The recent series of letters and commentary on climate change has been very interesting. The most recent entry by Kevin Ma (July 30) provided what I thought was a good response to Joe Prins and Ken Allred.
Both Ken and Joe point to the IPCC’s mandate to focus on anthropogenic climate change as the “smoking gun” of a hidden agenda. Kevin countered this convincingly (see Myth 34). Further, the IPCC’s mandate doesn’t presuppose that anthropogenic warming is true, it just says to study “… the scientific basis of risk of human-induced climate change.” Seems fairly transparent and practical. But does the IPCC really follow that spirit of scientific inquiry? To decide this I had a look at the 2014 Climate Change Synthesis report (www.ipcc.ch/pdf/assessment-report/ar5/syr/AR5_SYR_FINAL_All_Topics.pdf). It is 80 pages long and, since I needed to clean the garage on the weekend, I focused on the first half as it talks about evidence and conclusions.
The report includes clear definitions of terms (e.g. p 37), error bars on graphs (p 41, 42, 45, etc.), ratings of uncertainty on findings (e.g. p 48, 53), discussions of both natural and anthropogenic causes, and presentation of results that don’t match predictive models (e.g. p 43). Section 1.1 describes observed changes, and section 1.2 talks about natural and anthropogenic causes. The report first looks to see if the climate is indeed changing, then tries to determine what portion is natural vs. anthropogenic. Seems to me they are following their mandate. Also, no hidden agendas so far.
The report states on p 48 “It is extremely likely that more than half of the observed increase in global average surface temperature from 1951 to 2010 was caused by the anthropogenic increase in GHG concentrations and other anthropogenic forcings together (Figure 1.9).” Joe, however, claims it is only 5% without naming a source.
Joe refers to the Holocene period, which ended the last glacial age, indicating temperatures were warmer than today so our current situation is “nothing unusual.” I looked into this and ended up at the National Oceanic and Atmospheric Administration (NOAA) website with the following clarification: “In summary, the mid-Holocene, roughly 6,000 years ago, was generally warmer than today, but only in summer and only in the northern hemisphere. Moreover, we clearly know the cause of this natural warming, and know without doubt that this proven ‘astronomical’ climate forcing mechanism cannot be responsible for the warming over the last 100 years.”
Apparently sea levels rose 60m during the Holocene, so not only was the temperature change caused by astronomical factors and not CO2, it had a huge effect on coastal areas and islands. We are talking about an estimated temperature difference of 1C-4C in the northern hemisphere in the summer. That doesn’t seem like a lot, but was enough to melt continental ice sheets, resulting in our current interglacial period. Today’s situation is very different from the Holocene as the Earth’s orbit is not identical, there are 7.4 billion people on the planet contributing to warming and the temperature increase is occurring faster than it did in the Holocene.
Joe advises that we ignore historical temperature data. However, the Holocene warming he cites is based on historical temperature data. Specifically it used ice core samples with a deuterium proxy method, which is also used for long-range temperature plots supporting climate change.
Joe doesn’t trust temperature data from NASA’s Goddard Institute for Space Studies (GISS) because of changes made to the data since 2008. However, the GISS states why corrections are made to historical temperature data, referring to the NOAA site for a detailed explanation. From what I can tell interpolating data is reasonable over short spans, and data homogeneity is necessary for proper analysis. If there is distrust of GISS corrections on historical temperature data, the raw data is available for analysis. This is a transparent approach.
Joe says climate science models cannot predict various warm periods in history. Kevin counters this with Myth 27. Further, the IPCC report shows predictions made by 114 models for surface temperature in the last century (p 43). Graph “c” shows that the models do a fairly good job. The NOAA says “Even in the first IPCC assessment (IPCC, 1990), many climatic variations prior to the instrumental record were not that well known or understood. Fifteen years later, understanding is much improved, more quantitative and better integrated with respect to observations and modelling.” It is clear that the Earth’s climate is a very complex system and difficult to predict, so I would expect the models to be continually evolving as climate scientists discover new information. This is a normal scientific process.
After finding nothing suspicious with the IPCC, GISS, or NOAA, I looked for additional refutations. Web sites such as globalclimatescam.com and wnho.net appear to be nothing more than incoherent rants with no scientific basis. A general theme of refuters appears to be a mistrust of authorities such as scientific institutions and government organizations. When refuters ask us to “connect the dots” to determine hidden agendas, require us to believe that large groups of people are participating in a deception while keeping silent, point to large scale economic or political ambitions of these groups, assign sinister motivations to insignificant events, comingle facts and speculations with no clear separation or probability, reject all disconfirming evidence and only seeks confirmatory evidence, they cross the line from skepticism into conspiracy theory territory. Sorry, but that’s how it appears.
Since both Ken and Joe claim to be skeptics, I recommend an article on skeptic.com, which talks about why people believe in conspiracy theories (skeptic.com/downloads/conspiracy-theories-who-why-and-how.pdf). After all, a good skeptic should be skeptical of their own beliefs, right?
John Hammond, St. Albert
