Sunday, June 29, 2008

Climate and climate change: Envoi

And so we come to the end of the road we began 19 months ago. We've covered almost every aspect of Earth's climate, climate change, the "global warming" craze, basic physics, the nature of scientific theories and science as a culture, and the associated politics, policy, and journalism. Some points were only touched on, others explored at great length, with some tangents here and there. Friends tell me I need to turn the whole production into a book, and maybe I will one day.

On the blog, we'll continue to comment from time to time about climate trends, political trends, and related economic questions, which we haven't talked about much. This blog now has a significant list of climate-related posting labels that you can use to locate postings on particular topics. They include: climate, environment, geoengineering, global warming, polar, radiation, storms, thermodynamics. Some additional technical topics include: chaos, cycles, Fourier, statistics. And don't forget the excellent climate blogs to the right: ClimateAudit, CO2 Science, and World Climate Report.

The one-minute summary. Start with the Earth, its atmosphere and oceans, add the Sun and its heliosphere (solar wind and magnetic field). Add the most distinctive thing about Earth's climate, the presence of water and its astonishing repertory of possibilities. Radiation comes in from the Sun and is absorbed and re-radiated as infrared (IR) at a temperature of about 288 oK (56 oF = 15 oC). Carefully distinguish heat (some "thing" in a volume) from heat flow (some "thing" moving in some direction, with some magnitude). From the thermal point of view, the Earth is an open system; heat doesn't stop, but keeps flowing out, balancing what flows in. It's how it flows that determines the distribution of temperature and humidity.

Radiation (moving at the speed of light)
heat = heat flow

Matter (moving much more slowly): earth, water, air
heat ≠ heat flow

In matter, heat can:
  • Flow through (conduction)
  • Move with (convection)
  • Transform phase (water)
The phases of water are:

Vapor ++evaporation/condensation++ Liquid ++melting/freezing++ Crystal (Ice) ++sublimation/deposition++ Vapor etc. *

From the mechanical and chemical points of view, OTOH, the Earth system is closed, if we draw the boundaries properly and include oceans, crust, air, and living things.

Heat flows upward through the atmosphere and, as radiation, back into space, determining its temperature, humidity, and cloud distribution by a mix of three types of flow: infrared-radiative, evaporation, and convection. The flow is not radiation alone, and the Earth's atmosphere is not a greenhouse, not even approximately.

Radiation is a steady flow, although it is strongly affected by clouds. Heat convection, an aspect of fluid turbulence, is chaotic and makes weather unpredictable beyond about two weeks ahead. On longer times, the weather exhibits fundamentally nonrepetitive patterns, in spite of the many aspects that do repeat. Atmospheric fluid turbulence is additionally complicated by the ceaseless transformations of water: liquid to vapor to condensed droplets (clouds) to heavier, falling droplets or crystals (precipitation), back to liquid or ice again. Fluid turbulence remains the hardest unsolved problem in physics. But not capturing the full nature and effect of clouds is probably the single largest failing in contemporary climate models.

Global warming as barely noticeable. The presence of IR-opaque gases in the clear air (water vapor, carbon dioxide, methane) directly modifies the outflow of radiation and indirectly modifies air and water temperatures, evaporation, clouds, precipitation, and convection. A "globally-warming" world would be one that looks a little more tropical, with the largest relative changes happening in the coldest regions (the poles) and during the coldest times (the winter). There's no evidence that this pattern is under way. The time scale is not decades, but a couple centuries, and on that scale and longer, plant and ocean absorption of carbon dioxide will have a major impact. It's very unlikely that a doubling of carbon dioxide concentration would have much of an effect, except perhaps for enhanced precipitation. A tripling would, but plant and ocean absorption might prevent that from ever happening.

Beyond doing nothing, the only justifiable countermeasure at this time is the easy and benign one of more and better plants, with CO2 emission taxes held in reserve in case of the problem is worse than foreseeable now. Scrap everything else, including cap-and-trade. Ignore Stern, Gore, and the other sanctimonious doom-preachers with wild, costly schemes.

I've never met anyone who hates trees, and there are plenty of places in the world that could use more of them.

Environmentalism, politics, and policy: My two cents. Another approach to the profoundly non-crisis nature of "global warming" is to take the cost and benefit estimates of a previous posting (Nordhaus), combined with the 2.5 kg of CO2 gas emitted for every gallon of gasoline burned. The estimated "global warming" cost (with the IPCC's too-high numbers) is about $8/metric ton CO2. A tax offsetting the cost would then be roughly (0.0025 metric tons CO2/gallon gasoline)*($8/metric ton CO2) = $0.022, or 2 cents per gallon. With a scaled-down estimate of the cost of "do nothing about CO2 emissions," we're below a cent per gallon.

Of course, you might say that such a cheap tax should not be objectionable, and, in a limited sense, you're right. If such a tax ever becomes necessary, our politicians would probably squander the revenue on some stupidity or other. But there's only one right place the money should go: to more trees and other plants. But that misses my larger point, which is the utter triviality of the issue compared to other, much larger, and far more pressing issues.

"Environment" and "energy production" are often lumped together, but they shouldn't be. Our economic and geopolitical need for a change to energy production (especially toward biofuels and nuclear power) is a real problem, right now, that needs addressing in the next few years, not the next couple centuries. The path forward is blocked partly by stupid and obsolete regulation. Pollution of the old-fashioned kind has not been much of a problem in wealthy countries for more than a generation. It is a major problem in "middle-income" countries undergoing rapid development, like China, Brazil, India, and Russia. Gases like carbon dioxide, methane, and water vapor are not exotic poisons from Planet Krypton; they're gases the Earth's oceans and plants have been processing for billions of years.

While I'm optimistic about the power of reason on such issues in the longer term, and especially on ordinary voters, I'm much less sanguine about our decadent political class (politicians, media, environmentalists), with their heavy investment in bad theories, misinformation, and guilt trips. Their unquenchable addiction to pseudo-apocalypses and pseudo-messiahs has become an active danger to our future. At the same time, they ignore real problems, especially ones they helped to create. The scientific case for "climate change" apocalypse, never strong, has disintegrated. The blind juggernaut of bad politics, bad journalism, and hollow Official Science rolls on. It's up to us to shut it down.
* The atmospheric pressure is too high on Earth for ice to sublime directly from ice to vapor. But not on low-pressure Mars.

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