The G-20 summit, which begins today in Hamburg, will be President Trump's first. He must face up to and try to resolve many critical issues as he meets with the world's leaders. People will watch especially carefully as he meets with Russia's Vladimir Putin and China's Xi Jinping.

We hope his meetings are fruitful and that he is appropriately tough on or friendly toward his counterparts. But we also hope he completely ignores the lectures and sneering he will likely get from European leaders over the American withdrawal from the Paris climate agreement.

Trump did the right thing in pulling the U.S. out of this farce from the late stages of the Obama presidency. He should feel very confident about his decision.

The reaction by European leaders has been as hysterical and disproportionate as it is hypocritical. German Chancellor Angela Merkel has already telegraphed in advance that she intends to make it an issue and to confront Trump over the Paris agreement specifically.

He should respond to her by first pointing out that the U.S. actually reduced its overall greenhouse emissions faster than Germany over the last decade. Between 2005 and 2015, American emissions fell by 9.9 percent, as compared with Germany's 8.8 percent, even though the U.S. was not a signatory to any carbon emissions treaty during that period.

U.S. energy-related greenhouse emissions also fell by 1.7 percent in 2016, after falling by 2.7 percent the year before. Germany's greenhouse gas emissions rose in both years.

And, again, the reductions in the U.S. did not occur because of any agreement or treaty or grand government plan. They occurred because of the market forces behind America's ongoing natural gas revolution. Thanks to fracking, the U.S. has a cheap and relatively clean supply of energy. Electrical utilities are adapting to this economic reality at such a rapid clip that last year, emissions from electrical generation in the U.S. fell below emissions from the use of fuels for transportation.

Germany, meanwhile, is emitting more greenhouse gases. This is in part because of a political stunt by Merkel herself. She famously announced after the Fukushima reactor disaster that Germany would be phasing out nuclear power. It was her choice, and it will have a much larger effect on world greenhouse emissions than Trump's withdrawal from a nonbinding agreement.

Merkel has also strongly opposed and worked to prevent increased fuel efficiency standards for automobiles in the European Union. To be fair, this is her way of standing up for the interests of a vital German industry. But it makes her criticism of Trump especially ridiculous. Her actions mean something for emissions levels. His decision not to accept arbitrary emissions targets doesn't mean anything. What clearer evidence could there be than the arbitrary emissions targets that Germany has embraced for 2020, which it is on pace to miss by a very wide margin.

Former President Barack Obama negotiated and signed the Paris Agreement in advance of an election. The U.S. voting public had an opportunity to elect a Senate that might stand a chance of ratifying such an agreement or at least of voting in a Congress that would pass laws to honor the agreement. The voters not only declined to do either one but also backed the presidential candidate who colorfully made clear he didn't give a hoot about emissions policy.

If Merkel and other European leaders have a beef, it is not with Trump. It is with the Americans whose priorities he refused to subordinate, even on a purely symbolic basis, to their climate ideology.