Your curve charts show the cost of servicing debt, not cost of extraction. Between 2007 and 2014 mining companies took on a lot more debt to stay in operation while resource prices were low due to global economic meltdown. They are loaded down with debt but not because their costs to extract have risen. Instead, it's due to rapidly lowering demand and built up stockpiles that depress the price. In fact, the extraction price may have actually gone down due to new technology.

In the US, coal extraction dropped 10.3% in 2015 but coal consumption dropped 13.1% and as a result US stockpiles of coal rose 20.6% to 238.8 million short tons or 3.5 months-worth of current US consumption. Employment at US coal mines dropped 12.0% during this period indicating that productivity increased during that time. At the 2015 consumption rate of 798 million short tons, the US estimated recoverable reserves (the amount that could be mined using only present technology) of 255.8 billion short tons would last 320 years.

In the US at least, coal production is at its lowest levels since 1986, but is still outstripping consumption and leading to the highest year-end stockpiles ever recorded.

http://www.eia.gov/coal/annual/ http://www.eia.gov/energyexplained/index.cfm?page=coal_reserves

From what I read (including your article at the top) it's demand for coal that has peaked, not supply. Production has decreased in China because there was a general economic slowdown from previous over-stimulation. For example, in the previous years, Chinese firms used a lot of coal to make a lot of steel at a loss, now it's sitting waiting to be used and the steel plants are running at lower capacity. With Beijing having more and more days of unbreathable air each year, the Chinese government is under some pressure to reduce pollution. Also, China seeks to bolster their geopolitical image and they aren't going to do it on human rights, so they're working on environment. PRC has a lot of self-made problems to address in the next few years, but a lack of energy isn't one of them.

The country's National Energy Administration is suspending 85 planned or in-progress coal power plants -- not because they're threats to the environment and public health (which they are), but because they don't fit in with China's latest Five Year Plan. It's targeting a coal capacity limit of 1,100GW, but the plants would have brought it to 1,250GW.

And now they tell us that they care for people health, they don't, just peak coal passed.

And this is that happens if Chinese coal production starts to fall

Does it mean what Chinese cheap product won't be so cheap?

Yes, and in long term it can even mean that it won't be any Chinese products for export.

Things are bad

China produced 263.75 million tonnes of coal in May, sliding 15.5% year on year, data from the National Bureau of Statistic (NBS) showed on June 13.

That dipped 1.6% on month, compared with the decline of 8.77% in April, data showed.

China’s raw coal output stood at 1.34 billion tonnes over January-May, dropping 8.4% from the year prior, compared with the decline of 6.8% in January-April.

Older useful topic - http://www.personal-view.com/talks/discussion/10581/energy-issues-in-china/p1