ENVIRONMENT / How Increases in Greenhouse Gases Cause Climate Change


The facts are that there is a substantial body of scientific evidence showing how increases in greenhouse gases are warming the planet and changing the climate. Let’s look at it.

Research measuring the the levels of CO2 trapped in the air pockets in ice core samples in both Antartica and Greenland show the relationship between CO2 levels and the temperature. Scientists have measured the these back to 800,000 years and shown that they track together. The higher the levels of CO2 the higher the temperature.

Radiative forcing

Greenhouse gases such as Carbon Dioxide increase the global temperature through a process called radiative forcing.

Radiative forcing is the amount of energy from sunlight that heats up our planet compared to the energy that escapes back into space. The atmosphere absorbs much of this energy. Without the atmosphere our temperature would be more like Mars. Earth would be a frozen planet.

Water vapor is the most important greenhouse gas in the atmosphere. It is responsible for keeping our planet warm instead of freezing and ensuring our temperatures are moderated.

Other greenhouse gases such as Carbon Dioxide, Methane and Nitrous Oxide trap heat through radiative forcing. This heat is measured in watts per square metre. Contrary to the disinformation of climate change deniers, the warming effect of greenhouse gases such as CO2 are measured and recorded.

The graph below shows the increasing warming effect of these gases in watts per square metre.

Water Vapor

Research from NASA’s Jet Propulsion Laboratory shows that as surface temperatures increases, so does atmospheric humidity.  The extra greenhouse gases in the atmosphere make the atmosphere more humid. Because water vapor is a greenhouse gas, the increase in humidity amplifies the warming caused by CO2 and other greenhouse gases.

The NASA researchers  found that if the Earth warms by one degree Celsius, the associated increase in water vapor will trap an extra two Watts of energy per square meter.

By adding up all of that extra energy over the entire Earth surface the researchers found that water vapor is trapping an enormous amount of energy  They found that the water vapor feedback is extraordinarily strong, capable of doubling the warming due to carbon dioxide.

Because the new precise observations agree with existing assessments of water vapor’s impact, researchers are more confident than ever that the increase in greenhouse gases will contribute to a temperature rise of several degrees by the end of the century.

Atmospheric CO2 levels have been increasing at two parts per million (ppm) per year. Despite the global economic shut down as a response to the COVID-19 pandemic CO2 levels still set a new record of 417.2 ppm in May 2020. This is a massive increase in emissions per year since the Paris Agreement and shows the reality is that most countries are not even close to meeting their Paris reduction commitments and many must be cheating on or ignoring their obligations.

Why is it so Important to Dramatically Reduce the Current Rate of CO2 Emissions?

If emissions are not reduced soon, we will be going into catastrophic climate change. This is because it will take centuries to get the heat out of our oceans. Ocean heat is a significant driver of our weather. The oceans and the atmosphere are already around one degree Celsius warmer than the industrial revolution.

The energy needed to heat the atmosphere and the ocean by one degree Celsius is equivalent to billions of atomic bombs. I am using this violent metaphor so that people can understand how much extra energy is being released into our atmosphere and oceans and why we will get more extreme weather events wreaking havoc on our communities and environment.

This extra energy is already violently fueling and disrupting our weather systems. It is causing weather events to be far more intense. Summer storms, especially cyclones, hurricanes, tornadoes, tropical lows etc. are far more intense with deluging and destructive winds, rainfall and floods. Winter storms are becoming colder and can be pushed further south and north than normal due to this energy, bringing damaging snowstorms and intense floods. Droughts and heat waves are more common and are resulting in more crop failures. They are also fueling destructive forest and grass fires that are burning out whole communities and destroying regional ecologies due to not allowing time for recovery before the next fires.

The frequency and intensity of these types of events will only get exponentially worse when the world warms to 2 degrees Celsius which is the upper limit of the Paris climate agreement. And we are on track to shoot way past this goal.

ABOUT THE AUTHOR / André Leu is the International Director of Regeneration International, a global NGO that promotes food, farming and land use systems that regenerate and stabilise eco systems, climate systems, the health of the planet and people. He, along with the other founders of Regeneration International, started the world wide regenerative farming movement. André is the Author of the ‘Myths of Safe Pesticides’ and ‘Poisoning our Children’. He is the co-author with Dr Vandana Shiva of ‘Biodiversity, Agroecology, Regenerative Organic Agriculture – Sustainable Solutions for Hunger, Poverty and Climate Change’ . André first came to the Douglas Shire in 1971 and has, with his wife Julia, an organic tropical fruit farm in Lower Daintree.

1 Comment
Oldest Most Voted
Inline Feedbacks
View all comments