Earth’s Ice Ages

By Andy May

The phrase “Ice Age” is poorly defined and often abused, so let’s first define the climate state during most ice ages. It is called “Icehouse Earth.” The earth is in an icehouse state when either or both poles are covered in a thick, permanent icecap (Scotese 2015). Today, both poles are covered in ice year-round, so you may be surprised to learn this is very rare in Earth’s history. In fact, out of the last 550 million years, the earth has had permanent ice caps on one or both poles only nine percent of the time.

An “Ice Age” is best defined as a geologically (or millions of years long) long period of low temperatures. This usually results in the presence of continental and polar ice sheets and alpine glaciers. We are currently living in the Quaternary Ice Age, this is only the fifth significant and severe ice age in Earth’s known history, and, so far it has lasted about 2.6 million years (technically 30+ million years ago when permanent ice appeared on Antarctica). It is the most severe ice age in the Phanerozoic, the geological name for the past 550 million years. Ice Ages are rare, but humans evolved during one, so it seems normal to us.

figure 1.JPG

Figure 1. Christopher Scotese’s geological interpretation of Phanerozoic global temperatures in degrees C. The vertical line on the right side, labeled “PAW” is a projection of possible anthropogenic warming according to a pessimistic IPCC climate model. In 2016 the actual global average surface temperature of the Earth was about 14.5 degrees C. as marked on the plot, in 2019 the temperature is slightly lower at 14.35 degrees according to NASA GISS. The names of the major ice ages were added by the author. After (Scotese 2015)

Continue reading

A Holocene Temperature Reconstruction Part 4: The global reconstruction

By Andy May

In previous posts (here, here and here), we have shown reconstructions for the Antarctic, Southern Hemisphere mid-latitudes, the tropics, the Northern Hemisphere mid-latitudes, and the Arctic. Here we combine them into a simple global temperature reconstruction. Continue reading

Climate Change, due to Solar Variability or Greenhouse Gases? Part B.

By Andy May

In a previous post, Part A here, we discussed the role of oceans, the Earth’s orbit, and human greenhouse gas emissions on climate change. In this post we discuss the impact of solar variability. Continue reading

Population Growth and the food supply

By Andy May

This is the second of seven posts on the potential costs and hazards of human-caused global warming and the impact of humans on the environment. The first post is on humans and the environment (here). The IPCC WGII AR5 Technical Summary, defines “hazards” as follows on page 39:

“The potential occurrence of a natural or human-induced physical event or trend or physical impact that may cause loss of life, injury, or other health impacts, as well as damage and loss to property, infrastructure, livelihoods, service provision, ecosystems, and environmental resources. In this report, the term hazard usually refers to climate-related physical events or trends or their physical impacts.”

The IPCC WGII AR5 report only deals with population growth tangentially, but it has a lot of information on the world’s food supply. The WGII AR5 technical summary states:

“For the major crops (wheat, rice, and maize) in tropical and temperate regions, climate change without adaptation is projected to negatively impact aggregate production for local temperature increases of 2°C or more above late-20th-century levels, although individual locations may benefit (medium confidence).”

As we will show below, there is no indication of a change in the rate of increase in crop yields in the United Nations FAO data. Continue reading



By Andy May

According to Exxon-Mobil, 9% of the world’s energy came from biofuels in 2017. They do not expect this percentage to increase by 2040, and it may go down. For the most part it is a developing world fuel. Primary biofuels include dung, wood, wood chips and pellets. Secondary, or manufactured biofuels include ethanol and biodiesel, which derive from several agricultural products, mainly corn, sugar cane, palm oil, soybeans and canola. The main advantage of using locally sourced wood and dung are their low cost and wide availability. Using imported wood or wood chips for generating electricity, as is done in Europe, is more problematic. Due to the economic and environmental costs of farming the trees, making the wood pellets or chips and shipping them to the powerplants; wood is not a competitive fuel for most powerplants. The energy density is too low. However, if the source of the wood is within fifty miles of the plant, it can be competitive with coal and it may produce fewer greenhouse gases than coal, estimates vary. Ethanol and biodiesel are also more expensive than fossil fuels and must be subsidized to be competitive.

Continue reading

Food Prices and Ethanol Mandates

By Andy May

This post is a follow up to my previous post on biofuels, here we discuss the impact of biofuels on food prices in more detail. Ethanol has been produced in large quantities in the United States for fuel since 1978. That was the year the Congress passed the Energy Tax Act (Tyner 2008) which provided for a 40 cent per ethanol gallon exemption to the gasoline excise tax. This tax exemption for ethanol was increased to fifty cents in 1982.

Continue reading

#biofuels, #food-prices

Key documents in the Exxon-Mobil lawsuit by state Attorneys General

By Andy May

A reader has pointed out that many of the links in my 2016 post on the Exxon-Mobil Climate Papers are busted. This means that the documents have been removed from the internet or moved to another location. I had copies of many of the documents on my hard drive, so I’ve uploaded them and the links to them are below.

First some helpful links to my original posts:

ExxonMobil sues Massachusetts Attorney General

The Exxon Climate Papers

The supporting documents that I could find:

The court case articles

The Exxon Internal memos

The Exxon peer-reviewed papers

Exxon Mobil and Free Speech

Finally, another useful link to and article on ExxonMobil’s court win.

ExxonMobil sues Massachusetts Attorney General

By Andy May

ExxonMobil is suing Massachusetts Attorney General Maura Healey and New York Attorney General Eric Schneiderman, accusing them of unlawfully exercising their powers in a politically motivated investigation of the oil company. The attorneys general have accused the company of misleading investors and the public by withholding internal research about the impact of global warming. A review of publicly available documents from ExxonMobil, both internal and external, did not uncover evidence of any suppressed or withheld ExxonMobil climate research. It appears the company published everything they knew about the subject. They did a lot of research into climate change, but they uncovered no definitive evidence of an impending man-made climate catastrophe and said so publicly. Some ExxonMobil researchers believed that carbon dioxide might be a problem sometime in the future, but they uncovered no definitive evidence of a problem. And, in any case, the concerned researchers presented their concerns to the company management and in public documents, often in peer-reviewed papers. ExxonMobil also had some of their research staff work on every IPCC report.

The attorneys general investigations were carefully coordinated with lawyers and environmental activists in a meeting March 29, 2016. Breakfast and lunch were provided. An attempt was made to keep the meeting secret. Matt Pawa is an environmentalist lawyer who has sued ExxonMobil over climate change and other issues before. An email has him instructing Lemuel Srolovic (chief of the New York Attorney General’s Environmental Protection Bureau) not to confirm his attendance of the March 29, 2016 meeting. Another email shows that there was an attempt to get a signed common interest agreement that restricted sharing information from the meeting. These emails show that there was cooperation between the attorneys general and environmental organizations to “go after” ExxonMobil. The Wall Street Journal has reported that there was an earlier meeting, in January, that included Kenny Bruno (environmental activist with the New Venture Fund) and Bill McKibben (environmental activist, founder of The earlier meeting was specifically to plan a legal attack against ExxonMobil, presumably investor Kenny Bruno would profit from this attack.

As a result, ExxonMobil is suing the attorneys general, accusing them of unlawfully exercising their powers to harass the company. The company has asked Dallas federal judge James “Ed” Kinkeade to declare the wide-ranging subpoenas from the attorneys general unlawful. ExxonMobil has already turned over more than one million pages of documents to the New York attorney general Eric Schneiderman.

Federal Judge James “Ed” Kinkeade has ordered Massachusetts attorney general Maura Heally to come to Texas December 13 to answer questions under oath about her office’s climate change-related probe into ExxonMobil. Ms. Healey has strongly objected (court document here) to the summons.

ExxonMobil accuses the attorneys general of coordinating with lobbyists, lawyers and environmentalists:

“to silence and intimidate one side of the public policy debate on how to address climate change.”

One has to wonder how any company or person can be investigated for withholding information on the effects of man-made climate change when a substantial minority of climate scientists aren’t even sure man-made climate change is significant or dangerous. For the views of a few famous climate scientists that do not believe climate change is dangerous see here.

ExxonMobil has previously taken court action to block a subpoena from the U.S. Virgin Islands attorney general and the attorney general backed off of that case. They successfully argued that the subpoena was an unwarranted fishing expedition. The filing states:

“The chilling effect of this inquiry, which discriminates based on viewpoint to target one side of an ongoing policy debate, strikes at protected speech at the core of the First Amendment.”

That is certainly true. This sort of “environmental shakedown” of lawful, productive American companies for profit needs to be stopped. One of the best ways to do this is tit-for-tat. If they go after the company, the company should go after them. We applaud ExxonMobil’s suits and hope they continue the fight. Make this as costly and as embarrassing as possible for New York and Massachusetts!

Energy and Society from now until 2040

By Andy May

ExxonMobil released its 2017 Outlook for Energy, A View to 2040 in mid-December. David Middleton has written that the report reveals wind and solar will supply a whopping 4% of global energy by 2040! He also reports that wind and solar capacity will grow, but we will only be able to utilize 30% of the wind capacity and 20% of the solar capacity due to their intermittent nature. This is true, but the report has much more to say and this year the nomination of ExxonMobil CEO Rex Tillerson for Secretary of State makes it even more important. Here we will cover some the other numbers in the report. Continue reading

Do We Really Have Only 12 Years to Live?

By Andy May

Why have uninformed celebrities and politicians been telling everyone, who will listen, we are all going to die in a climate catastrophe in 10 to 30 years? U.N. General Assembly President María Fernanda Espinosa Garcés of Ecuador warned us that:

“We are the last generation that can prevent irreparable damages to our planet” (link)

Rep. Alexandria Ocasio-Cortez, once said:

we only have 12 years or “the world is going to end.” (link)

Figure 1. Rep. Alexandria Ocasio-Cortez (D-NY). Photo by Cheriss May of NurPhoto, taken on Feb. 5, 2019.

Continue reading