to act to curb greenhouse-gas emissions or even (in the case of some extreme sceptics) who think that man-made global warming itself is a fantasy. People with a grasp of the law of conservation of energy are, however, sceptical in their turn of these positions and doubt that the pause is such good news. They would rather understand where the missing heat has gone, and why—and thus whether the pause can be expected to continue.

The most likely explanation is that it is hiding in the oceans, which store nine times as much of the sun’s heat as do the atmosphere and land combined. But until this week, descriptions of how the sea might do this have largely come from computer models. Now, thanks to a study published in Science by Chen Xianyao of the Ocean University of China, Qingdao, and Ka-Kit Tung of the University of Washington, Seattle, there are data.

It is too early to know if Dr. Tung and Dr. Chen's results are correct or to what degree they are correct but it hardly matters. They illustrate how primitive is our understanding of the relative influences on climate. There is much, much more to be known.

From Models challenge temperature reconstruction of last 12,000 years by Scott K. Johnson.

Climate records, like tree rings or ice cores, are invaluable archives of past climate, but they each reflect their local conditions. If you really want a global average for some time period, you’re going to have to combine many reliable records from around the world and do your math very carefully.

That’s what a group of researchers aimed to do when (as Ars covered) they used 73 records to calculate a global overview of the last 11,000 years—the warm period after the last ice age that's called the Holocene. The Holocene temperature reconstruction showed a peak about 7,000 years ago, after which the planet slowly cooled off by a little over 0.5 degrees Celsius until that trend abruptly reversed over the last 150 years. That behavior mirrored the change in Northern Hemisphere summer sunlight driven by cycles in Earth’s orbit.

A new study published in the Proceedings of the National Academy of Sciences and led by the University of Wisconsin’s Zhengyu Liu delves into a problem with that pattern—and it’s not what climate models say should have happened.

The researchers used three different global climate models to run a series of computationally intensive simulations spanning the last 21,000 years. The simulations were responding to the orbital change in sunlight and the documented increase in greenhouse gases.

The global average temperature in the models did not peak and decline, however, unlike the Holocene temperature reconstruction. The models show that warming out of the last ice age slowed down markedly around 12,000 years ago, but still continued gradually—temperatures increased by about another 0.5 degrees Celsius before the last couple millennia. That puts the peak of the Holocene reconstruction about 1 degree Celsius higher than the temperatures in the models reach.

So, the models and reconstruction of historic temperatures don't agree. Understanding why requires thinking about that orbital change in a little more detail.

I think the challenge is not that anybody really disagrees that change is happening. Its that no one agrees what the change is or, most importantly, how it is happening.

Even if everyone agreed about the reality and direction of change, we still can't do all that much until we have a reasonably robust knowledge of causation. We simply aren't there yet.