Category — Endangerment Finding (EPA)

In my last post, I pointed out a problem with the EPA’s major finding that:

Most of the observed increase in global average temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic GHG [greenhouse gas] concentrations.

I showed that it could be reasonably and straightforwardly argued that less than half of the warming since 1950 contained in the “observed” global temperature history can be attributed to anthropogenic greenhouse gas emissions. This is bad for the EPA, as this finding was simply parroted by the EPA from the IPCC Fourth Assessment Report (AR4)—a report relied on heavily by the EPA in underpinning its Endangerment Finding (that greenhouse gases released by human activities “threaten the public health and welfare of current and future generations.”). When the IPCC is wrong, so is the EPA.

Another new problem with the IPCC’s AR4 was reported earlier this week. This one involved the IPCC’s reliance on a book chapter instead of the peer-reviewed literature to conclude that sea ice extent around Antarctica had changed little since the late 1970s. In fact, it is well-established in the scientific literature, dating both prior to and subsequent from the production of the AR4, that there has been a statistically significant increase in the extent of sea ice in the Antarctic. That the IPCC AR4 projects Antarctic sea ice declines to accompany global warming, it is little wonder why the IPCC AR4 Chapter 4 authors wanted to downplay the actual behavior of Antarctic sea ice.

The Antarctic sea ice problem adds to an ever growing list of problems uncovered recently (since the EPA’s Endangerment Finding) that exist within the IPCC AR4 reports. Other errors involve IPCC findings on Himalayan glaciers, Amazon rainforests, African agriculture, Dutch geography, attribution of extreme weather damages, and several others.

And none of these problems have been exposed as a result of the Climategate email release. Well, maybe as a general result of the heightened nature of inquisitiveness that the Climategate emails evidenced as being warranted, but not as a direct result of the content of the any particular email.

But, don’t let this leave you thinking that the Climategate emails are just much ado about nothing, as many IPCC apologists would like you to believe. Far from it. [Read more →]

[Editor note: The author has added an update at the end showing why it can be reasonably argued that anthropogenic greenhouse gases may be responsible for less than half of the observed warming since the mid-20th century]

Back in December, the EPA announced that it had determined that greenhouse gases released by human activities “threaten the public health and welfare of current and future generations.” This “Endangerment Finding” is the first step toward EPA’s issuing regulations aimed at restricting GHG emissions in the U.S.

Unfortunately for the EPA, a major pillar of support of the Endangerment Finding—that “most” of the “observed warming” since the mid-20th century is from greenhouse gas emissions from human activities—has been shown by recent scientific research in major peer-reviewed scientific journals to be largely in doubt.

Add this result to the list of problems that seems to grow longer with each passing day as more IPCC gaffes are uncovered and Climategate emails are parsed. One has to wonder just how long it will be until the EPA is challenged to reconsider its Endangerment Finding.

The basis for the Engangerment Finding is contained in the EPA’s Technical Support Document for Endangerment and Cause or Contribute Findings for Greenhouse Gases under Section 202(a) of the Clean Air Act (TSD). The TSD does not describe any new, independent research carried out by the EPA (because they did not undertake any), but instead largely summarizes the findings of the Intergovernmental Panel on Climate Change (IPCC).

One of the key statements (from page 2 of the Executive Summary of the EPA’s TSD) is this—a simple mimic the IPCC AR4 finding:

Most of the observed increase in global average temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic GHG [greenhouse gas] concentrations.

As I shall show, this statement is no longer tenable.

Background

First off, here is my take on what the EPA/IPCC is claiming.

For “most” I’ll assume “more than half.” For “observed increase in global temperature” I’ll assume the linear least-squares regression trend through the most recent version of the global temperature dataset compiled jointly by the U.K.’s Hadley Center and Climate Research Unit (dataset HadCRUT3). [Read more →]