Will Forest Fires be our nemesis ?

In southern California, December is meant to bring the start of rainy season. Not in 2017. The Thomas fire, the worst of those that roiled the region that year, grew 50,000 acres in one day, eventually burning 440 sq miles and forcing the evacuations of more than 100,000 Californians. A week after it was sparked, it remained, in the ominous semi-clinical language of wildfires, merely “15% contained”.

Five of the 20 worst fires in California history hit the state in the autumn of 2017, a year in which more than 9,000 separate fires broke out, burning through almost 1.25 m acres – nearly 2,000 sq miles made soot. 

In the summer of 2018, the fires were fewer in number, totalling only 6,000. But just one, made up of a whole network of fires, together called the Mendocino Complex, burned almost half a million acres alone. 

In total, nearly 3,000 sq miles in California turned to flame, and smoke blanketed almost half the country. 

Things were worse to the north, in British Columbia, where more than 3 m acres burned, producing smoke that would travel across the Atlantic to Europe. 

Then, in November, came the Woolsey Fire, which forced the evacuation of 170,000, and the Camp Fire, which was somehow worse, burning through more than 200 square miles and incinerating an entire town so quickly that the evacuees, 50,000 of them, found themselves sprinting past exploding cars, their sneakers melting to the asphalt as they ran. It was the deadliest fire in Californian history.

When trees die – by natural processes, by fire, at the hands of humans – they release into the atmosphere the carbon stored within them, sometimes for as long as centuries. In this way, they are like coal. This is why the effect of wildfires on emissions is among the most feared climate feedback loops – that the world’s forests, which have typically been carbon sinks, would become carbon sources, unleashing all that stored gas. 

The impact can be especially dramatic when the fires ravage forests arising out of peat. Peatland fires in Indonesia in 1997, for instance, released up to 2.6gigatons (Gt) of carbon – 40% of the average annual global emissions level. 

A focus on fossil fuel emissions reduction as the primary solution to reversing climate change will continue to be ineffective

Replacing snow covered land with trees that absorb more sunlight in northern countries can actually accelerate warming regionally, creating a positive feedback loop that leads to further loss of highly-reflective snow and ice.

Climate researchers often suggest that the greatest potential for carbon sequestration in forests lies in the tropics; avoided deforestation, forest restoration and afforestation in these regions can play a significant role in mitigating global climate change.

Grassland biomes constitute approximately 40% of the global land surface area and possess massive potential for sequestering carbon in arid and semi-arid areas of the world. Healthy grasslands provide habitat for a biologically diverse range of plant and animal species, and also serve as a large reserve for soil carbon. Grasslands that sustain abundant stores of SOC have higher rates of water infiltration and retention and are less susceptible to environmental degradation such as soil erosion and drought. Although grasslands are currently facing desertification around the globe, proper land management can restore vegetation cover to protect soils from erosion and enhance the carbon sequestration capacity of these vital ecosystems.

While forests and dryland ecosystems contain the most soil carbon globally, the carbon density of wetland ecosystems is three and six times that of forests and grasslands/shrublands, respectively. The deep organic-rich soils of coastal wetlands contain carbon reserves that have been sequestered over millennia. These tidal ecosystems are able to store large quantities of carbon for two primary reasons: high-nutrient conditions that promote the rapid growth of carbon-sequestering plant biomass, and anaerobic soils that suppress microbial decomposition in the water-logged environment, allowing for long-term carbon storage. Tidal saline wetland ecosystems, including salt marshes and mangrove swamps, exhibit remarkable rates of below ground biomass production and enormous capacity as carbon sinks.

Conclusion : A focus on fossil fuel emissions reduction as the primary solution to reversing climate change will continue to be ineffective. Arbitrary goals to reduce emissions by 10, 30, 50 or even 80 percent are not going to prevent future warming. Basic scientific principles dictate that atmospheric CO2 concentrations will not decline without a significant rise in the carbon sequestration mechanisms of the biosphere. The good news is that there is enormous carbon sequestering potential in multiple ecological systems around the globe. The only question now is whether we will work to enhance the carbon storage capacities of nature or effectively continue to weaken them.

Acknowledgement : Text sourced entirely from this link.