Climate: The Unsettled Science

Despite what gets reported in the news media, there are good climate scientists out there, quietly laboring away at that “settled science.” They are actually trying to understand climate instead of making unsubstantiated, bombastic predictions about future global warming. As a result, several recent papers have cast additional doubt on the validity of climate models as they now stand. In one, wide variation in solar radiation at the top of the atmosphere adds to the major errors in basic physics inherent in the so-called “state of the art” climate models. Another paper, on aerosol radiative forcing, casts doubt on the fundamental assertion of climate alarmists regarding the warming power of CO2. Adding to the stink over the settled science claim, the journal Nature carried a news article that says such assertions are “absolutely not true” and pleads for a new crop of physicists to help unravel the persistent ongoing climate mysteries. The outlook for climate science is cloudy indeed.

There have been literally hundreds of assertions that climate models get it wrong. Proof of this can be seen in their dismal failure to predict climate change over the past 18+ years. The current crop of climate models supposedly embodies state of the art knowledge regarding Earth's climate—knowledge that is supposedly “settled science.” The inanity of this claim can be seen in a paper published in Geophysical Research Letters, which finds astonishingly large errors in the most widely used climate models. These errors are due, state the authors, to incorrect calculation of solar radiation and the solar zenith angle at the top of the atmosphere.

In “On the Incident Solar Radiation in CMIP5 Models,” Linjiong Zhou et al state: “Annual incident solar radiation at the top of atmosphere (TOA) should be independent of longitudes. However, in many Coupled Model Intercomparison Project phase 5 (CMIP5) models, we find that the incident radiation exhibited zonal oscillations, with up to 30 W/m2 of spurious variations. This feature can affect the interpretation of regional climate and diurnal variation of CMIP5 results.”

According to one analysis, the supposed radiative forcing from all man-made CO2 generated since 1750 is 1.68 W/m2, according to the IPCC (see below). In comparison, the up to 30 W/m2 of “spurious variations” from incorrect calculation of solar zenith angle discovered by the authors is up to 18 times larger than the total alleged CO2 forcing since 1750.

And this scientific faux pas is found in more than one climate model. Quoting from the paper's abstract:

Annual incident solar radiation at the top of atmosphere (TOA) should be independent of longitudes. However, in many Coupled Model Intercomparison Project phase 5 (CMIP5) models, we find that the incident radiation exhibited zonal oscillations, with up to 30 W/m2 of spurious variations. This feature can affect the interpretation of regional climate and diurnal variation of CMIP5 results. This oscillation is also found in the Community Earth System Model (CESM). We show that this feature is caused by temporal sampling errors in the calculation of the solar zenith angle. The sampling error can cause zonal oscillations of surface clear-sky net shortwave radiation of about 3 W/m2 when an hourly radiation time step is used, and 24 W/m2 when a 3-hour radiation time step is used.

In another paper, this one appearing in the Journal of Climate 2015, Bjorn Stevens of the Max Planck Institute for Meteorology in Hamburg, throws more water on the fire by asserting that an aerosol forcing more negative than −1.0 W m−2 is “implausible.” In “Rethinking the lower bound on aerosol radiative forcing,” Stevens finds that the values for aerosol radiative forcing in current climate models are wrong. Here is the abstract.

Based on research showing that in the case of a strong aerosol forcing, this forcing establishes itself early in the historical record, a simple model is constructed to explore the implications of a strongly negative aerosol forcing on the early (pre 1950) part of the instrumental record. This model, which contains terms representing both aerosol-radiation and aerosol-cloud interactions well represents the known time history of aerosol radiative forcing, as well as the effect of the natural state on the strength of aerosol forcing. Model parameters, randomly drawn to represent uncertainty in understanding, demonstrates that a forcing more negative than −1.0 W m−2 is implausible, as it implies that none of the approximately 0.3 K temperature rise between 1850 and 1950 can be attributed to northern-hemispheric forcing. The individual terms of the model are interpreted in light of comprehensive modeling, constraints from observations, and physical understanding, to provide further support for the less negative (−1.0 W m−2) lower bound. These findings suggest that aerosol radiative forcing is less negative and more certain than is commonly believed.

Bottom line: By reducing the assumed net cooling effect of aerosols the warming effect of greenhouse gasses, notably CO2, must be decreased (the warming is not changed). The upshot of both of these papers, one saying there is more solar forcing and one saying there is less negative aerosol forcing, is that current estimates of climate sensitivity due to CO2 are too high. This, in turn, makes all the model predictions run too hot—just as we have seen over the past two decades. Yet the climate catastrophists refuse to accept that carbon dioxide plays a less significant role than they thought.

Science rolls on and all respectable scientists tactfully ignore the “settled science” meme. Some, however, feel the need to set the record straight, particularly when trying to attract talented young scientists to the field. After all, who wants a career in a field as discredited and slipshod as mainstream climate science? As we have seen, anyone making a new discovery at odds with existing climate science dogma is attacked, both professionally and personally.

An article appeared in the respected journal Nature in which prominent climatologists try to spark enthusiasm for their field among budding researchers who might otherwise choose astrophysics or cosmology. In “Climatologists to physicists: your planet needs you,” it is plainly stated that thinking the major challenges in physical climate science are settled is wrong.

“That’s absolutely not true,” says Sandrine Bony, a climate researcher at the Laboratory of Dynamic Meteorology in Paris. “In fact, essential physical aspects of climate change are poorly understood.”

Recently, in Nature Geoscience, Bony’s team outlined four of the field’s deepest questions, including how clouds and climate interact and how the position of tropical rain belts and mid-latitude storm tracks might change in a warming world. In “Clouds, circulation and climate sensitivity,” they state:

Fundamental puzzles of climate science remain unsolved because of our limited understanding of how clouds, circulation and climate interact. One example is our inability to provide robust assessments of future global and regional climate changes. However, ongoing advances in our capacity to observe, simulate and conceptualize the climate system now make it possible to fill gaps in our knowledge. We argue that progress can be accelerated by focusing research on a handful of important scientific questions that have become tractable as a result of recent advances. We propose four such questions below; they involve understanding the role of cloud feedbacks and convective organization in climate, and the factors that control the position, the strength and the variability of the tropical rain belts and the extratropical storm tracks.

“[A]lthough general circulation models constitute one of the pillars of climate science, shortcomings in their representation of clouds, precipitation and circulation have persisted for many generations of models,” say the authors. “These shortcomings cause significant problems that remain even when other complexities in the system are stripped away.”

“We too quickly turn to the policy implications of our work and forget the basic science,” adds Bjorn Stevens, a director at the Max Planck Institute for Meteorology in Hamburg, Germany, and a co-author of the Nature Geoscience paper.

According to the Nature article, physicists agree that climate science is not a big attractor of physics students. “Very few, and rarely the best, choose to do a master thesis in climatology,” says Thierry Fichefet, a physicist and climate modeller at the French-speaking Catholic University of Leuven in Belgium. “Talented physicists commonly go into more glamorous fields such as astronomy, cosmology or particle physics.” Quoting the article: “According to the American Institute of Physics in College Park, Maryland, 49 PhDs were awarded in atmospheric chemistry and climatology in the United States in 2013, compared with 303 for astronomy and almost 2,000 each for physics and mathematics.”

Evidently, if the science is settled they settled for wrong. There are three major points to be garnered from the articles cited above:

  • First, climate science is far from settled, regardless of what alarmist blowhards tell us
  • Second, conscientious climate scientists realize that new talent is needed to solve the problems that others in their field won't admit exist or try to solve
  • Third, the contentious and ossified field of climate science is not attracting top shelf scientific talent

This is the state of climate science: unsettled science, a recalcitrant closed community, and a dwindling pool of scientific talent. This is hardly surprising. After all, who wants to work on “settled science?”

Be safe, enjoy the interglacial and stay skeptical.