Greenhouse Gases from human activities are the most significant driver of observed climate change since the mid-20th century.
A little history:
For most of the past 800,000 years—longer than human civilization has existed—the concentration of greenhouse gases in our atmosphere was between about 200 and 280 parts per million. (In other words, there were 200 to 280 molecules of the gases per million molecules of air.) But in the past century, that concentration has jumped to more than 400 parts per million, driven up by human activities such as burning fossil fuels and deforestation.
Identified by scientists as far back as 1896, the natural warming of the earth (that results when greenhouse gases in the atmosphere trap heat from the sun --that would otherwise escape into space) creates what is called the greenhouse effect. To quote from the NRDC, this is a good thing until it isn’t. It warms the planet to its comfortable average of 59 degrees Fahrenheit (15 degrees Celsius) and keeps life on earth, well, livable. Without it the world would be a frozen, uninhabitable place, more like Mars. The problem is, mankind’s voracious burning of fossil fuels for energy is artificially amping up the natural greenhouse effect.
How Does the Greenhouse Effect Work?
Sunlight makes the earth habitable. While 30% of the solar energy that reaches our world is reflected back to space, approximately 70% is absorbed by the land and the oceans (often called “carbon sinks”, with the rest being absorbed by the atmosphere, heating our planet. This heat is then radiated back up in the form of invisible infrared light. While some of this infrared light continues on into space, the vast majority—indeed, some 90% —gets absorbed by atmospheric gases, known as greenhouse gases, and redirected back toward the earth, causing further warming. This is what is often called “the greenhouse effect”.
The result? An increase in global warming that is altering the planet’s climate systems in countless ways.
Gases that contribute to the greenhouse effect:
Carbon dioxide (CO2) enters the atmosphere through burning fossil fuels (coal, natural gas, and oil), solid waste, trees and other biological materials, and also as a result of certain chemical reactions (e.g., manufacture of cement). About 76% of global human-caused emissions sticks around for quite a while. Once emitted, 40% still remains after 100 years, 20% after 1,000 years, and 10% as long as 10,000 years later.
Methane (CH4) is emitted during the production and transport of coal, natural gas, and oil as well as resulting from livestock , other agricultural practices, land use & decay of organic waste in municipal landfills).While super-polluting greenhouse gas emissions like methane don’t last in the atmosphere as long as CO2 (living decades rather than centuries), they do plenty of damage while they’re hanging around, accelerating the pace of global warming. A United Nations study issued in May, 2021 suggested that focusing on methane reductions from fossil fuels activities, landfills and agricultural production could help avoid almost 0.3 degrees Celsius of warming by the early 2040s.
Nitrous oxide (N20) is emitted during agricultural, land use, industrial activities, combustion of fossil fuels and solid waste, as well as during treatment of wastewater.
Chlorofluorocarbons (CFCs)are synthetic, powerful greenhouse gases that are emitted from a variety of industrial processes.
Water Vapor is the most abundant greenhouse gas increasing as the Earth’s atmosphere warms, but so does the possibility of clouds and precipitation.
Each of these gases can remain in the atmosphere for different amounts of time, ranging from a few years to thousands of years. They all remain long enough to become well mixed, meaning that the amount that is measured in the atmosphere is roughly the same all over the world, regardless of the source of the emissions.
Some gases are more effective than others at making the planet warmer and “thickening the Earth’s blanket.” The EPA has that covered as well.
The Consequences:
As greenhouse gas emissions from human activities increase, they build up in the atmosphere and warm the climate, pushing the planet into unprecedented territory, ravaging ecosystems, raising sea levels and exposing millions of people to new weather extremes, not to mention accelerating disease and extinction to all forms of life. At the current rate of emissions, the world will burn through its remaining “carbon budget” by 2030 — putting the ambitious goal of keeping warming to 1.5 degrees Celsius (2.7 degrees Fahrenheit) irrevocably out of reach.
What do the Scientists Say:
The latest IPCC report (4/4/2022) suggests that the world is running out of options to hit climate goals. Governments, businesses and individuals must summon the willpower to transform economies, embrace new habits and leave behind the age of fossil fuels — or face the catastrophic consequences of unchecked climate change.
What is the Federal Government Doing:
During the Trump administration, U.S. action around most super pollutants (with the exception of nitrogen oxide) came from states and cities, with the cooperation of some industry associations. That’s changing under the Biden administration, although even there, change has proven difficult, as demonstrated, for example, when the Build Back Better bill, the most sweeping climate bill in U.S. history collapsed after coal-state Sen. Joe Manchin III (D-W.Va.) pulled his support.
- In April of 2021, a bipartisan vote in the U.S. Senate reinstated an Obama-era regulation that requires oil and gas companies to monitor and repair methane leaks along pipelines, at storage facilities and in extraction operations (one of more than 100 environmental rules slashed by former President Trump).
- In April of 2021, the Department of Energy (DoE) committed $35 million for technologies to reduce methane, which it estimates contributes about 10 % of annual GHG emissions. The funding is focused on solutions for dealing with the exhaust from natural gas engines; rethinking the practice of flaring; and handling coal mine ventilation.
- In May of 2021, the U.S. Environmental Protection Agency also announced it is moving forward to phase down HFCs, mainly used for refrigerators and air conditioners. This measure, according to the EPA and the legislators supporting this action, would help to avoid 0.5 degrees of warming by 2100. The rule falls under the American Innovation and Manufacturing Act, a piece of bipartisan legislation adopted in late 2020 that provides “regulatory certainty” for decreasing the production and import of HFCs into the U.S. by 85 percent over the next 15 years.
- More than 100 countries have signed the Global Methane Pledge, which requires a 30% cut in methane emissions by 2030. In November of 2021, the Biden administration unveiled new rules to curb methane, from oil and gas operations.
- On April 23, 2022, Biden, at the Leader’s Summit on Climate. pledged to cut greenhouse gas emissions by 50-52% by 2030.
- Biden got some good news in May of 2022, when the Supreme Court allowed the administration to use a higher estimate for the societal cost of rising greenhouse gases as federal agencies draft regulations, turning aside a request from Republican-led states to prevent agencies from estimating the “social cost of carbon.”
Effects of the Coronavirus:
Based on preliminary data for 2021, Rhodium Group estimated, in January 2022, that economy-wide GHG emissions increased 6.2% in 2021 relative to 2020, though emissions remained 5% below 2019 levels. Current estimates put year-on-year GDP growth at 5.7%. indicating that GHG emissions rebounded slightly faster than the overall economy in 2021, largely due to a jump in coal-fired power generation, which increased 17% from 2020, and a rapid rebound in road transportation (primarily freight). As a result, progress in reducing US GHG emissions was reversed in 2021, moving from 22.2% below 2005 levels in 2020 to only 17.4% in 2021, putting the US even further off track from achieving its 2025 and 2030 climate targets. More on CCRs CORONAVIRUS page.
New Technologies?
What climate-tech superheroes hope to play a role in combating these super-pollutant villains? Look to our NEW TECHNOLOGIES page where the majority of explorations focus on carbon capture not reduction.
Some of these investments will no doubt be controversial with climate activists, who are likely to argue (legitimately) that they perpetuate natural gas extraction processes. There is no doubt, however, that regulating methane gas is critical for advancing President Joe Biden’s goal to slash U.S. emissions in half from 2005 levels over the next decade and achieve a net-zero economy by 2050.
Old Technologies
There is a great deal of discussion about importance of planting trees on land and kelp in the ocean to sequester carbon. More on that to be found on other pages: SEA TO SOIL, LAND & DEFORESTATION, and OCEAN AS CARBON SINK.
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