Carbon Sequestration

What is carbon sequestration?

the process of the capture and long-term storage of atmospheric CO2

What are some of the benefits of carbon sequestration?

• mitigates (slows down) or stops global warming

• reduces the effects of climate change

What are some natural methods of carbon sequestration?

• restoring peat bogs

• afforestation

• wetland restoration

• agriculture

• iron fertilisation

• urea fertilisation

• mixing ocean layers

What are some human methods of carbon sequestration?

• carbon capture and storage (CCS)

• bioenery with CCS (BECCS)

• biochar (bio-charcoal)

• subterranean injections

• deep basalt storage

• acid neutralisation

How is restoring peat bogs used to sequester carbon?

• peat soil is the biggest store of carbon in the UK

• creating new peat bogs, or enhancing existing ones, can increase carbon storage

How is mixing ocean layers used to sequester carbon?

1. Moving gases and nutrients around the ocean layers

2. Large vertical pipes pump nutrient-rich water to the surface

3. Triggers algal blooms, which trap carbon when they grow

How is afforestation used to sequester carbon?

• the replanting of trees to trap CO2

• trees can be harvested and used in carbon capture storage (CCS)

• incorporates carbon from atmospheric CO2 into biomass

How is wetland restoration used to sequester carbon?

• 14.5% of the world's soil carbon is found in wetlands

• only 6% of the world's land is composed of wetlands

How are iron and urea fertilisation used to sequester carbon?

1. Iron-rich dust and/or urea (a nitrogen-rich substance) are deposited into the oceans to fertilise them

2. Encourages phytoplankton growth

3. Phytoplankton remove carbon from the atmosphere

How is agriculture used to sequester carbon?

• all crops absorb CO2 during growth

• agriculture contains 1,500 gigatonnes of organic carbon in soils globally

• reducing ploughing, which damages the soil

• reducing the usage of chemical fertilisers

• avoiding overgrazing to allow biomass to return to the soil

• allowing degraded land to recover and slow down the release of carbon

How is carbon capture and storage (CCS) used to sequester carbon?

1. Extracts carbon from the atmosphere or from waste pipes of power plants which burn fossil fuels

2. The waste carbon is pumped underground into an unused space

How is bioenergy with CCS (BECCS) used to sequester carbon?

when biomass is burned, the CO2 is then captured and stored underground, which prevents it from going into the atmosphere

How is biochar (bio-charchoal) used used to sequester carbon?

1. Charcoal is made and then added to the soil

2. Increases the soil's fertility and agricultural productivity

3. Traps carbon into the soil

How are subterranean injections used to sequester carbon?

carbon dioxide is injected into depleted oil and gas reserves (continental crust), or into oceanic crust

How is deep basalt storage used to sequester carbon?

1. Carbon dioxide is mixed with basalt deep in the oceans

2. Carbonate and hydrate minerals are created

3. These minerals are more dense and settle on the sea bed, unlikely to rise and leak

How is acid neutralisation used to sequester carbon?

1. As carbon dioxide mixes into the oceans, they gradually become more acidic

2. The oceans can then absorb less carbon dioxide as species such as phytoplankton would cease to exist

3. Adding limestone to the oceans could neutralise the sea water and increase absorption once again