If you believe the BBC, the US and Chinese presidents signed a major deal on climate at the G20 summit in China today.

Actually, though, the deal means nothing because it’s non-binding and anyway the agreed targets – set at the COP21 fiasco in Paris last year – are a total waste of time.

Yes, of course, papers like the New York Times have tried to put a brave face on it:

At a ceremony in this picturesque lakefront city, the two leaders hailed the adoption of the Paris agreement as a critical step toward bringing it into force worldwide. Together, China and the United States generate nearly 40 percent of the world’s emissions, not far from the threshold of 55 percent required for the global pact to take effect.

“Despite our differences on other issues, we hope our willingness to work together on this issue will inspire further ambition and further action around the world,” Mr. Obama declared.

Mr. Xi praised the Paris agreement as a milestone, adding, “It was under Chinese leadership that much of this progress was made.”

But the reality, as this analysis earlier in the year from the Global Warming Policy Foundation made clear, is that the agreement made in Paris – and now being endorsed by Presidents Obama and Xi – is toothless and therefore meaningless.

As the author of the analysis, Professor David Campbell of Lancaster University explains, the agreement gave China (and other “developing” countries like India) carte blanche to go on producing as much CO2 as they like. Otherwise China would never have signed it.

The devil lies in Article 4 (7) of the Paris agreement:

The extent to which developing country Parties will effectively implement their commitments under the Convention. . .will take fully into account that economic and social development and poverty eradication are the first and overriding priorities of the developing country Parties.

Both India and China count as “developing” countries. What this subclause means is that no matter what commitments they may make to reduce their CO2 emissions, these must take second place to economic growth. So basically they can produce as much CO2 as they like without being in breach of the Paris Agreement. No wonder they put up so little resistance.

Not even “developed” countries are obliged to do anything, either. That’s because – at the behest of the US delegation in Paris – the word “should” was inserted into a key clause instead of “shall.” Otherwise, as Paul Homewood explains, it would have become legally binding and would have had to be ratified by Congress.

But here’s the most stupid thing of all: even if all the countries in the world were to hold true to the vague, non-binding commitments they made in Paris – which of course they won’t – the resultant reduction in global warming would be 0.048 degrees C by the end of the century.

All this fanfare, all this regulation, all this expense to reduce “global warming” by less than one twentieth of a degree.