Do humans harm the environment?

By Andy May

This is the first of seven posts on the potential costs and hazards of human-caused global warming and the impact of humans on the environment in general. The IPCC WGII AR5 Technical Summary, defines “hazards” 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.”

Do humans harm the environment? If we assume humans are causing most of the current global warming, is the warming dangerous? If we are dangerous to the environment, should we limit our population in some way? If global warming is potentially dangerous, and we assume human CO2 emissions are the cause, would we be better off to adapt to the human-caused global warming and continue using fossil fuels, or do we need to stop using fossil fuels to limit emissions? We will consider these issues here and in future posts. Continue reading

Calculating the Cost of Global Warming

By Andy May

Hopefully, the first two posts in this series, “Do humans harm the environment” and “Population Growth and the Food Supply” have convinced the reader that man-made climate change and global warming are not an existential threat to humanity or the planet. This leaves us in a discussion of the cost of global warming, which is something we can calculate. To do the calculation, we need to estimate the monetary damages caused by global warming, when they will be incurred, and the discount rate of money over that period of time. We will not attempt the calculation here, it is too complex, but we can discuss the parameters and some of the calculations done by others. 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

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

By Andy May

It’s more likely mostly due to both, but that isn’t really the question. Virtually everyone accepts that climate changes and that CO2 and methane are greenhouse gases; and probably everyone remembers from grade school that the Sun is a variable star. The debate is over how much of recent global warming is due to the Sun, either its internal variability or changes in the Earth’s orbit, and how much is due to human greenhouse gas emissions, mostly from fossil fuels? Continue reading

Defending Scott Pruitt – Making science reproducible

By Andy May

The EPA secretary, Scott Pruitt, testified before the House of Representatives Energy and Commerce Committee on Thursday April 26, 2018. He had been charged with spending too much money on travel, security and a secure phone booth for his office. Certainly, a reason to reprimand him, but I’m not sure a full day of Congressional hearings were warranted. Besides Scott Pruitt has spent far less on travel than either of his immediate predecessors at the EPA. Continue reading

Global Climate Models

By Andy May

Global Climate Models (GCM) are used to compute the social cost of carbon dioxide emissions and to compute man’s contribution to recent global warming. The assertion that most of “climate change” is due to man’s influence is based solely on these models. They are also the sole basis for concluding “climate change” is dangerous. Just how accurate are they? How close are their predictions to observations?

Dr. Judith Curry has written an important white paper, for the layman, describing how the models work. It is easy to understand and well worth reading.

Her key conclusions:

GCMs have not been subject to the rigorous verification and validation that is the norm for engineering and regulatory science.

There are numerous arguments supporting the conclusion that climate models are not fit for the purpose of identifying with high confidence the proportion of the 20th century warming that was human-caused as opposed to natural.

There is growing evidence that climate models predict too much warming from increased atmospheric carbon dioxide.

Some portions of the GCMs are rooted in fundamental physics and chemistry, but there are thousands of atmospheric and surface processes that cannot be deterministically modeled and must be “parameterized” using simple empirical formulas based on observations. These empirical formulas are “tuned” or “calibrated” to make the models match observations. They are tweaked to match the twentieth century, especially the warming period from 1945 to 2000. Even with all of the tuning, the models do a very poor job matching the warming from 1910-1945.

Since all models are “tuned” to the twentieth century (see Voosen, et al., Science, 2016) and since the “more than half of warming is due to man” conclusion is based upon comparing two model runs “from 1951 to 2010” the validity of the computation of man’s influence is highly questionable. Dr. Curry points out:

“GCMs are evaluated against the same observations used for model tuning.”

This is not something that inspires confidence. Further, the Earth has been warming for 300 to 400 years, as Dr. Curry writes:

“Understanding and explaining the climate variability over the past 400 years, prior to 1950, has received far too little attention. Without this understanding, we should place little confidence in the IPCC’s explanations of warming since 1950.”

She adds:

“Anthropogenic (human-caused) climate change is a theory in which the basic mechanism is well understood, but of which the potential magnitude is highly uncertain.”

Precisely so.

On the new EPA Carbon Dioxide emission rule for power plants on

This is a comment I put on about the proposed new rule.

The key assumption in this rule is that man-made Carbon Dioxide is harmful to the environment by altering our climate. I do not think this is proven. The key elements of the debate on man-made catastrophic climate change are actually pretty simple. Obviously, climate changes and it is warmer than it was 150 years ago, so these facts are not in dispute. It is the “man-made” and the supposed impending catastrophe that are controversial.

Now, if we were to double the amount of CO2 in the atmosphere from the current 400 PPM (0.04%) to 800 PPM physics and chemistry would predict that the atmospheric temperature would increase a trivial 0.75 degrees C. The climate alarmists have used global circulation models (GCM’s) with a climate sensitivity factor that increases this to three or four degrees C by assuming positive feedbacks. These models generally assume that as CO2 goes up, water vapor will increase and since water vapor is a much stronger greenhouse gas than CO2 they speculate that temperature will spiral out of control with catastrophic effects. That is pretty much their case.

The problems with this are twofold. First there are no measurements to support the idea that water vapor will increase with CO2. In fact, the models suggest the highest rate of warming should be in the tropics because most water vapor is there and most heat enters the atmosphere there. But no significant warming has occurred in the tropics (or in Antarctica for that matter), warming has been almost entirely in the northern Northern Hemisphere and especially in the Arctic. Further, if more water is held in the atmosphere wouldn’t we get more clouds? Will the clouds make us warmer or cooler? No one knows, clouds are not in the GCM’s. Second, the GCM’s have not been successful in predicting anything yet. Observations have shown no increase in global temperature since 1998, but the models predicted an increase. The proportion of CO2 in the atmosphere has increased, why no increase in temperature?

We need to remember that man’s burning of fossil fuels contributes only 8% of the CO2 that goes into the atmosphere; respiration, microbial activity, volcanism, ocean outgassing, etc. provide the rest. We also need to remember that the average CO2 in the atmosphere after the dinosaurs and until the ice age (which we are still in) is 800 ppm. Atmospheric CO2 only decreased to 300 PPM (and perhaps less) due to the ice age. The article noted below provides actual evidence (not a computer model) that the additional climate sensitivity due to doubling CO2 to 800 ppm will increase the average temperature 1.093 degrees C. A trivial amount and a fraction of what the IPCC circulation models predict. This makes much more sense and is in line with what has been seen in the Earth’s history. If this article stands the test of time, it kills the entire alarmist argument. Some have said that computing or measuring climate sensitivity to CO2 is a fool’s errand and perhaps this is so. But, either way the alarmist argument is destroyed. It is far from certain that climate change is a problem or even unusual.

Other references (Princeton Professor William Happer and MIT Professor Richard Lindzen):!B951E1BE-01A3-4F92-B871-A4AB9B171419

Dr. Roy Spencer

McKitrick and Vogelsang, 2014

#climate-change, #climate-sensitivity, #global-circulation-models