Global Warming paper introduction

[Lance Christie]

This is the introduction to my massive white paper on global warming.  The complete paper is being uploaded to the ManyOne Network steward for posting on either the Earth Restoration Portal < www.EarthRestorationPortal.org>, the Peaceful Uprising Portal < www.ManyOne.net/PeacefulUprising>, or possibly both (their call; they asked me for the paper to post):

GLOBAL WARMING: EVIDENCE AND IMPLICATIONS

by Richard Lance Christie
(Revised 14 Feb 09)

Introduction

Greenhouse gas molecules are necessary to life on earth.  Without the pre-industrial concentration of them in the atmosphere retaining about two-thirds of the solar energy striking the Earth’s surface, the Earth would have an average surface temperature of minus 4 degrees F.

Solar heat energy arrives as photons in a variety of wavelengths, including shorter-wave ultraviolet radiation and longer-wave infrared radiation on either side of the visible spectrum of light. As this energy passes through Earth’s atmosphere, some is reflected back into space by clouds and small particles such as sulfates; some is reflected by Earth’s surface, and some is absorbed into the atmosphere by substances such as soot, atmospheric ozone, and water vapor.  The remaining solar energy is absorbed by the Earth’s surface, warming it.  Energy re-radiated from the Earth’s surface stays in the atmosphere because it is reflected back towards the surface by clouds.  Re-radiated energy is also absorbed by atmospheric gases containing three or more atoms before it can escape into space: water vapor (H₂ O), carbon dioxide (CO₂ ), nitrous oxide (N₂ O), and methane (CH₄ ).  Heat energy is released by clouds as they condense water vapor into rain or snow.  Long-wave infrared radiation absorbed by these gases is re-emitted in all directions by these molecules, including back towards the Earth’s surface, and some of the re-radiated energy is captured by other atmospheric greenhouse gas molecules as well as by soil molecules.

Over the past half million years, the world’s climate has seen four ice ages and four warm periods in between them.  During the ice ages, extensive glaciers engulfed large swaths of North America, Europe, and Asia, displacing thousands of species.  During warm periods the ice retreated and the shapes of coastlines were rearranged as the seas rose from ice melt.  Yet throughout that period, the atmospheric concentration of CO₂ never rose above 300 parts per million.  These changes in ice coverage and climate in the northern hemisphere were due primarily to variations in earth’s orbit relative to the sun, causing solar thermal forcing per square meter to increase or decrease in the affected hemisphere.  Some cold events were due to sudden increases in global shading due to sulfur dioxide and particulates (ash) from volcanic eruptions in the atmosphere reducing the amount of solar radiation reaching the Earth’s surface.

Levels of both natural and un-natural gases which block infrared radiation from being reflected back out into space from the Earth’s surface have increased at an accelerating rate during the Industrial Age.  At the end of 2008, atmospheric concentration of CO₂ reached 387 parts per million (ppm); the previous high of 299 ppm was reached 325,000 years ago.  Atmospheric CO₂ level is now 35 percent above that in 1990.  Atmospheric levels of methane have increased 152 percent since 1750.  Total warming effect from all greenhouse gases in 2008 is equivalent to 430 ppm of CO₂ .  This predicts a 2.72 degree Celsius rise in mean global temperature from gases already in the atmosphere.

The last time greenhouse gas levels were this high was 3,500,000 years ago during the mid-Pliocene “warm period.”  They were higher in the Eocene, peaking 50,000,000 years ago, when crocodiles roamed Colorado and sea levels were 300 feet higher than today.  The difference in mean global temperature during the 15 million years the planet was ice-free in the Eocene versus 1750 A.D. was five degrees Celsius in the tropics and eight degrees Celsius in polar regions.

Up through February, 2007, the four Technical Assessment Reports of the International Panel on Climate Change (IPCC) produced a high estimate from their climate modeling of 7.1 degrees Fahrenheit mean global warming by 2100.  The 2007 IPCC Fourth Technical Assessment Report assessed all natural and human-caused sources of global radiative forcing and cooling.  A total of 2.65 watts per square meter of heat energy gain is due to gases put into the atmosphere by human activity.  A total of 0.12 w/m² of heat energy gain is due to increase of solar output since 1750 - this is what is causing melting of polar ice caps on Mars.  In short, 95.5 percent of global warming is due to human activity we can do something about, and 4.5 percent is due to natural causes we cannot affect.  Human activity has also produced a net -1.4 w/m² of global cooling due to aerosols in the atmosphere and albedo changes due to land use, for a net 1.81 w/m² of global warming effects from all causes.

In early 2007, the world climate scientist community discovered that the IPCC climate models had grossly under-predicted actual global warming when these predictions were checked against actual changes in polar region climate.  On March 6, 2007, the IPCC supplementary report, which corrected their climate models to include the positive feedback warming mechanisms observed in the polar regions, changed the median projection for global warming by 2100 to 7.2 degrees Fahrenheit, 0.1 degrees higher than the top of any previous estimate range.  Positive feedback warming mechanisms include release of methane from permafrost and methane hydrate deposits on the floors of polar oceans, changes in albedo (heat absorption) of polar regions due to reflective ice melting and being replaced by absorptive, dark open water and land, and warming oceans not being able to absorb as much CO₂ out of the atmosphere.

James Hansen and his collaborators looked back 65 million years to study the relationship between changes in atmospheric carbon dioxide levels and global climate.  Starting 60 million years ago and peaking 50 million years ago, CO₂ levels went to over 1,000 ppm when the carbon-rich Indian continental plate was rapidly subducted under the Himalayan.  The planet was ice-free for over 15 million years; by 34 million years ago, enough carbon was sequestered in oceans and carboniferous rocks that the Antarctic ice cap started to re-form.  The team determined that, for every degree Celsius of global warming from CO₂ , another degree Celsius of warming occurs from these secondary warming effects past a “trigger point” of 2 degrees Celsius warming relative to pre-industrial planetary climate, corresponding to 350 ppm of CO₂ in the atmosphere.

This led to the conclusion by James Hansen, Bill McKibben, Wendell Berry and others that we have to lower carbon dioxide in our atmosphere to 350 ppm to be safe from runaway global warming positive feedbacks.  This means that we must stop building new coal-fired sources of CO₂ emissions immediately, phase out sources of CO₂ emissions as rapidly as possible (Hansen says we have to stop burning coal by 2012), and pursue silvicultural, agricultural, and other practices that will accelerate the sequestration of CO₂ from the atmosphere.

As described in Plank One: Energy of the Renewable Deal < www.EarthRestorationPortal.org >, Best Available Technology and Best Available Management Practices are capable of replacing the current energy portfolio of the United States with a renewables-based energy system by 2050 that has no fossil fuel or nuclear inputs, emits no net greenhouse gases, produces more quads of energy than are estimated to be needed in 2050 under a no-conservation scenario at a slightly lower price in 2003 constant dollars than consumers paid for the current energy mix in 2003, and derives energy from sources that will not suffer depletion as long as the sun continues to fission.  Plank Two: Agriculture of the Renewable Deal describes contemporary agricultural and silvicultural practices which can both sequester about 60 percent more carbon than current practices, and will produce approximately 40 percent more calories per capita from the same agricultural land base as today.

The International Energy Agency’s World Energy Outlook 2008 report, November 2008, estimates that $26 trillion in 2007 constant dollars will have to be invested from 2007-2030 to finance exploration and implementation of new extraction technologies for fossil energy sources over these next two decades if remaining fossil fuel reserves are to be extracted to meet world energy demand.  Which is the better investment of $26 trillion: to develop dead-end carbon energy sources which will be fully depleted in a few decades at best, and which will cause massive disruption of the earth’s climate and therefore its economy if they are burned; or to develop the renewables-based energy portfolio the “fuel” for which is provided for free as long as the sun doesn’t burn out, emits no net greenhouse gases, and has far more available energy than our species can possibly develop and use under any consumption scenario?  Duh.