Impact Of Fossil Fuel Combustion And Carbon Sequestration On The Flows And Stores Of Carbon

Question 1

Fossil fuel combustion

Answer 1

High global dependency on coal,oil and gas despite renewable energy ( 2013- 87% of energy consumption) highest being oil - 37% of global energy consumption

10 billion tonnes of co2 is released into the atmospheric store annually by fossil fuel emissions, increasing co2 concentration by over 1ppm

1750- anthropogenic activities totalled nearly 2000gt of emissions - 3/4 of which is fossil fuels

879 gt of this remained in the atmosphere - raising co2 conc from 280 40 400 ppm

Anthropogenic carbon emissions contribute less than 10% of the natural influx from the biosphere and oceans to the atmospheric store

2000-2009 human carbon emissions grew faster than in any other previous decade

Without the oceans and biosphere absorbing anthropogenic carbon emissions, the atmospheric concentrations would exceed 500ppm

Anthropogenic activity which impacts carbon stores of the atmosphere, oceans and biosphere

Transfer of carbon from geological stores to the atmosphere and oceans = main cause of global warming

Question 2

Carbon sequestration - part 1

Answer 2

Solution: capture and store the co2 released by power plants and industry

new technology of carbon sequestration called carbon capture and storage (ccs) - limited by high capital costs ( draw and Peterhead project was going to cost £1 ) and it uses large amounts of energy ( 20% of the power plants energy is needed to separate the co2 and compress it )and requires storage reservoirs with specific geological conditions ( porous rocks overlain by impermeable strata)

Currently in pilot testing at a few coal-fired power stations

Stage 1 - co2 is separated from the power station emissions

Stage 2 - co2 is compressed and transported by a pipeline to storage areas

Stage 3 - injected into porous rocks deep underground where it can be permanently stored

1750-2012 net gain of co2 to the atmosphere 113ppm

Question 3

Carbon sequestration - part 2

Answer 3

USA - 40% of all co2 emissions are from coal and gas fired power stations and ccs could reduce these emissions by 80-90%

UK - pilot project is underway at Peterhead in north-east Scotland

Due to cost in North Yorkshire, the Draz project stopped in 2016( it was designed to capture 2 million tonnes of co2 per year )

• plan was to transport carbon by the pipeline to the North Sea and stored in depleted gas reservoirs

Co2 gas can be pumped into manure oil fields ( assam, gujarat and rajasthan ) to extract oil that would otherwise be uneconomic to recover

Limited by economic and geological factors