Patrick Moore is a founding member and past president of Greenpeace, but he no longer supports the organisation because it’s turned into a politically correct mess.
He is also the author of a few books that aggressively take on climate change propaganda.
For example, in Fake Invisible Catastrophes and Threats of Doom, he argues that most environmental fear porn is based on what we can't see, like carbon dioxide (CO₂) and polar bears, leading people to believe alarmist nonsense.

CO₂ lives matter
Carbon dioxide is critical for all life on Earth. More of it equals more life. Less of it equals less life.
As we learnt in school, it is a crucial component in the process of photosynthesis, which allows plants to convert sunlight, water and CO₂ into energy-rich carbohydrates. Higher levels of CO₂ enhance this process, leading to increased plant growth.
More CO₂ means more food.
The controlled use of CO₂ in greenhouses is a well-established practice in agriculture. By introducing elevated levels of CO₂ in greenhouses, farmers optimise and increase plant growth.

NASA’s own satellite data has shown an increase in Earth’s green vegetation cover, often referred to as 'Earth greening.' This greening effect is attributed to higher levels of atmospheric CO₂.
There is no reason to reduce CO2 levels.