All you environmentalists? Give up and go home.

You will never get a handle on Carbon Dioxide (otherwise known as Plant Food).
From SciTech Daily:

Deadwood Releasing 10.9 Gigatons of Carbon Every Year – More Than All Fossil Fuel Emissions Combined
Decaying wood releases around 10.9 gigatons of carbon worldwide every year, according to a new study by an international team of scientists.

This is roughly equivalent to 115 percent of fossil fuel emissions.

Co-author of the study Professor David Lindenmayer from The Australian National University (ANU) says it’s the first time researchers have been able to quantify the contribution of deadwood to the global carbon cycle.

“Until now, little has been known about the role of dead trees,” Professor Lindenmayer said.

“We know living trees play a vital role in absorbing carbon dioxide from the atmosphere. But up until now, we didn’t know what happens when those trees decompose. It turns out, it has a massive impact.”

Yeah - photosynthesis takes in Sunlight, Water and CO2 and uses these to create the complex carbohydrates that the plants need to thrive.  When the plant dies, the left-over materials are recycled back to nature.  The CO2 is freed up for the next plant that needs it.  Earth once had CO2 over 9,000ppm - we are currently at 450ppm or thereabouts.