Politicians Unclear

Yes, this isn’t likely to go away soon. History motivates this conclusion:

All right. That just about unraveled all the good sense that went before. Senate Majority Leader Norris reminds us, “I hear Satan snickering. He loves this kind of mischief.” Ignoring completely what is well known, that Satan is a mythical character. Can we surmise Senator Norris thinks The Great Pumpkin will be snickering, as well?

What is it about otherwise intelligent people that bubbles the stupid to the top the moment they get the hots for public office. Do they feel the need to plumb the depths of the electorate gene pool? Possibly.

Then, who’s the candidate of the day? That would be Jeb Bush, son of a famous U.S. President and brother of another. And Mr. Bush said what?

“Look, first of all, the climate is changing. I don’t think the science is clear what percentage is man-made and what percentage is natural. It’s convoluted. And for the people to say the science is decided on, this is just really arrogant, to be honest with you,” he said.

“It’s this intellectual arrogance that now you can’t even have a conversation about it. The climate is changing, and we need to adapt to that reality,” he said.

The first thing I pick up from this is that Mr. Bush’s reading list must be short. His statement, “I don’t think the science is clear what percentage is man-made and what percentage is natural,” indicates he missed a few issues of Science, Nature or even Popular Mechanics. For the record, here is the measured concentration of CO₂ in the atmosphere since 1960.

The CO₂ concentration has been steadily rising. The only thing contributing to this rise is human activity. Natural fluctuations cannot account for this pattern. The small ripples in this curve are due to seasonal growth in the Northern Hemisphere, where most plant growth exists. No volcanic eruptions and other natural fluctuations exceed this seasonal variation.

This plot is named the Keeling Curve, after Charles David Keeling, who initiated these measurements in 1959. Compare this to the deep history of CO₂ levels:

Over the past 400,000 years, CO₂ concentrations have varied regularly from about 180 parts per million during the deep glaciations of the Holocene and Pleistocene to 280 parts per million during the interglacial periods. Following the start of theIndustrial Revolution, atmospheric CO₂ concentration has increased to 400 parts per million and continues to increase. This has caused the phenomenon of global warming which is mostly attributed to human CO₂ emissions

CO₂ concentration has not been at present levels in the past 400,000 years.

Now look at the effect of greenhouse gases on atmosphere and ocean temperatures.

This diagram can benefit from some elaboration. Here is a dissection of the part showing the consequences of radiation from the sun entering the atmosphere and being absorbed. Some (67 Watts per square meter) never reaches the surface. It is absorbed by the atmosphere. The remainder (168) is absorbed by the surface (land or water). This does not include the radiation that is not absorbed as it comes from the sun.

This shows energy radiated into space. 195 Watts per square meter is radiated from the atmosphere into space. The remainder is radiated from the surface and is not absorbed by the atmosphere.

This shows how the greenhouse effect recirculates energy back into the atmosphere after it has been absorbed by the surface. Note that only a small fraction of the radiation from the sun is in the infra red spectrum. Greenhouse gases absorb the infra red. They are mostly transparent to visible light, the bulk of energy from the sun.

Visible light that is absorbed by the surface mostly goes into heat energy, which warms the surface. The surface temperature of the Earth is on average 15 C. At this temperature a body of matter (idealized as a “black body”) will not radiate in the visible spectrum, but it will radiate in the infra red. See the following illustration:

37 C is the temperature of a human body. Visible light has a wavelength in the range 390 to 700 nm (nanometers). That’s off the chart to the left. Objects about the temperature of the Earth’s surface radiate copiously in the infra red spectrum, and that is where greenhouse gases absorb.

What are the consequences? Here is another diagram.

As expected, with the increase in CO₂ concentration in the atmosphere, the land-ocean temperature averages are increasing. No other explanation for this rise has been proposed other than human contribution to greenhouse gases in the atmosphere.

Mr. Bush’s statement that, “I don’t think the science is clear what percentage is man-made and what percentage is natural,” is at best naive, bordering on stupid and at worst dishonest. Most damning is his statement, “It’s this intellectual arrogance that now you can’t even have a conversation about it. The climate is changing, and we need to adapt to that reality.” Yes, the climate is changing. Yes we are going to have to adapt. To lay off the cause to other than human activity is disreputable to the core. Our nation deserves better.