“Communication works for those who work at it” – John Powell.

Dear Climate Healers,

In case you missed it, a recording of my dialogue with Dr. Will Tuttle, moderated by Clare Mann and hosted by The Vegan Community will be uploaded shortly on social media channels. Meanwhile, here is an expanded section of my speech addressing the questions that Dr. Will Tuttle and others have raised about mainstream climate science. We will be adding an FAQ section under the for-you tab on our web site, compiling these and other common questions and our responses to them.

CO₂ changes followed temperature in the ice core record. It is true that in the ancient ice core record, CO₂ often lagged behind temperature changes by several hundred years. But what it shows is that initial warming events, triggered by changes in Earth’s orbit and tilt known as the Milankovitch cycles, released CO₂ from oceans. That extra CO₂ then amplified the warming through the greenhouse effect. In other words, CO₂ was not the spark, but it was the fuel that turned small changes into major climate shifts. Today, we are lighting the fire ourselves by directly adding CO₂ at unprecedented rates.

CO₂ is plant food, not a greenhouse gas. It is true that plants need CO₂ to grow. But CO₂ is also, without question, a greenhouse gas. This is basic physics first demonstrated in the 19th century by John Tyndall and later quantified by Svante Arrhenius. The infrared radiation emitted by the Earth, as measured by satellites, has a distinct notch characteristic of the radiation profile of CO₂, as measured in laboratories (see figure). This makes it clear that more CO₂ traps more heat. Plants cannot absorb the vast excess of CO₂ we are emitting. Forests are being destroyed for animal agriculture, and oceans, which once absorbed much of our CO₂, are acidifying and losing capacity. Extra CO₂ may help plants grow in the short term, but it also fuels heatwaves, droughts, floods, and wildfires that devastate plant life in the long term.

Atmospheric CO₂ levels were much higher in the distant past. Indeed, there is fossil evidence that hundreds of millions of years ago, CO₂ levels were much higher. But the context matters. The Sun was dimmer then, ecosystems were radically different, tectonic plates were configured differently, and humans did not exist. Our entire civilization, our food systems, our shelter systems, our water systems, developed during the stable climate of the Holocene, when CO₂ levels were around 280 parts per million. Today, we have exceeded 425 ppm, a level not seen in millions of years. The problem is not that CO₂ was once higher; it is that our civilization depends on the stable climate we are now destabilizing, while life on Earth is visibly unable to adapt to the rate at which we are destabilizing it.

CO₂ is a tiny fraction of the atmosphere and cannot affect climate. CO₂ is indeed a tiny fraction of the composition of the atmosphere. At 425 parts per million, on average, the atmosphere contains 425 CO₂ molecules in every 1 million molecules. But that doesn’t mean these molecules are not capable of trapping heat in the atmosphere and having an impact on the Earth’s climate. Just a spoonful of arsenic has a major impact on our well-being even if we are consuming it with a plateful of edible food.

Humans are emitting a very small portion of the CO₂ compared to Nature. Yes, the natural carbon cycle involves an order of magnitude more CO₂ than that emitted by deforestation, fossil fuel burning and other human activities. However, the natural carbon cycle is balanced: there is just as much CO₂ absorption through photosynthesis as CO₂ emitted through respiration. Human activities are currently disturbing this natural balance and Nature is unable to increase photosynthesis in order to compensate for our additional emissions. This is causing the CO₂ levels in the atmosphere to increase year by year.

Water vapor is a more powerful greenhouse gas than CO₂. Water vapor can heat or cool the Earth’s climate depending on its state. Water vapor has a radiation profile in the infrared region and can form dark clouds that absorb infrared radiation as well. Therefore, water vapor can heat the climate. Water vapor can also form white clouds that reflect visible light and therefore, cool the climate by reflecting some of the incoming solar energy back into space. However, water vapor is generally short lived in the atmosphere since it comes down in the next rain. Therefore, it amplifies the impact of other emitted gases such as CO₂ and SO₂. Since CO₂ has its radiation profile in the infrared region of the electromagnetic spectrum, it reflects the Earth’s black body radiation down, which stimulates more water to evaporate from water bodies. SO₂ combines with water molecules to form bright sulfuric acid fumes, which reflect the sun’s energy back into space and therefore, cools the climate. This is how water vapor amplifies the heating and cooling impact of other gases.

Climate is too complex and models are useless. All models are an approximation of reality, but that doesn’t mean they are useless. In Nature, every leaf, every rock, every grain of sand is unique. Models attempt to capture aggregate behavior in Nature and they have been successfully used to predict and design the world that we live in. The UN IPCC compiles results from a range of climate models. All climate models are calibrated with historical and measured data from earth observatories and then used to predict future climate trends.

Climate models are characterized by their CO2 doubling sensitivities, which is the increase in the equilibrium surface temperature of the Earth if its atmospheric CO2 concentration is doubled, while holding all other parameters constant. The average IPCC climate model uses 3.0°C as the CO2 doubling sensitivity. When someone states that CO2 is not a greenhouse gas, they are arguing for 0°C as the CO2 doubling sensitivity, but there is no such climate model that has been calibrated with historical and measured data from Earth observatories. In contrast, Dr. Jim Hansen and his colleagues have made a credible case that the CO2 doubling sensitivity of the Earth is actually around 4.5°C in order to explain anomalies in the measurement data for 2023 and 2024.

The science is not settled on climate change. Science is never settled on anything since the scientific method is not about asserting the truth, but about discovering and discarding untruths. However, science tries to explain natural phenomena through matching a theory with observations and slowly builds up a mountain of evidence for the validity of that particular theory. In that respect, mainstream climate science has a solid footing that may, in future, be dislodged with a credible alternate theory that matches better with observational data. The proffered alternatives don’t yet fit that description.

In summary, the science on climate change is persuasive. CO₂ is both a plant nutrient and a powerful greenhouse gas. Besides, CO2 is just one among a dozen human-caused emissions and factors that impact the Earth’s climate. And humans are destabilizing the Earth’s climate now, in ways that are undeniable and dangerous.

Join us at V-COP23

Please join us in Toronto for the Vegan Convergence Of the Peoples #23 (V-COP23) on Nov 1-2 to help shape and implement our system design plan for Planet B. The theme for V-COP23 is offered by our co-host, Plant Based Treaty: Redirect, Relinquish, Restore::

Redirect our focus from fixing Planet A to building Planet B.
Relinquish the excess resources we have taken from the planet.
Restore the life-support systems of the planet with the relinquished resources.

Please be there and help make history.

With much love,