From UPSC perspective, the following things are important :
Prelims level : Not Much
Mains level : Reforestation and its role as carbon sink
Forests as CO2 sink
- Trees, which absorb carbon dioxide, are a natural sink for the gas emitted into the atmosphere.
- According to a study trees absorb about 25% of the CO2 released into the atmosphere by the burning of fossil fuels, while the oceans absorb another 25%.
- The half that remains in the atmosphere contributes to global warming.
Reforestation to curb global warming
- Restoration of forests has long been seen as a potential measure to combat climate change.
- What has so far been unclear, however, is how much of this tree cover might be actually possible in the existing conditions on the planet.
No more a vague idea
- The latest special report by the Intergovernmental Panel on Climate Change (IPCC) suggests that an increase of 1 billion hectares of forest will be necessary to limit global warming to 1.5°C by 2050.
- Now, researchers have quantified how much land around the world is available for reforestation, as well as the extent of carbon emissions these would prevent from being released into the atmosphere.
- The new forests planted, once mature, could store 205 billion tonnes of carbon, the researchers calculated.
How much land needs to be reforested?
- The study, by researchers with the Crowther Lab of ETH Zurich University has been published in the journal Science.
- On the basis of nearly 80,000 images from around the world, they calculated that around 0.9 billion hectares of land would be suitable for reforestation.
- If an area of 0.9 billion hectares is indeed reforested, the researchers calculated, it could ultimately capture two-thirds of human-made carbon emissions.
- The estimated land excludes cities or agricultural areas from the total restoration potential as these areas are needed for human life.
- Earth’s continuous tree cover is currently 2.8 billion hectares, and the researchers calculated that the land available could support 4.4 billion hectares, or an additional 1.6 billion hectares.
- Out of this, 0.9 billion hectares — an area the size of the US — fulfil the criterion of not being used by humans.
- That is about two-thirds of the 300 billion tonnes of carbon that has been released into the atmosphere as a result of human activity since the industrial age.
Land available in India
- In India, there is room for an estimated 9.93 million extra hectares of forest.
- India’s existing forest cover makes up 7,08,273 sq km (about 70.83 million hectares) and tree cover another 93,815 sq km (9.38 million hectares), according to the MoEFCCs ‘State of Forest Report 2017’.
- The study found that the six countries with the greatest reforestation potential are Russia (151 million hectares); the US (103 million hectares); Canada (78.4 million hectares); Australia (58 million hectares); Brazil (49.7 million hectares); and China (40.2 million hectares).