The world is getting a better understanding of just how important forests are in the global fight against climate change.
New research, published in Nature Climate Change and available on Global forests Watch, found that the world’s forests sequestered about twice as much carbon dioxide(CO2) as they emitted between 2001 and 2019. In other words, forests provide a ”carbon sink” that absorb a net 7.6 billion metric tonnes of CO2 per year. 1.5 times more carbon than the US emits annually.
Unlike other sectors, where carbon makes a one- way trip to the atmosphere, most forest act as a two way highway, absorbing CO2 when standing or regrowing and releasing it when cleared and degraded.
Before now, scientists estimated these global ”carbon fluxes” from the sum of countries-reported data, creating a coarse picture of the role forests play in both carbon emissions and sequestration.
With the new data that combine ground measurements with satellite observations, we can now quantify carbon fluxes consistently over any area, from small local forests to countries to entire continents.
Using this more granular information, we found that the world’s forest emitted an average of 8.1 billion metric tonnes of carbon dioxide into the atmosphere each year due to deforestation and other disturbances, absorbed 16 billion metric tonnes of CO2 per year.
- Only one tropical rainforest remains a strong carbon sink. Tropical rainforests are far and away the most important ecosystems for mitigating climate change. They collectively sequester more carbon from the atmosphere that temperate or boreal forests, but they’re also increasingly destroyed for agricultural expansion. Of the worlds three largest tropical rainforests, only the Congo has enough standing forest left to remain strong net carbon sink. It sequesters 600 million metric tonnes more carbon dioxide per year than it emits, equivalent to about one-third of the CO2 emissions from the U.S. transportation. Protecting the remaining forests in all the three regions is critical to mitigating climate change.
- Protected areas help conserve forest carbon sinks.The new map reveals that 27% of the world’s net forest carbon sinks falls within protected areas. Looking at individual areas demonstrates just how effective these designations can be in keeping CO2 in forests. For example in Brazil, a stark contrast in carbon emissions is evident between the protected Menkragnoti indigenous reserves and the surroundings unprotected forest. Forest in the reserve continues to absorb approximately 10 millions metric tonnes of carbon dioxide more from the atmosphere than they emit every year-equivalent to the annual carbon emissions from more than 2 million cars. The areas surrounding the Menkragnoti indigenous reserves has become a net carbon sources due to cleaning for mining, pasture and soy. Recognizing indigenous peoples and local communities as owners of their lands, is proven strategy to protect standing forests and enhance carbon stored in them.
- Protecting standing forests is critical for climate mitigation. Overall, the data show that keeping existing forests standing remains our best hope for mitigating the vast amounts of carbon forests store and continuing the carbon sequestration that, if halted, will worsen the effects of climate change. While planting trees the right way or letting them regrow naturally can play role in mitigating climate change and helping communities adapt its effects, the new data show that forests that have sprouted up in the last 19 years represents less than five percent of the current global forest sink. Although important to give these young forest the chance to grow into old ones, protecting primary and mature secondary forests today is most important for curbing climate change. With these new maps, we can identify with unprecedented detail those forests that are capturing and emitting the most carbon. The maps can continually improved as better data become available. This makes us one step closer to tracking progress towards reducing emissions from deforestation and identify where forests are being successfully managed-and where they need more protection.
Source: The Nation_January 27,2021_By Nancy Harris and David Gibbs- Contributors