Fossil fuels are living biomass that gets energy from the sun. They release this energy during combustion. Renewables are currently low but increasing. Oil is the fossil fuel most widely used worldwide. In summer, photosynthesis takes more carbon out of the atmosphere.

In the 2007-2008 crises, consumer demands fell with energy prices. The Arab springs and Libyan crises brought shortages in oil so the price rose again.

The 2015 Paris agreement was the first legally-binding global climate change treaty with the long term coal of keeping global temperatures below 2 degrees higher than pre-industrial levels. Serious reductions are needed but there has not been a great deal of difference. In 2015, 11 billion tonnes of fossil fuels were consumed.

Global warming is real as 2015 had record global temperatures and 2016 as the longest hot spell for 137 years.  Warmer winters could make heating prices fall.

India gets 66% of its energy from coal and produces 6% of global emissions. It wants to reduce its dependence on imports by burning more domestic coal to enable development through infrastructure and to support the growing middle class with 600 million new electricity users. Child labour in these mines keeps the prices low but they do not receive an education.

OPEC regulates the supply and demand of oil. US fracking has increased which has led to a drop in oil prices. OPEC must cut their prices to compete and maintain a market share. Fracked gas emits less carbon dioxide than coal so in the US co2 emissions fell by 7.7% but oil consumption rose by 9%.

Carbon is present in the atmosphere, hydrosphere, lithosphere and biosphere. It moves through the spheres in a closed system with sources adding carbon to the environment and sinks removing it. Negative feedback is stabilising as change is cancelled out, whereas positive feedback triggers other changes.

The water cycle drives the carbon cycle through surface run off and rivers that transport erodes material into the oceans.

The geological carbon cycle is the slow part. Lots of carbon is stored in rocks and sediments with reserve turnover rates of 100,000 years. Organic matter that is buried takes millions of years to turn into fossil fuels. The mantle releases terrestrial carbon when a volcano erupts. This goes into the atmosphere where it can rain where the acid dissolves the rocks and weathering occurs. Rivers transport weathered rocks into the ocean where they sink to the beds and build up to form sedimentary rocks. They are then either subducted along plate boundaries to wait for another eruption or heat alters them to create metamorphic rocks and release carbon dioxide.

Eyjafjallajokull erupted 30,000 tonnes of carbon dioxide daily which was below 0.3% of total greenhouse gases produced that year. As temperatures rise, there will be more evaporation, more acid rainfall and more weathering of rocks.

The bio-geochemical part is faster with large fluxes and a shorter turnover. Carbon is sequestered in the atmosphere, oceans, vegetation, soil and fresh water…


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