ConservativeHome apologies if it has misread Donald Trump’s State of the Union address, but it can find no reference in its text to a plan for reducing America’s carbon emissions.

Instead, the President says that “the United States has become the number one producer of oil and natural gas in the world, by far”, adds that the country is now energy independent, and claims that “energy jobs are at a record high”.

Much in America depends on the actions of the individual states, and Trump did produce a proposal to plant a trillion trees.  But his views on climate change are ambiguous, and he is no respecter of international orthodoxies on the subject – having pulled the United States out of the Paris climate agreement.

So much for one of the world’s two biggest powers.  What of the other one?  As Ted Christie-Miller of Onward pointed out on this site yesterday, China “has overseen a 321 per cent increase in emissions. Xi Xinping’s country is currently responsible for 26 per cent of global emissions, and rising”.

Some claim that China will forsake coal for renewables, but the proof of the pudding will be in the eating.  In short, neither it nor America is currently doing anything that is likely to cheer Greta Thunberg.  Or meet the more modest achievement of getting tangible gain from the coming Climate Change Summit in Edinburgh.

This is the background against which to view claims that Boris Johnson and his government are in a position to provide international leadership on climate change.  In some policy areas, such as Iran, it’s just about possible to believe that the Prime Minister can act as a bridge between the United States and Europe.

In this one, it’s very difficult indeed to see how he can wring any meaningful gain from the coming summit.  This puts the row over Claire Perry O’Neill’s firing by Johnson as head of the summit into perspective.  Frankly, it will matter little who gets the gig.  Perhaps this explains why both David Cameron and William Hague have turned it down.

The Prime Minister would do better to provide a coherent account how the Government’s will achieve net zero carbon emissions by 2050.  This is a legacy pledge of Theresa May’s, tossed out during her last days in office, and it isn’t at all clear how it will be met.

It will be said that Britain has succeeded in both reducing its emissions and growing the economy since 1990, but much depends on how one slices and dices the figures.  And environmental campaigners point out that we have effectively exported slice of our emissions through carbon credits.

The Government is committed to lowering energy bills, opposing fracking – and going ahead with a mass of road schemes championed by the “Brexity Hezza” himself.  Ministers couldn’t explain yesterday how much the earlier ban on hybrid vehicles will cost or what will replace the vanishing fuel duty.

There is a sunnier side of the street. Ministers will support floating wind farms, gas from hydrogen production and nuclear energy, including fusion.  The Conservative Manifesto promises to invest £500 million to help energy intensive industries move to low carbon techniques.

The summit will provide pictures, declarations and speeches – including an engaging one, we expect, from the Prime Minister as usual.  The event will look and sound impressive.  But it will be an emperor with no clothes.