What kind of pollution do you want to feed your plants? The carbon kind.
Yet again, a satellite study of leaf area shows that the world is greener than it was in 1982. There are more plants mostly thanks to CO2 aerial fertilization. The biggest benefits from CO2 are in the warm tropics. The extra greenery in colder areas was due to that other disaster called “global warming”. About a tenth of the greening had nothing to do with either carbon pollution or extra warmth and was apparently thanks to nitrogen from man-made fertilizers.
Obviously we need a $10 billion dollar program to stop this immediately.
Click to enlarge.
Humans are Greening planet Earth — ABC
The most comprehensive modelling of remote sensing data so far shows the area on Earth covered by plants in this time has increased by 18 million square kilometres — about 2.5 times the size of the Australian continent — largely due to the fertilising effect of carbon dioxide (CO2).
“[The greening] has the ability to fundamentally change the cycling of water and carbon in the climate system,” said Dr Zaichun Zhu, from Peking University in China and lead author of the new study, which appears today in the journal Nature Climate Change.
Drs Zhu, Canadell and colleagues found that the 46 parts per million increase in atmospheric CO2 between 1982 and 2009 was responsible for 50 to 70 per cent of the observed greening.
“Carbon fertilisation is the dominant process for greening across the globe, particularly in the tropics because there’s so much leaf area there,” Dr Canadell said.
The new study found other causes of the greening, including nitrogen from agricultural fertilisers.
As I keep saying: burn fossil fuels and feed the world.
Plants are so dependent on CO2 that they suck out half the CO2 out of the air before lunchtime each day.
ABSTRACT
Global environmental change is rapidly altering the dynamics of terrestrial vegetation, with consequences for the functioning of the Earth system and provision of ecosystem services1, 2. Yet how global vegetation is responding to the changing environment is not well established. Here we use three long-term satellite leaf area index (LAI) records and ten global ecosystem models to investigate four key drivers of LAI trends during 1982–2009. We show a persistent and widespread increase of growing season integrated LAI (greening) over 25% to 50% of the global vegetated area, whereas less than 4% of the globe shows decreasing LAI (browning). Factorial simulations with multiple global ecosystem models suggest that CO2 fertilization effects explain 70% of the observed greening trend, followed by nitrogen deposition (9%), climate change (8%) and land cover change (LCC) (4%). CO2 fertilization effects explain most of the greening trends in the tropics, whereas climate change resulted in greening of the high latitudes and the Tibetan Plateau. LCC contributed most to the regional greening observed in southeast China and the eastern United States. The regional effects of unexplained factors suggest that the next generation of ecosystem models will need to explore the impacts of forest demography, differences in regional management intensities for cropland and pastures, and other emerging productivity constraints such as phosphorus availability.
This study appears to show a reduction in leaf area across a lot of Western Australia which is rather at odds with most other studies that show that arid dry areas are exactly the ones that benefit most from CO2 enrichment, since the extra CO2 helps plants cope with droughts. I don’t know why this study shows the opposite effect in WA. Nor do I know why they say that global vegetation’s response is “not well established” when skeptical scientists have been predicting this for decades and past studies also showed plants grow faster, and there are increases in Net Primary Productivity and biomass in many locations.
h/t OriginalSteve, Bulldust, handjive.
REFERENCE
Zaichun Zhu, et al (2016) Greening of the Earth and its drivers, Nature Climate Change, Letter, doi:10.1038/nclimate3004