Carbon Dioxide and the rise of ‘super forests’
CO2. We live and breathe it. Plants absorb it and its accumulation in Earth’s atmosphere looms as one of the most prolific consequences of climate change in the 21st century.
Hold on! It may not spell disaster for us all just yet! Recent scientific breakthroughs in the field of ‘CO2 enrichment’ have unearthed some rather startling benefits of high CO2 for the world’s forests.
CO2 enriched ‘super forests’ may soon become a reality. Source: Pixabay
CO2 and plant growth
For plants, CO2 serves a vital input for growth courtesy of its role as an essential input into photosynthesis; the process by which plants convert energy from sunlight into chemical energy stored in sugar molecules called carbohydrates.
These energy-rich carbohydrates are utilised by plants to support new growth and in other metabolic processes that maintain the plant’s overall well being.
More CO2 = More photosynthesis
As one might expect, increasing the level of CO2 to which C3 plants are exposed has been successfully shown to accelerate the rate of photosynthesis. This principle is referred to as the ‘carbon fertilisation’ effect.
Essentially, this means the world’s forests are absorbing a proportion of the CO2 emissions we produce to fuel their growth and in doing so, are reducing the amount of CO2 that effectively remains in our atmosphere.
This is good news, right?
Well… sort of. As it turns out, there are a few key side effects *cringe!* of high CO2 on plant growth in C3 plants.
Three key effects of high CO2 on plants worth noting are:
- Increased growth rate
- Shorter lifespan
- Increased water efficiency (reduced transpiration/water loss)
As you might have guessed, the most crucial of these is the decrease in lifespan of plants because of their increased growth rate due to their increased uptake of CO2. It’s kind of like a ‘Benjamin Button‘ story of rapid-aging in reverse!
A recent scientific study conducted by ‘RAINFOR’ into the Amazon rainforest (a.k.a. the largest tropical rainforest in the world!), confirmed there is a persistent “long-term decreasing trend of carbon accumulation”. This is certainly an alarming thought considering the Amazon rainforest remains one of our planet’s largest ‘carbon sinks’!
Forests are doing us a huge favour, but we can’t rely on them to solve the carbon problem. – Professor Phillips, RAINFOR
What about the future?
One such way in which high CO2 levels on plants are currently being investigated is using ‘FACE’ or ‘Free Air CO2 Enrichment’ technology which describes a large mechanical ring that pumps enriched CO2 towards developing plants in the ring’s centre. This technique, among others, is providing scientists with crucial evidence to evaluate the future impact of high CO2 on plant growth.
The University of Birmingham’s investigation into FACE technology as a tool for future environmental risk evaluation.
Recent climate data from NASA’s Earth Science Division estimate the world’s forests are currently absorbing approximately 30% of the annual carbon dioxide produced through human activity. This is by no means sufficient to offset the surplus CO2 emissions that continue to accelerate global warming.
Thus, understanding the effects of high CO2 on plant growth is fast-becoming a vital tool in predicting how Earth’s vegetation will respond in the future to the high CO2 levels projected by current climate models of global warming.