Wednesday, October 18, 2017

Why China and coal matter

China is by far the world's largest emitter of CO2.   This chart, from Global Carbon Project, shows the massive jump in emissions since 2000, as Chinese economic growth exploded, and the recent peak as (a) economic growth slowed and (b) the government started to seriously address air pollution.  US emissions have fallen, because coal-powered generation has been replaced by renewables and gas.  European emissions have fallen because of EU climate change policies including the Energiewende in Germany (more on that in a separate post)  India's CO2 emissions continue to grow rapidly, but the shift away from coal in India does seem to have begun.  Remember: to cut the level of CO2 emissions by 80% over the next 30 years, we'll have to reduce them by about 5% per year.




You get a different picture if you look at emissions per capita.  The US is among the highest CO2 emitters per capita (Australia is higher).  But it has also fallen the most.  In the US economic growth has decoupled from emissions.  Emissions per capita are back where they were in the 60s.  But remember, what matters for the climate is total emissions.  We need to get total emissions as close to zero as we can.



The biggest source of emissions is  burning coal. The next biggest is burning oil, mostly for transport.  Gas is way behind, because it produces half the emissions of coal for the same output.  Even better, gas generation can be scaled up or down quickly in response to demand fluctuations.  So we should concentrate of removing coal from power generation and on electrifying transport.  That doesn't mean we should ignore other sources of carbon.  Coal is used to make iron and steel, so we'll need to find a way to do that efficiently using renewables.  Cement production involves baking calcium carbonate to drive off the CO2, so we'll need to find different ways of making cement.





Around the world, coal is being replaced in electricity generation by renewables, gas and nuclear.   Electric car sales will explode over the next 10 years.  And China, the world's largest CO2 emitter is central to both these trends.  The USA is very important too, and the good news is that despite the orange clown in charge, her emissions will go on falling because states, municipalities and companies want clean power, and because the economics now favour renewables.

This year will probably show the peak in global CO2 emissions.   But the initial rate of decline in emissions will be slow.  Too slow.  World temperatures are rising by 0.2 C every decade.  We need to stabilise the level of CO2 in the atmosphere, which means we have to reduce CO2 emissions to below the rate which natural processes take CO2 out of the atmosphere.  And we need to do that fast.

[All charts from Global Carbon Project]

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