While the daily news that reaches us on the planet’s forests often talks about deforestation and the loss of habitat on our planet, a survey published in Nature’s climate change shows that the world has actually been greener over the past decade.
Despite unstoppable deforestation in South America and Southeast Asia, the decline in these regions has been offset by the recovery of forests outside the tropics and new growth in the drier savannas of Africa and Australia.
Plants take up about a quarter of the carbon dioxide that people release into the atmosphere by burning fossil fuels. More plants can mean more uptake of carbon dioxide. If so, it will slow down but not stop climate change.
However, questions remain about how long plants will be able to cope with our increasing emissions in a warmer climate.
Measurement of carbon in plants.
They have developed a new technique for mapping changes in plant biomass using satellite measurements of changes in radiofrequency radiation emitted from the Earth’s surface, a technique called microwave passive remote sensing. Radiation varies with temperature, soil moisture and water on plant biomass.
Vegetation information has been pulled from various satellites and merged into a time series of the past two decades. This allowed them to track global changes in biomass from month to month, which was not possible before.
In the period between the years 2003 and 2012, it was found that the total amount of vegetation on the planet increased by around 4 million tons of carbon. Still losing tropical forests, but gaining in forests elsewhere.
Global analysis shows vegetation loss in many regions, especially in South America and Southeast Asia.
Unsurprisingly, the largest declines were recorded in the vast Amazon forests. In Southeast Asia, we see the largest declines in the Indonesian provinces of Sumatra and Kalimantan – the Indonesian part of Borneo.
However, we find that these losses in the rainforest have been offset by increases in biomass in other parts of the world.
For example, forests spontaneously grew back on abandoned farmland after the fall of communism in Russia and its neighboring countries, while the projects of large-scale tree planting in China they added significant global biomass. This average more or less compensates for the loss of carbon due to tropical deforestation.
Likewise, an unexpected increase in vegetation has been observed in the savannas of Australia, Africa and South America.
On average, Australia is “greener” than it was two decades ago. This despite ongoing land clearing, urbanization and recent droughts in some parts of the country.
However, the increase in vegetation was not uniform. The largest increases are occurring in northern Australia, with minor increases in the south and a slight decrease in the southeast.
These trends seem to be explained mainly by rainfall patterns: the north of Australia received more water and the south-east was dry. This trend is expected to continue based on the most recent climate change projections from CSIRO and the Bureau of Meteorology.
Global vegetation plays an important role in the fight against climate change. About a quarter of all carbon emissions from human activities are removed by land vegetation.
However, it remains to be seen how the increased climate variability that accompanies climate change will affect the future. This is especially important for seasonally dry ecosystems that suffer from fires.
In general, the study provides evidence of the overall increase in vegetation.
But this is not enough, the terrestrial vegetation eliminates a quarter of the carbon emissions generated by humanity, the oceans of the world eliminate another quarter, this means that half of our CO2 emissions accumulate in the atmosphere. The reduction of fossil fuel emissions in the world is proposed as the only real alternative to fight against climate change and its consequences. Hopefully it is not too late.