Something strange is happening to Elon Musk.

First, he joined President Donald Trump's orbit as a business advisor. Now, the evangelist for clean energy who oversees Tesla, SolarCity and SpaceX has endorsed Trump's controversial secretary of state pick, the longtime ExxonMobil CEO Rex Tillerson.

This is the equivalent of the Wright Brothers endorsing the inventor of the horse and buggy.

The endorsement is surprising because Tillerson's views on climate and energy are diametrically opposed with Musk's. (And that's an understatement.)

Tillerson has never held a job outside of Exxon, and due to his fossil fuel industry ties, he is opposed by virtually every environmental group as well as most Senate Democrats.

In a series of Tweets on Tuesday, which were prompted by The Economist's endorsement of Tillerson, Musk explained his reasoning.

@TheEconomist This may sound surprising coming from me, but I agree with The Economist. Rex Tillerson has the potential to be an excellent Sec of State. — Elon Musk (@elonmusk) January 24, 2017

When asked to expand on why he has this view, Musk said:

@danahull I share The Economist's opinion that he should be given the benefit of the doubt unless his actions prove otherwise — Elon Musk (@elonmusk) January 24, 2017

Musk's stance toward Tillerson, who led the world's largest publicly traded oil and gas company since 2006, contrasts with his stated priorities of advocating and working toward a carbon neutral world.

"Global warming is a serious crisis, and we need to do something about it," Musk said in October of 2016. "We need to do everything we possibly can to accelerate the transition to sustainable energy."

Exxon, where Tillerson spent his entire career, has been shown to have researched climate science since the 1970s and then paid groups to try to convince the public that climate science was uncertain.

This tactic, which was revealed through investigative reporting by several media outlets, is currently under investigation by two state attorneys general and the Securities and Exchange Commission.

Secretary of State-designate Rex Tillerson testifies on Capitol Hill in Washington, Wednesday, Jan. 11, 2017. Image: J. Scott Applewhite/AP

In a speech at the Sorbonne in France in 2015, Musk decried the climate change disinformation campaign from the fossil fuel industry, urging the young audience in attendance to "fight the propaganda" from the carbon industry. He compared that campaign to the tobacco industry's bid to convince the public that the link between smoking and cancer was tenuous.

Interestingly, that precise analogy, which invokes a federal law known as the Racketeer Influenced and Corrupt Organizations Act, or RICO, is now being used by investigators in the Exxon case, known by the hashtag #ExxonKnew.

Unlike Musk, Tillerson does not see climate change as an urgent threat, let alone a high priority for the State Department.

During his confirmation process he said he does not see greenhouse gas emissions from fossil fuel burning as the main cause of global warming.

"The increase in the greenhouse gas concentrations in the atmosphere are having an effect," Tillerson said during the hearing on Jan. 11. "Our ability to predict that effect is very limited."

In response to written questions from Sen. Ben Cardin (D-Maryland), Tillerson departed even further from the scientific consensus, saying that greenhouse gas emissions from fossil fuel burning are "a factor in rising temperatures." However, he said: "I do not believe the scientific consensus supports their characterization as the "“key” factor."

In reality, there is virtually no debate in the scientific community about whether greenhouse gas emissions are the main cause of global warming since the preindustrial era. The U.N. Intergovernmental Panel on Climate Change, in its most recent report in 2013, said as much, as have numerous other authoritative reports.

Tillerson and Musk do agree on one thing when it comes to climate change, however. Both men think the most economically efficient solution to the problem would be to place a carbon tax on fossil fuels to discourage their use.

"The fundamental problem is the rules today incent[ivize] people to create carbon; this is madness," Musk said during his address in France.

"So what can you do? Whenever you have the opportunity, talk to your politicians, ask them to enact a carbon tax."

While a carbon tax is viewed as an elegant solution to climate change from an economic standpoint, it has long been seen as politically impossible, at least in the U.S.