Donald Trump and Al Gore would no doubt cringe at the thought that politically speaking, they are brothers from different mothers. After all, what do the Republican president and the Democratic presidential wannabe have in common besides the fact that they are both old, white, pompous dudes who live in mansions and hate Hillary Clinton?

Whether they realize it or not, they both believe in the precautionary principle — the notion that even a small chance of a catastrophic event requires sweeping measures to avert it. Nor do they care about the costs of these "sweeping measures" — both in terms of money and individual liberty.

Their only disagreement is about the events in question: Trump invokes this principle in his crusade against Islamist terrorism — and Gore and his fellow global warming warriors against climate change.

Dick Cheney famously declared that if there was even a "1 percent chance" of another 9/11-style attack by al Qaeda, "we have to treat it as a certainty in our response." For all of Trump's criticisms of the Iraq War, he has a natural instinct for this kind of excess. No sooner did the dastardly Manchester attack occur than Trump reiterated, as he had in his inaugural address, that this "wicked ideology must be obliterated."

To that end, Trump, who has never explicitly rejected pre-emptive strikes against states that harbor terrorists, has significantly escalated America's military offensive against ISIS. He has eagerly embraced — and grown — the massive surveillance state he inherited from his predecessors to snoop and spy on Americans. He rejects basic due process rights not just for enemy combatants captured in the theater of war, but even domestic terror suspects such as the New York dumpster bomber. And then there is his plan to subject prospective refugees to "extreme vetting" to ensure with 100 percent certainty that no terrorist enters the country. (Not to be outdone, incidentally, after the London Bridge attack, British Prime Minister Theresa May demanded the authority to censor and control speech on the internet and has also suggested that human rights laws be scrapped if they come in the way of fighting terrorism.)

Given that the odds that Americans will perish in any terrorist attack — not just those involving Islamists — on U.S. soil is 1 in 3.6 million per year — if the trends of the last four decades are any indication, such draconian steps to avert another 9/11-style event won't make Americans substantially safer. But they will make them substantially less free.

Liberals understand this when it comes to dealing with global terrorism. Al Gore himself gave a great speech in 2006 lamenting all the constitutional protections that the war on terrorism was claiming and expressed alarm that the executive branch had been conducing warrantless surveillance of telephone calls, emails and other internet communication inside America.

But when it comes to global warming, Gore's ideological blind spots are more dazzling than the sun. He condemned Trump's pullout from the Paris agreement as "indefensible" and "reckless." Likewise, the ACLU, which has been heroically fighting Trump's travel ban and other constitution-busting moves, bizarrely tweeted that the withdrawal would be a "massive step back for racial justice."

But the fact of the matter is that a pre-emptive strike against climate change will be no less damaging for justice, racial or otherwise.

The goal of the Paris agreement was to keep global temperatures from rising more than 2 degrees Centigrade by 2100. But the most optimistic assessments suggest that even if all the signatories live up to their Paris pledges, it's still a Pollyannaish assumption that won't be met. To exceed the agreement and actually meet its goal would require nothing short of the climate change equivalent of Mao's Cultural Revolution to socially engineer a complete global lifestyle shift.

What will this entail? Certainly something far beyond President Obama's coal regulations, which still wiped out (along with fracking) the coal industry in West Virginia — and, along with it, entire livelihoods. Fracking, incidentally, helped to tap natural gas, which is 50 percent cleaner than coal. But climate change warriors such as the Union of Concerned Scientists don't think that cuts it. They want to settle for nothing short of a complete shift to zero-emission renewables — and rightly so if exceeding the Paris targets are a serious goal. America's love affair with SUVs will also need to be cured. So far every administration has tried to achieve that by raising fuel efficiency standards. But every time car mileage improves, people drive more and emit more. Hence regulators will have to outlaw the internal combustion engine as Gore has long recommended.

And what about those pesky skeptics who question the climate change gloom-and-doom? Do they deserve First Amendment's free speech protections? Gore may cry crocodile tears about the abrogation of civil liberties by the war on terrorism, but Democratic Sen. Barbara Boxer of California singled out Reason Foundation (where I work) as an outfit that is part of the "web of denial" undermining "climate science." Some climate change warriors have called for jailing dissenters, on par with the indefinite detention of alleged suspects in the fight against terrorism. The Democratic Party's 2016 platform wants to criminally investigate whether companies such as ExxonMobil lied about global warming to the public and shareholders back in 1997 (even though the company long ago became an advocate of a carbon tax)!

And whatever Western governments would need to do to avert global warming, India and China have to do much more. The former, after all, "merely" have to embrace more modest lifestyles without cars and air conditioning, the latter would have to abandon hope of ever foregoing mass poverty.

So what should be done about these twin threats — global terrorism and global warming — of the 21st Century? Abandon the precautionary approach that seeks to attack the problem at its root. In the case of Islamic terrorism, the better option would be the one deployed during the Cold War against communism, namely containment and deterrence. Imagine how much more havoc America would have caused in the world if it had decided that this "extremist ideology" didn't have to be managed but obliterated from the face of the earth?

Likewise, on global warming, better than trying to put the world on a radical and painful energy diet to avert the problem in the first place, perhaps look for technical fixes such as carbon sequestration to remove the carbon from the atmosphere and build human defenses against it.

Otherwise, we may well kill humanity in trying to save it.