[Mission 2024] STATIC QUIZ, 10 November 2023 – Environment

Solution: c)

Carbon sequestration is a crucial part of the global carbon cycle, as it is the process of capturing and storing atmospheric carbon dioxide. One of the ways this happens is when forests and other land vegetation absorb carbon dioxide during photosynthesis.

According to a 2014 NASA-led study, tropical forests remove up to 30 per cent of human carbon dioxide emissions from the atmosphere and make for an important carbon sink — an area which absorbs more carbon than releases it. Therefore, they have a significant role in keeping global temperatures low.

Solution: b)

Statement 3 is incorrect.

Carbon sinks are natural systems that suck up and store carbon dioxide from the atmosphere. The Earth’s land and oceans absorb about half of all carbon dioxide emissions from human activities.

Mangroves, seagrass beds and salt marshes store at least ten times more carbon than continental forests.

Sedimentary rocks in the Earth’s crust contain loads of carbon compounds, including the hydrocarbons we use as fossil fuels that leads to excess carbon dioxide in our atmosphere.

A forest is considered a carbon sink if it absorbs more carbon than it releases. Worryingly, the Amazon rainforest is now releasing instead of absorbing carbon dioxide.

Solution: b)

Statement 3 is incorrect.

Kelps cover 25 per cent of the world’s coastlines and provide food and shelter for fish, invertebrates and marine mammal species. They also offer crucial services such as carbon sequestration and erosion control, according to scientists.

But kelps are increasingly threatened by climate change, eutrophication and shoreline development, among other human-induced stressors.

One such threat is from bryozoa, moss animals that grow as mats on kelps. They drive the seaweed to sink into the seafloor and disintegrate.

The outbreak can be linked to high temperatures. For example, in 2015, researchers observed an expansive outbreak of bryozoa. These observations coincided with ‘the blob’, a marine heat wave that emerged across the northeast Pacific Ocean, according to a report.

Dense kelp beds in warmer and less wave-exposed sites are more susceptible to bryozoan outbreaks.

Seaweeds are farmed as they have industrial applications. They can be harvested to extract biostimulants for plant growth. They also can help in long-term carbon sequestration and regeneration of ocean habitats.

Solution: a)

Only Statement 3 is correct.

Net-zero, which is also referred to as carbon-neutrality, does not mean that a country would bring down its emissions to zero. Rather, net-zero is a state in which a country’s emissions are compensated by absorption and removal of greenhouse gases from the atmosphere.

Absorption of the emissions can be increased by creating more carbon sinks such as forests, while removal of gases from the atmosphere requires futuristic technologies such as carbon capture and storage.

The net-zero goal does not figure in the 2015 Paris Agreement, the new global architecture to fight climate change. The Paris Agreement only requires every signatory to take the best climate action it can.

Solution: a)

A “carbon credit” (also known as a “carbon offset”) is an electronic and serialized unit that represents one ton of CO2 equivalent that is reduced, avoided, or sequestered from projects applying an approved carbon credit methodology.

Decarbonization means the reduction of carbon. More specifically, the term refers to the conversion of the economic system or individual carbon emitting entity converting to reduce the carbon intensity of its (direct or value chain) emissions over time.