For the second time in two weeks, President Donald Trump has claimed that the United States is a leader on reducing carbon-dioxide emissions. He said this first at the G20 meeting in Osaka, Japan, and again Monday at the White House in remarks about his environmental record. It's worth understanding this fatuous claim, as the Trump administration is likely to repeat it.

Here is the paragraph that the US inserted into the final communique of the G20 meeting:

"The United States is a world leader in reducing emissions. US energy-related CO2 emissions fell by 14% between 2005 and 2017 even as its economy grew by 19.4% largely due to the development and deployment of innovative energy technologies. The United States remains committed to the development and deployment of advanced technologies to continue to reduce emissions and provide for a cleaner environment."

The statement about the decline in emissions is true but utterly evades the point. In 2005, the US emitted 20.3 metric tons per person, the highest of the world's large economies. In 2017, the US emitted 15.8 metric tons per person, once again the highest of the world's large economies, though slightly lower that Australia and Canada, two other very high emitting countries.

US emissions dropped from a recklessly high level to a still recklessly high level. And with Trump's own policies to promote fossil fuels, even the modest year-to-year declines in emissions are starting to reverse, with emissions up to 16.1 metric tons per person in 2018.

Nature doesn't care about Trump's spin. The US is contributing to a global calamity no matter what Trump says. Carbon concentrations in the atmosphere reached the highest concentration in the past 3 million years, above 410 parts per million. Global warming has created the warmest climate of the past 11,700 years, as renowned climate scientist, Columbia University's James Hansen, notes. US losses from major climate-related events, those with a cost of $1 billion or above, averaged an astounding $150 billion per year in 2016-2018.

When thousands died in Puerto Rico in 2017 as the result of Hurricane Maria, Trump denied it. Alas, Puerto Rico's dead could not respond.

Five large economies are responsible for more than half of the world's emissions: China, India, Japan, Russia, and the US. The world's fate lies in their—our—hands. Of these five, the US has by far the highest emissions per person, with China's per capita emissions, for example, less than half of the US level. The other four countries are sticking with the Paris Climate Agreement, a commitment they reiterated at the G20 Summit. Only Trump has declared the intention to pull out.

We can't be sure of Trump's motivation: sociopathy, politics, pandering to Big Oil, or some combination of these. Whatever the motivation, the outcome is an inhumane act against civilian populations "intentionally causing great suffering, or serious injury to body or to mental or physical health," the definition in international law of a crime against humanity, a point that I have made before.