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“We are the first generation to feel the sting of climate change, and we are the last generation that can do something about it.” — Jay Inslee
The earth’s climate has cycled through glacial periods eight times in the last 800,000 years. The ice ages average 100,000 years followed by an interglacial period of 10 to 15,000 years. These cycles are primarily influenced by changes in the earth’s orbit and inclination, affecting the amount and distribution of solar radiation reaching the planet.
The interglacial period preceding the one we live in, named the Eemian Epoch, lasted 15,000 years. Global temperatures were 1.8 to 3.6 degrees Fahrenheit warmer than our pre-industrial temperatures and sea levels were 20 to 30 feet higher.
The last ice age began 115,000 years ago, lasting 103,000 years. It peaked 20,000 years ago, after which warming began. During its peak, 30% of the earth’s water was held as ice and sea levels were 400 feet lower than today. Amazingly, average global temperatures were only 11 degrees cooler than the pre-industrial average. The Western Washington glacier, which had reached its southernmost point near today’s city of Tenino, began retreating northwards 16,850 years ago.
The warming trend was interrupted 12,900 years ago by the Younger Dryas event, which very rapidly pushed the earth back into the ice age with average temperatures over Canada and Greenland plummeting up to 18 degrees. This event is blamed for the extinction of many species and the demise of the Clovis people. It’s interesting to scientists because it demonstrates how earth’s climate can change suddenly and disastrously.
Twelve-hundred years later, the earth warmed rapidly, bringing us into the Holocene Epoch. Although humans migrated from Africa during the last ice age and spread throughout the world, all recorded human history has been during this short period.
All life on our planet, including we humans, live at the bottom of an atmospheric ocean. This ocean of gasses has five boundary levels. The primary gasses are nitrogen at 78% and oxygen at 21%. Our main environment is the troposphere, extending about 6 miles above us here in Washington state. The troposphere contains 75% of our planet’s atmospheric mass and 99% of the mass of total water vapor and aerosols. Most weather phenomena occur in the Troposphere.
The next atmospheric level is the stratosphere. When your passenger aircraft reaches cruise altitude, you are in the stratosphere. The life-protecting ozone layer, which was being destroyed by refrigerant gasses, is in the stratosphere, above where your jet aircraft flies.
Our atmospheric ocean provides oxygen, regulates temperature and shields us from meteors and cosmic rays. The atmosphere also interacts with the oceans, the land and the biosphere, forming a complex and dynamic system that influences the climate and environment. The atmosphere is constantly changing due to natural and human factors, such as solar activity, volcanic eruptions, greenhouse gas emissions and pollution.
Sun, earth, sky, ocean, forest and biological life all cycle in a sacred balance. Water continually cycles between ocean and sky. So does carbon. Water, as vapor, and carbon, as carbon dioxide (CO2), trap heat from our sun in the atmosphere. The atmosphere can only hold so much water as gas and continually returns the excess to earth. Not so with carbon. The atmosphere can hold an unlimited amount of excess carbon bonded with oxygen, as carbon dioxide gas, with the earth and ocean only reclaiming as much as they can process and absorb.
Over the last 800,000 years, global temperatures have shown a direct correlation with atmospheric CO2 levels. Approximately 385 billion tons of CO2 are produced each year from natural sources and a near equal amount is eliminated in a natural process of carbon sequestration in the earth and ocean. When the trend is for less CO2 produced than sequestered, the earth cools. When more is produced than sequestered, the earth warms.
Atmospheric CO2 levels had been less than 300 parts per million (ppm) for the last 3 million years. During the Eemian epoch, levels were 280 ppm, and 260 to 280 ppm during the current Holocene epoch, before the Industrial Era. CO2 levels began rising around the year 1800 and broke the 300 ppm level in 1910. Since World War II, CO2 levels have been rising exponentially, reaching an alarming 428 ppm at present.
With CO2 at pre-industrial levels of 280 ppm, the atmosphere held 1.45 trillion tons of heat-trapping CO2. At the current 428 level, there are 2.73 trillion tons in the atmosphere and humans are contributing over 44 billion tons annually. At the same time, human activity of deforestation, ocean pollution and other actions are reducing the world’s natural carbon sinks.
The United Nations Intergovernmental Panel on Climate Change (IPPC) in their latest Summary for Policymakers report stated: “Human activities, principally through emissions of greenhouse gasses, have unequivocally caused global warming, with global surface temperature reaching 1.1 degrees celsius above 1850-1900 in 2011-2020. Global greenhouse gas emissions have continued to increase, with unequal historical and ongoing contributions arising from unsustainable energy use, land use and land-use change, lifestyles and patterns of consumption and production across regions, between and within countries, and among individuals.”
The IPPC 2022 report cites the many negative consequences already affecting the world, as well as multitudes of future severe consequences related to rapid global warming.
The Future Climate Change section begins: “Continued greenhouse gas emissions will lead to increasing global warming, with the best estimate of reaching 1.5 degrees celsius in the near term in considered scenarios and modeled pathways. Every increment of global warming will intensify multiple and concurrent hazards. Deep, rapid and sustained reductions in greenhouse gas emissions would lead to a discernible slowdown in global warming within around two decades, and also to discernible changes in atmospheric composition within a few years.”
The 1.5 degrees celsius maximum global temperature increase was reached in 2023.
In the next segment, I will explore the international climate mitigation goals, timelines and how likely it is that the world will even come close to meeting them. What are the “green energy” alternatives, their feasibility and limitations? There will be a slow, painful and expensive retreat from cheap and plentiful carbon-based fuels. Can the demand be met?
Find the IPPC info and report online at https://www.ipcc.ch/report/ar6/wg2/.
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Bill Serrahn, who lives in Packwood, has written several climate-focused commentaries for The Chronicle. They can be found at chronline.com.
