Photosynthesis: Global rate is increasing due to rising CO2 levels

[ad_1]

An analysis of plants at 68 sites around the world finds evidence that rates of photosynthesis have risen since the year 2000



Environment



28 February 2022

European nature reserve

Photosynthetic rates have risen in recent years

Ryhor Bruyeu/Alamy Stock Photo

Since the early 2000s, the growing level of carbon dioxide in the atmosphere has led to an increased rate of photosynthesis around the world, climate scientists have found.

Plants produce energy through photosynthesis which takes in CO2 from the atmosphere or from water – a process known as primary production. The rate of this can increase in response to rising concentrations of the gas. This phenomenon is known as the CO2 fertilisation effect.

Now, Chi Chen at the University of California, Berkeley, and his colleagues have quantified the CO2 fertilisation effect globally for plants on land. The team collected data from 68 sites around the world – with croplands, grasslands and forests – that measured the changes in CO2 concentration in the air directly above the plants between 2001 and 2014.

Join us for a mind-blowing festival of ideas and experiences. New Scientist Live is going hybrid, with a live in-person event in Manchester, UK, that you can also enjoy from the comfort of your own home, from 12 to 14 March 2022. Find out more.

Across the sites, the rate of photosynthesis increased, with an extra 9.1 grams of carbon taken up per square metre per year since 2001. The team calculated that around 44 per cent of this increase can be attributed to enhanced CO2 levels in the atmosphere, while 28 per cent was down to rising temperatures.

The team then combined the data from these sites with satellite data and a global vegetation model to estimate the change over time worldwide. They found that global primary production increased, with an extra 4.4 grams of carbon taken up per square metre by plants every year since 2001.

The difference between the CO2 fertilisation effects at the sites and globally is due to a patchier global distribution of plants and the fact that vegetation regions will vary in productivity.

In recent decades, the total surface area of leaves around the world has increased. “This is largely due to this CO2 fertilisation,” says Chen.

“Plants under elevated CO2 are observed to be more efficient at using water, which often leads to faster growth as water is commonly a limiting resource,” says co-author Trevor Keenan, also at the University of California, Berkeley. “They may also grow faster and sequester more carbon, though other limitations such as nutrients can limit the extent to which increased photosynthesis translates to increased growth.”

However, negative effects of climate change may ultimately offset the CO2 fertilisation effect reported in the study. For example, more frequent and intense droughts due to climate change are adversely affecting plants globally, as are more frequent forest fires and insect outbreaks due to continued warming, says Keenan.

“Although plants are buying us time by taking up more CO2 in response to more CO2 in the atmosphere, it is not nearly enough to stop climate change,” says Keenan. “Reducing emissions is the only way we can prevent continued future warming.”

Journal reference: PNAS, DOI: 10.1073/pnas.2115627119

More on these topics:

[ad_2]

Source link

Advertisement

spot_img

How to convert a...

Whether you’re more comfortable working in PowerPoint or...

When To Stop Watering...

You can stop watering new grass seed daily...

Senate Preps for Hearings...

Washington —  On Monday, the U.S. Senate Judiciary Committee...

What DisplayPort’s new Ultra-High...

The Video Electronics Standards Association (VESA) has announced...

How to convert a Word document to a PowerPoint presentation

Whether you’re more comfortable working in PowerPoint or you’d like to present the content of your Word document in a different way, we’ve...

When To Stop Watering New Grass Seed 2022

You can stop watering new grass seed daily once it has germinated and the grass blades measure to about 1 inch. This should...

Senate Preps for Hearings on Biden’s Ground-Breaking Supreme Court Pick 

Washington —  On Monday, the U.S. Senate Judiciary Committee will begin four days of hearings on the nomination of Judge Ketanji Brown Jackson to...

What DisplayPort’s new Ultra-High Bit Rate (UHBR) certification means to you

The Video Electronics Standards Association (VESA) has announced a new DisplayPort certification called Ultra-High Bit Rate (UHBR) for DisplayPort 2.0. It establishes two...

Discover the best ways to earn passive income in 2022 with this $20 bundle

If you’re trying to get rich working for someone else, then the best of luck to you. From a practical sense, the only...