The primary cause of the better mood is the deal between New Hope Corporation and Rio Tinto with the former buying a 40% stake in the Bengalla coal mine in the Hunter Valley of New South Wales from the latter at the handsome price of $865 million.

A second reason is a takeover bid for Australian-listed, but South African-focused, Universal Coal from Ichor Coal.

The third is the stout defence of coal from BHP Billiton as the debate over the fossil fuel heats up ahead of next month’s big climate change conference in Paris.

Wrap those events into a neat parcel and it is hard to overlook the fact that this was a week when coal fought back with actions as well as words – capped off with a fistful of dollars.

The biggest deal was undoubtedly the Bengalla transaction, not simply because of the price, but also because of the potential to trigger a bidding war if the other companies that own a slice of the mine exercise their rights to match the offer from New Hope.

The next few days should reveal whether the Australian industrial conglomerate Wesfarmers, along with the Taiwan power company Taipower and the Japanese trading house Mitsui are prepared to counterbid – which they are allowed to do under joint venture rules.

Given that the $865 million appears to be at the top end of estimates, especially in the current market for coal, it is a reasonable assumption that the option for joint venture partners to meet, or better any offer will be allowed to lapse.

However, if Wesfarmers and the other co-owners of Bengalla do match New Hope’s price then a bidding war could be ignited. That would be an even more encouraging sign that coal remains a very valuable commodity which can attract high levels of buyer interest.

The second corporate deal is much smaller than Bengalla, valued at around $81 million, but the fact that Ichor Coal is pushing ahead with its offer of 16c a share for Universal is a positive comment on the appetite for coal investments.

The other interesting point about Ichor’s offer is that it has little hope of succeeding because Universal shares are trading on the ASX at 18c.

Either Ichor increases its bid to match (or beat) the market, or Universal investors take a haircut by accepting 16c when there’s 18c on offer in the open market – an unlikely event.

There is also another way of looking at the Bengalla deal because it does involve a buyer and a seller with Rio Tinto the vendor of its 40% stake in the mine, a move that could possibly signal that the start of a broader sell-down of coal assets.

That could happen because coal has become a relatively small profit contributor for Rio Tinto, and a poor performer on investment fundamentals such as return on capital invested.

Management at the diversified mining giant will be looking hard at whether funds tied up in coal could earn a higher return by expanding copper production, which is the metal most likely to recover quickly from the current downturn, or even iron ore where it has a significant cost advantage over most rivals.

Another influence on Rio Tinto is BHP Billiton’s action in downsizing its coal exposure by spinning off assets into South32, and then there’s the pressure from international investors who are worried by the ongoing scare campaign over coal.

What one mining giant does the others inevitably follow, a trend likely to end with the creation of companies that are coal specialists, such as New Hope, which appeal to investors who are comfortable with coal exposure in their portfolios.

That leads to the third event of the week, BHP Billiton’s stout defence of coal in the face of preparations for the Paris conference and a warning from Bank of England Governor Mark Carney that some fossil fuels could become stranded courtesy of government action.

Carney’s comments at a dinner in London were designed to remind investors of the potential for regulatory risk should governments tighten carbon dioxide emission laws.

BHP Billiton’s view, published on the same day, was along the lines of whatever happens it would not be too badly affected by tighter carbon laws, suffering a possible 5% fall in asset values if a price of $US80/tonne was put on carbon dioxide – six times the current CO2 price under Europe’s carbon trading scheme.

In other words, everything that is happening in coal today has a price and in every case someone is prepared to pay.